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静载试验规范内容静载试验规范内容 附录C 浅层平板载荷试验要点 C.0.1条 地基土浅层平板载荷试验可适用于确定浅部地基土层的承压板下应力主要影响范围内的 22承载力。承压板面积不应小于0.25m,对于软土不应小于0.5m。 C.0.2条 试验基坑宽度不应小于承压板宽度或直径的三倍。应保持试验土层的原状结构和天然湿度。宜在拟试压表面用粗砂或中砂层找平,其厚度不超过20mm。 C.0.3条 加荷分级不应少于8级。最大加载量不应小于设计要求的两倍。 C.0.4条 每级加载后,按间隔10、10、10、15、15min,以后为每...

静载试验规范内容
静载试验 规范 编程规范下载gsp规范下载钢格栅规范下载警徽规范下载建设厅规范下载 内容 附录C 浅层平板载荷试验要点 C.0.1条 地基土浅层平板载荷试验可适用于确定浅部地基土层的承压板下应力主要影响范围内的 22承载力。承压板面积不应小于0.25m,对于软土不应小于0.5m。 C.0.2条 试验基坑宽度不应小于承压板宽度或直径的三倍。应保持试验土层的原状结构和天然湿度。宜在拟试压表面用粗砂或中砂层找平,其厚度不超过20mm。 C.0.3条 加荷分级不应少于8级。最大加载量不应小于设计要求的两倍。 C.0.4条 每级加载后,按间隔10、10、10、15、15min,以后为每隔半小时测读一次沉降量,当在连续两小时内,每小时的沉降量小于0.1mm时,则认为已趋稳定,可加下一级荷载。 C.0.5条 当出现下列情况之一时,即可终止加载: 1.承压板周围的土明显地侧向挤出; 2.沉降s急骤增大,荷载-沉降(p-s)曲线出现陡降段; 3.在某一级荷载下,24小时内沉降速率不能达到稳定; 4.沉降量与承压板宽度或直径之比大于或等于0.06。 当满足前三种情况之一时,其对应的前一级荷载定为极限荷载。 C.0.6条 承载力特征值的确定应符合下列规定: 1.当p-s曲线上有比例界限时,取该比例界限所对应的荷载值; 2.当极限荷载小于对应比例界限的荷载值的2倍时,取极限荷载值的一半; 23.当不能按上述二款要求确定时,当压板面积为0.25-0.50m,可取s/b=0.01-0.015所对应的荷载,但其值不应大于最大加载量的一半。 C.0.7条 同一土层参加统计的试验点不应少于三点,当试验实测值的极差不超过其平均值的30%时,取此平均值作为该土层的地基承载力特征值f。 ak 附录D 深层平板载荷试验要点 D.0.1条 深层平板载荷试验可适用于确定深部地基、土层及大直径桩桩端土层在承压板下应力主要影响范围内的承载力。 D.0.2条 深层平板载荷试验的承压板采用直径为0.8m的刚性板,紧靠承压板周围外侧的土层高度应不少于80cm。 D.0.3条 加荷等级可按预估极限承载力的1/10~1/15分级施加。 D.0.4条 每级加荷后,第一个小时内按间隔10、10、10、15、15min,以后为每隔半小时测读一次沉降。当在连续两小时内,每小时的沉降量小于0.1mm时,则认为已趋稳定,可加下一级荷载。 D.0.5条 当出现下列情况之一时,可终止加载: should be tightened, no loose, Terminal Board wiring should be one on each side, no more than two. J, shielded wire, spare wire binding order, reliable grounding. 7.7 quality standard 7.7.l cables through the cable embedded tube making use of galvanized steel pipe, tube ends without burrs, smooth. 7.7.2 pipe does not allow bending, bending the bend radius should be ? 4 times times the outer diameter of the tube in. 7.7.3 ellipticity of a bent tube, pipe diameter ? 60mm, not >8%, diameter >760mm, not >6%. 7.7.4 making cables buried piping application root production, growing where interface is required, only straight pipe, only the wire port connections, welded connections are not allowed. 7.7.5 service sleeve should have a good grounding. 7.7.6 cable trays installation, burrs and dirt and corrosion treatment should be carried out, install the bridge ... 7.8.1.7 piping and piping, equipment and equipment or piping and other equipment shall have sufficient expansion gap in hot situations. 7.8.1.8 metal temperature of the insulating layer (hot) = shell-wall temperature of environment temperature ? 40 ? c. 7.8.2 paint 7.8.2.l paint of equipment and pipelines should have at least a primer (red paint) and finish. 7.8.2.2 paint appearance color uniform, without paint, rust, flaking, wrinkles, flow marks, scum, paint particles and visible brush marks. 7.8.2.3 interlayer should be tight and without stratification. 7.8.2.4 pipelines asphalt, fiber glass fabric corrosion, external appearance should never show surrounded by glass fiber cloth uniform, dense, painted pitch inspection should be no delamination, cavitation, homogeneity of asphalt coating, brushing each layer thickness in accordance with design requirements. Standard 7.9 7.9 structure placement process. 1 fair-faced concrete is a concrete surface without any decoration, structure appearance quality of concrete structure that is able to display strength and aesthetic perception of quality standards. Construction technology requirements are as follows: template template Panel selection and processing require plate high strength, good toughness and 1.沉降s急骤增大,荷载~沉降(p~s)曲线上有可判定极限承载力的陡降段,且沉降量超过0.04d(d为承压板直径); 2.在某级荷载下,24小时内沉降速率不能达到稳定; 3.本级沉降量大于前一级沉降量的5倍; 当持力层土层坚硬,沉降量很小时,最大加载量不小于设计要求的2倍。 4. D.0.6条 承载力特征值的确定应符合下列规定: 1.当p~s曲线上有比例界限时,取该比例界限所对应的荷载值; 2.满足前三条终止加载条件之一时,其对应的前一级荷载定为极限荷载,当该值小于对应比例界限的荷载值的2倍时,取极限荷载值的一半; 3.不能按上述二款要求确定时,可取s/d=0.01~0.015所对应的荷载值,但其值不应大于最大加载量的一半。 D.0.7条 同一土层参加统计的试验点不应少于三点,当试验实测值的极差不超过平均值的30%时,取此平均值作为该土层的地基承载力特征值fak 。 附录A 复合地基载荷试验要点 A.0.1 本试验要点适用于单桩复合地基载荷试验和多桩复合地基载荷试验。 A.0.2 复合地基载荷试验用于测定承压板下应力主要影响范围内复合土层的承载力和变形参数。复合地基载荷试验承压板应具有足够刚度。单桩复合地基载荷试验的承压板可用圆形或方形,面积为一根桩承担的处理面积;多桩复合地基载荷试验的承压板可用方形或矩形,其尺寸按实际桩数所承担的处理面积确定。桩的中心(或形心)应与承压板中心保持一致,并与荷载作用点相重合。 A.0.3 承压板底面标高应与桩顶设计标高相适应。承压板底面下宜铺设粗砂或中砂垫层,垫层厚度取50,150mm,桩身强度高时宜取大值。试验标高处的试坑长度和宽度,应不小于承压板尺寸的3倍。基准梁的支点应设在试坑之外。 A.0.4 试验前应采取措施,防止试验场地地基土含水量变化或地基土扰动。以免影响试验结果。 A.0.5 加载等级可分为8,12级。最大加载压力不应小于设计要求压力值的2倍。 A.0.6 每加一级荷载前后均应各读记承压板沉降量一次,以后每半个小时读记一次。当一小时内沉降量小于0.1mm时,即可加下一级荷载。 A.0.7 当出现下列现象之一时可终止试验: 1 沉降急剧增大,土被挤出或承压板周围出现明显的隆起; 2 承压板的累计沉降量已大于其宽度或直径的6%; 3 当达不到极限荷载,而最大加载压力已大于设计要求压力值的2倍。 A.0.8 卸载级数可为加载级数的一半,等量进行,每卸一级,间隔半小时,读记回弹量,待卸完全部 yer thform, dense, painted pitch inspection should be no delamination, cavitation, homogeneity of asphalt coating, brushing each la.4 pipelines asphalt, fiber glass fabric corrosion, external appearance should never show surrounded by glass fiber cloth uni7.8.2 es, flow marks, scum, paint particles and visible brush marks. 7.8.2.3 interlayer should be tight and without stratification.d have at least a primer (red paint) and finish. 7.8.2.2 paint appearance color uniform, without paint, rust, flaking, wrinklwall temperature of environment temperature ? 40 ? c. 7.8.2 paint 7.8.2.l paint of equipment and pipelines shoul-ayer (hot) = shellping and other equipment shall have sufficient expansion gap in hot situations. 7.8.1.8 metal temperature of the insulating lor pi dirt and corrosion treatment should be carried out, install the bridge ... 7.8.1.7 piping and piping, equipment and equipmented connections are not allowed. 7.7.5 service sleeve should have a good grounding. 7.7.6 cable trays installation, burrs and , weldd piping application root production, growing where interface is required, only straight pipe, only the wire port connectionstube in. 7.7.3 ellipticity of a bent tube, pipe diameter ? 60mm, not >8%, diameter >760mm, not >6%. 7.7.4 making cables burief the hout burrs, smooth. 7.7.2 pipe does not allow bending, bending the bend radius should be ? 4 times times the outer diameter oounding. 7.7 quality standard 7.7.l cables through the cable embedded tube making use of galvanized steel pipe, tube ends witre binding order, reliable grshould be tightened, no loose, Terminal Board wiring should be one on each side, no more than two. J, shielded wire, spare wind processing require plate high strength, good toughness andtic perception of quality standards. Construction technology requirements are as follows: template template Panel selection ato display strength and aesthefaced concrete is a concrete surface without any decoration, structure appearance quality of concrete structure that is able -ickness in accordance with design requirements. Standard 7.9 7.9 structure placement process. 1 fair62 荷载后间隔三小时读记总回弹量。 A.0.9 复合地基承载力特征值的确定: 1 当压力一沉降曲线上极限荷载能确定,而其值不小于对应比例界限的2倍时,可取比例界限;当其值小于对应比例界限的2倍时,可取极限荷载的一半; 2 当压力一沉降曲线是平缓的光滑曲线时,可按相对变形值确定; 1)对砂石桩、振冲桩复合地基或强夯置换墩:当以粘性土为主的地基,可取s/b或s/d等于0.015所对应的压力(s为载荷试验承压板的沉降量;b和d分别为承压板宽度和直径,当其值大于2m时,按2m计算);当以粉土或砂土为主的地基,可取s/b或s/d等于0.01所对应的压力。 2)对土挤密桩、石灰桩或柱锤冲扩桩复合地基,可取s/b或s/d等于0.012所对应的压力。对灰土挤密桩复合地基,可取s/b或s/d等于0.008所对应的压力。 3)对水泥粉煤灰碎石桩或夯实水泥土桩复合地基,当以卵石、圆砾、密实粗中砂为主的地基,可取s/b或s/d等于0.008所对应的压力;当以粘性土、粉土为主的地基,可取s/b或s/d等于0.01所对应的压力。 4)对水泥土搅拌桩或旋喷桩复合地基,可取s/b或s/d等于0.006所对应的压力。 5)对有经验的地区,也可按当地经验确定相对变形值。 按相对变形值确定的承载力特征值不应大于最大加载压力的一半。 A.0.10 试验点的数量不应少于3点,当满足其极差不超过平均值的30%时,可取其平均值为复合地基承载力特征值。 4 单桩竖向抗压静载试验 4.1 适 用 范 围 4.1.1 本 方法 快递客服问题件处理详细方法山木方法pdf计算方法pdf华与华方法下载八字理论方法下载 适用于检测单桩的竖向抗压承载力。 4.1.2 当埋设有测量桩身应力、应变、桩底反力的传感器或位移杆时,可测定桩分层侧阻力和端阻力或桩身截面的位移量。 4.1.3 为设计提供依据的试验桩,应加载至破坏;当桩的承载力以桩身强度控制时,可按设计要求的加载量进行。 4.1.4 对工程桩抽样检测时,加载量不应小于设计要求的单桩承载力特征值的2.0倍。 4.2 仪器设备及其安装 4.2.1 试验加载宜采用油压千斤顶。当采用两台及两台以上千斤顶加载时应并联同步工作,且应符合下列规定: lass fabric corrosion, external appearance should never show surrounded by glass fiber cloth uniform, dense, painted pitch ines and visible brush marks. 7.8.2.3 interlayer should be tight and without stratification. 7.8.2.4 pipelines asphalt, fiber grticlpaint) and finish. 7.8.2.2 paint appearance color uniform, without paint, rust, flaking, wrinkles, flow marks, scum, paint paof environment temperature ? 40 ? c. 7.8.2 paint 7.8.2.l paint of equipment and pipelines should have at least a primer (red wall temperature-have sufficient expansion gap in hot situations. 7.8.1.8 metal temperature of the insulating layer (hot) = shell be carried out, install the bridge ... 7.8.1.7 piping and piping, equipment and equipment or piping and other equipment shall shouldd. 7.7.5 service sleeve should have a good grounding. 7.7.6 cable trays installation, burrs and dirt and corrosion treatment n, growing where interface is required, only straight pipe, only the wire port connections, welded connections are not alloweuctioa bent tube, pipe diameter ? 60mm, not >8%, diameter >760mm, not >6%. 7.7.4 making cables buried piping application root prodnot allow bending, bending the bend radius should be ? 4 times times the outer diameter of the tube in. 7.7.3 ellipticity of does 7.7.l cables through the cable embedded tube making use of galvanized steel pipe, tube ends without burrs, smooth. 7.7.2 pipe d be one on each side, no more than two. J, shielded wire, spare wire binding order, reliable grounding. 7.7 quality standardshould be tightened, no loose, Terminal Board wiring shoulrength, good toughness andigh stndards. Construction technology requirements are as follows: template template Panel selection and processing require plate h, structure appearance quality of concrete structure that is able to display strength and aesthetic perception of quality stafaced concrete is a concrete surface without any decoration-sign requirements. Standard 7.9 7.9 structure placement process. 1 fairon should be no delamination, cavitation, homogeneity of asphalt coating, brushing each layer thickness in accordance with despecti63 1 采用的千斤顶型号、规格应相同。 2 千斤顶的合力中心应与桩轴线重合。 4.2.2 加载反力装置可根据现场条件选择锚桩横梁反力装置、压重平台反力装置、锚桩压重联合反力装置、地锚反力装置,并应符合下列规定: 1 加载反力装置能提供的反力不得小于最大加载量的1.2倍。 2 应对加载反力装置的全部构件进行强度和变形验算。 3 应对锚桩抗拔力(地基土、抗拔钢筋、桩的接头)进行验算;采用工程桩作锚桩时,锚桩数量不应少于4根,并应监测锚桩上拔量。 4 压重宜在检测前一次加足,并均匀稳固地放置于平台上。 5 压重施加于地基的压应力不宜大于地基承载力特征值的1.5倍,有条件时宜利用工程桩作为堆载支点。 4.2.3 荷载测量可用放置在千斤顶上的荷重传感器直接测定;或采用并联于千斤顶油路的压力表或压力传感器测定油压,根据千斤顶率定曲线换算荷载。传感器的测量误差不应大于1%,压力表精度应优于或等于0.4级。试验用千斤顶、油泵、油管在最大加载时的压力不应超过规定工作压力的80%。 4.2.4 沉降测量宜采用位移传感器或大量程百分表,并应符合下列规定: 1 测量误差不大于0.1%FS,分辨力优于或等于0.01mm。 2 直径或边宽大于500mm的桩,应在其两个方向对称安置4个位移测试仪表,直径或边宽小于等于500mm的桩可对称安置2个位移测试仪表。 3 沉降测定平面宜在桩顶200mm以下位置,测点应牢固地固定于桩身。 4 基准梁应具有一定的刚度,梁的一端应固定在基准桩上,另一端应简支于基准桩上。 5 固定和支撑位移计(百分表)的夹具及基准梁应避免气温、振动及其他外界因素的影响。 4.2.5 试桩、锚桩(压重平台支墩边)和基准桩之间的中心距离应符合表4.2.5规定。 试桩、锚桩(或压重平台支墩边)和基准桩之间的中心距离 表4.2.5 距 试桩中心与锚桩中心(或压重基准桩中心与锚桩中心(或压重平试桩中心与基准桩中心 离 平台支墩边) 台支墩边) 反力装置 锚桩横梁 ?4(3)D且,2.0m ?4(3)D且,2.0m ?4(3)D且,2.0m 压重平台 ?4D且,2.0m ?4(3)D且,2.0m ?4D且,2.0m 地锚装置 ?4D且,2.0m ?4(3)D且,2.0m ?4D且,2.0m 注:1 D为试桩、锚桩或地锚的设计直径或边宽,取其较大者。 2 如试桩或锚桩为扩底桩或多支盘桩时,试桩与锚桩的中心距尚不应小于2倍扩大端直径。 3 括号内数值可用于工程桩验收检测时多排桩基础设计桩中心距离小于4D的情况。 4 软土场地堆载重量较大时,宜增加支墩边与基准桩中心和试桩中心之间的距离,并在试验过程中观测基准桩的竖向位移。 4.2.6 当需要测试桩侧阻力和桩端阻力时,桩身内埋设传感器应按本规范附录A执行。 es, flow marks, scum, paint particles and visible brush marks. 7.8.2.3 interlayer should be tight and without stratification.d have at least a primer (red paint) and finish. 7.8.2.2 paint appearance color uniform, without paint, rust, flaking, wrinklwall temperature of environment temperature ? 40 ? c. 7.8.2 paint 7.8.2.l paint of equipment and pipelines shoul-ayer (hot) = shellping and other equipment shall have sufficient expansion gap in hot situations. 7.8.1.8 metal temperature of the insulating lor pi dirt and corrosion treatment should be carried out, install the bridge ... 7.8.1.7 piping and piping, equipment and equipmented connections are not allowed. 7.7.5 service sleeve should have a good grounding. 7.7.6 cable trays installation, burrs and , weldd piping application root production, growing where interface is required, only straight pipe, only the wire port connectionstube in. 7.7.3 ellipticity of a bent tube, pipe diameter ? 60mm, not >8%, diameter >760mm, not >6%. 7.7.4 making cables burief the hout burrs, smooth. 7.7.2 pipe does not allow bending, bending the bend radius should be ? 4 times times the outer diameter oounding. 7.7 quality standard 7.7.l cables through the cable embedded tube making use of galvanized steel pipe, tube ends witre binding order, reliable grshould be tightened, no loose, Terminal Board wiring should be one on each side, no more than two. J, shielded wire, spare wind processing require plate high strength, good toughness andtic perception of quality standards. Construction technology requirements are as follows: template template Panel selection ato display strength and aesthefaced concrete is a concrete surface without any decoration, structure appearance quality of concrete structure that is able -ickness in accordance with design requirements. Standard 7.9 7.9 structure placement process. 1 fairyer thform, dense, painted pitch inspection should be no delamination, cavitation, homogeneity of asphalt coating, brushing each la.4 pipelines asphalt, fiber glass fabric corrosion, external appearance should never show surrounded by glass fiber cloth uni7.8.2 64 4.3 现 场 检 测 4.3.1 试桩的成桩工艺和质量控制 标准 excel标准偏差excel标准偏差函数exl标准差函数国标检验抽样标准表免费下载红头文件格式标准下载 应与工程桩一致。 4.3.2 桩顶部宜高出试坑底面,试坑底面宜与桩承台底标高一致。混凝土桩头加固可参照本规范附录B执行。 4.3.3 对作为锚桩用的灌注桩和有接头的混凝土预制桩,检测前宜对其桩身完整性进行检测。 4.3.4 试验加卸载方式应符合下列规定: 1 加载应分级进行,采用逐级等量加载;分级荷载宜为最大加载量或预估极限承载力的1/10,其中第一级可取分级荷载的2倍。 2 卸载应分级进行,每级卸载量取加载时分级荷载的2倍,逐级等量卸载。 3 加、卸载时应使荷载传递均匀、连续、无冲击,每级荷载在维持过程中的变化幅度不得超过该级增减量的,10%。 4.3.5 为设计提供依据的竖向抗压静载试验应采用慢速维持荷载法。 4.3.6 慢速维持荷载法试验步骤应符合下列规定: 每级荷载施加后按第5、15、30、45、60min测读桩顶沉降量,以后每隔30min测读一次。 1 2 试桩沉降相对稳定标准:每一小时内的桩顶沉降量不超过0.1mm,并连续出现两次(从每级荷载施加后第30min开始,由三次或三次以上每30min的沉降观测值计算)。 3 当桩顶沉降速率达到相对稳定标准时,再施加下一级荷载。 4 卸载时,每级荷载维持1h,按第5、15、30、60min测读桩顶沉降量;卸载至零后,应测读桩顶残余沉降量,维持时间为3h,测读时间为5、15、30min,以后每隔30min测读一次。 4.3.7 施工后的工程桩验收检测宜采用慢速维持荷载法。当有成熟的地区经验时,也可采用快速维持荷载法。 快速维持荷载法的每级荷载维持时间不得少于1h。当桩顶沉降尚未明显收敛时,不得施加下一级荷载。 4.3.8 当出现下列情况之一时,可终止加载: 1 某级荷载作用下,桩顶沉降量大于前一级荷载作用下沉降量的5倍。 注:当桩顶沉降能稳定且总沉降量小于40mm时,宜加载至桩顶总沉降量超过40mm。 2 某级荷载作用下,桩顶沉降量大于前一级荷载作用下沉降量的2倍,且经24h尚未达到稳定标准。 3 已达加载反力装置的最大加载量。 4 已达到设计要求的最大加载量。 5 当工程桩作锚桩时,锚桩上拔量已达到允许值。 sign requirements. Standard 7.9 7.9 structure placement process. 1 fairon should be no delamination, cavitation, homogeneity of asphalt coating, brushing each layer thickness in accordance with despectilass fabric corrosion, external appearance should never show surrounded by glass fiber cloth uniform, dense, painted pitch ines and visible brush marks. 7.8.2.3 interlayer should be tight and without stratification. 7.8.2.4 pipelines asphalt, fiber grticlpaint) and finish. 7.8.2.2 paint appearance color uniform, without paint, rust, flaking, wrinkles, flow marks, scum, paint paof environment temperature ? 40 ? c. 7.8.2 paint 7.8.2.l paint of equipment and pipelines should have at least a primer (red wall temperature-have sufficient expansion gap in hot situations. 7.8.1.8 metal temperature of the insulating layer (hot) = shell be carried out, install the bridge ... 7.8.1.7 piping and piping, equipment and equipment or piping and other equipment shall shouldd. 7.7.5 service sleeve should have a good grounding. 7.7.6 cable trays installation, burrs and dirt and corrosion treatment n, growing where interface is required, only straight pipe, only the wire port connections, welded connections are not alloweuctioa bent tube, pipe diameter ? 60mm, not >8%, diameter >760mm, not >6%. 7.7.4 making cables buried piping application root prodnot allow bending, bending the bend radius should be ? 4 times times the outer diameter of the tube in. 7.7.3 ellipticity of does 7.7.l cables through the cable embedded tube making use of galvanized steel pipe, tube ends without burrs, smooth. 7.7.2 pipe d be one on each side, no more than two. J, shielded wire, spare wire binding order, reliable grounding. 7.7 quality standardshould be tightened, no loose, Terminal Board wiring shoulrength, good toughness andigh stndards. Construction technology requirements are as follows: template template Panel selection and processing require plate h, structure appearance quality of concrete structure that is able to display strength and aesthetic perception of quality stafaced concrete is a concrete surface without any decoration-65 6 当荷载–沉降曲线呈缓变型时,可加载至桩顶总沉降量60,80mm;在特殊情况下,可根据具体要求加载至桩顶累计沉降量超过80mm。 4.3.9 检测数据宜按本规范附录C附表C.0.1的格式 记录 混凝土 养护记录下载土方回填监理旁站记录免费下载集备记录下载集备记录下载集备记录下载 。 4.3.10 测试桩侧阻力和桩端阻力时,测试数据的测读时间应符合第4.3.6条的规定。 4.4 检测数据分析与判定 4.4.1 检测数据的整理应符合下列规定: 1 确定单桩竖向抗压承载力时,应绘制竖向荷载-沉降(Q-s)、沉降-时间对数(s-lgt)曲线,需要时也可绘制其他辅助分析所需曲线。 2 当进行桩身应力、应变和桩底反力测定时,应整理出有关数据的记录表,并按本规范附录B绘制桩身轴力分布图、计算不同土层的分层侧摩阻力和端阻力值。 4.4.2 单桩竖向抗压极限承载力Q可按下列方法综合分析确定: u 1 根据沉降随荷载变化的特征确定:对于陡降型Q-s曲线,取其发生明显陡降的起始点对应的荷载值。 2 根据沉降随时间变化的特征确定:取s-lgt曲线尾部出现明显向下弯曲的前一级荷载值。 3 出现第4.3.8条第2款情况,取前一级荷载值。 4 对于缓变型Q-s曲线可根据沉降量确定,宜取s=40mm对应的荷载值;当桩长大于40m时,宜考虑桩身弹性压缩量;对直径大于或等于800mm的桩,可取s=0.05D(D为桩端直径)对应的荷载值。 注:当按上述四款判定桩的竖向抗压承载力未达到极限时,桩的竖向抗压极限承载力应取最大试验荷载值。 4.4.3 单桩竖向抗压极限承载力统计值的确定应符合下列规定: 1 参加统计的试桩结果,当满足其极差不超过平均值的30%时,取其平均值为单桩竖向抗压极限承载力。 2 当极差超过平均值的30%时,应分析极差过大的原因,结合工程具体情况综合确定。必要时可增加试桩数量。 3 对桩数为3根或3根以下的柱下承台,或工程桩抽检数量小于3根时,应取低值。 4.4.4 单位工程同一条件下的单桩竖向抗压承载力特征值R应按单桩竖向抗压极限承载力统计值的a 一半取值。 4.4.5 检测报告除应包括本规范第3.5.5条内容外,还应包括: 1 受检桩桩位对应的地质柱状图; 2 受检桩及锚桩的尺寸、材料强度、锚桩数量、配筋情况; 3 加载反力种类,堆载法应指明堆载重量,锚桩法应有反力梁布置平面图; to display strength and aesthefaced concrete is a concrete surface without any decoration, structure appearance quality of concrete structure that is able -ickness in accordance with design requirements. Standard 7.9 7.9 structure placement process. 1 fairyer thform, dense, painted pitch inspection should be no delamination, cavitation, homogeneity of asphalt coating, brushing each la.4 pipelines asphalt, fiber glass fabric corrosion, external appearance should never show surrounded by glass fiber cloth uni7.8.2 es, flow marks, scum, paint particles and visible brush marks. 7.8.2.3 interlayer should be tight and without stratification.d have at least a primer (red paint) and finish. 7.8.2.2 paint appearance color uniform, without paint, rust, flaking, wrinklwall temperature of environment temperature ? 40 ? c. 7.8.2 paint 7.8.2.l paint of equipment and pipelines shoul-ayer (hot) = shellping and other equipment shall have sufficient expansion gap in hot situations. 7.8.1.8 metal temperature of the insulating lor pi dirt and corrosion treatment should be carried out, install the bridge ... 7.8.1.7 piping and piping, equipment and equipmented connections are not allowed. 7.7.5 service sleeve should have a good grounding. 7.7.6 cable trays installation, burrs and , weldd piping application root production, growing where interface is required, only straight pipe, only the wire port connectionstube in. 7.7.3 ellipticity of a bent tube, pipe diameter ? 60mm, not >8%, diameter >760mm, not >6%. 7.7.4 making cables burief the hout burrs, smooth. 7.7.2 pipe does not allow bending, bending the bend radius should be ? 4 times times the outer diameter oounding. 7.7 quality standard 7.7.l cables through the cable embedded tube making use of galvanized steel pipe, tube ends witre binding order, reliable grshould be tightened, no loose, Terminal Board wiring should be one on each side, no more than two. J, shielded wire, spare wind processing require plate high strength, good toughness andtic perception of quality standards. Construction technology requirements are as follows: template template Panel selection a66 4 加卸载方法,荷载分级; 5 第4.4.1条要求绘制的曲线及对应的数据表;与承载力判定有关的曲线及数据; 6 承载力判定依据; 7 当进行分层摩阻力测试时,还应有传感器类型、安装位置,轴力计算方法,各级荷载下桩身轴力变化曲线,各土层的桩侧极限摩阻力和桩端阻力。 -sign requirements. Standard 7.9 7.9 structure placement process. 1 fairon should be no delamination, cavitation, homogeneity of asphalt coating, brushing each layer thickness in accordance with despectilass fabric corrosion, external appearance should never show surrounded by glass fiber cloth uniform, dense, painted pitch ines and visible brush marks. 7.8.2.3 interlayer should be tight and without stratification. 7.8.2.4 pipelines asphalt, fiber grticlpaint) and finish. 7.8.2.2 paint appearance color uniform, without paint, rust, flaking, wrinkles, flow marks, scum, paint paof environment temperature ? 40 ? c. 7.8.2 paint 7.8.2.l paint of equipment and pipelines should have at least a primer (red wall temperature-have sufficient expansion gap in hot situations. 7.8.1.8 metal temperature of the insulating layer (hot) = shell be carried out, install the bridge ... 7.8.1.7 piping and piping, equipment and equipment or piping and other equipment shall shouldd. 7.7.5 service sleeve should have a good grounding. 7.7.6 cable trays installation, burrs and dirt and corrosion treatment n, growing where interface is required, only straight pipe, only the wire port connections, welded connections are not alloweuctioa bent tube, pipe diameter ? 60mm, not >8%, diameter >760mm, not >6%. 7.7.4 making cables buried piping application root prodnot allow bending, bending the bend radius should be ? 4 times times the outer diameter of the tube in. 7.7.3 ellipticity of does 7.7.l cables through the cable embedded tube making use of galvanized steel pipe, tube ends without burrs, smooth. 7.7.2 pipe d be one on each side, no more than two. J, shielded wire, spare wire binding order, reliable grounding. 7.7 quality standardshould be tightened, no loose, Terminal Board wiring shoulrength, good toughness andigh stndards. Construction technology requirements are as follows: template template Panel selection and processing require plate h, structure appearance quality of concrete structure that is able to display strength and aesthetic perception of quality stafaced concrete is a concrete surface without any decoration67 5 单桩竖向抗拔静载试验 5.1 适 用 范 围 5.1.1 本方法适用于检测单桩的竖向抗拔承载力。 5.1.2 当埋设有桩身应力、应变测量传感器时,或桩端埋设有位移测量杆时,可直接测量桩侧抗拔摩阻力,或桩端上拔量。 5.1.3 为设计提供依据的试验桩应加载至桩侧土破坏或桩身材料达到设计强度;对工程桩抽样检测时,可按设计要求确定最大加载量。 5.2 设备仪器及其安装 5.2.1 抗拔桩试验加载装置宜采用油压千斤顶,加载方式应符合本规范第4.2.1条规定。 5.2.2 试验反力装置宜采用反力桩(或工程桩)提供支座反力,也可根据现场情况采用天然地基提供支座反力。反力架系统应具有1.2倍的安全系数并符合下列规定: 1 采用反力桩(或工程桩)提供支座反力时,反力桩顶面应平整并具有一定的强度。 采用天然地基提供反力时,施加于地基的压应力不宜超过地基承载力特征值的1.5倍;反力2 梁的支点重心应与支座中心重合。 5.2.3 荷载测量及其仪器的技术要求应符合本规范第4.2.3条的规定。 5.2.4 桩顶上拔量测量及其仪器的技术要求应符合本规范4.2.4条的有关规定。 注:桩顶上拔量观测点可固定在桩顶面的桩身混凝土上。 5.2.5 试桩、支座和基准桩之间的中心距离应符合表4.2.5的规定。 5.2.6 当需要测试桩侧抗拔摩阻力分布或桩底上拔位移时,桩身内埋设传感器或桩底部位埋设位移杆应按本规范附录A执行。 5.3 现 场 检 测 5.3.1 对混凝土灌注桩、有接头的预制桩,宜在拔桩试验前采用低应变法检测受检桩的桩身完整性。为设计提供依据的抗拔灌注桩施工时应进行成孔质量检测,发现桩身中、下部位有明显扩径的桩不宜作为抗拔试验桩;对有接头的预制桩,应验算接头强度。 5.3.2 单桩竖向抗拔静载试验宜采用慢速维持荷载法。需要时,也可采用多循环加、卸载方法。慢速维持荷载法的加卸载分级、试验方法及稳定标准应按本规范第4.3.4条和4.3.6条有关规定执行,并仔细观察桩身混凝土开裂情况。 5.3.3 当出现下列情况之一时,可终止加载: 1 在某级荷载作用下,桩顶上拔量大于前一级上拔荷载作用下的上拔量5倍。 yer thform, dense, painted pitch inspection should be no delamination, cavitation, homogeneity of asphalt coating, brushing each la.4 pipelines asphalt, fiber glass fabric corrosion, external appearance should never show surrounded by glass fiber cloth uni7.8.2 es, flow marks, scum, paint particles and visible brush marks. 7.8.2.3 interlayer should be tight and without stratification.d have at least a primer (red paint) and finish. 7.8.2.2 paint appearance color uniform, without paint, rust, flaking, wrinklwall temperature of environment temperature ? 40 ? c. 7.8.2 paint 7.8.2.l paint of equipment and pipelines shoul-ayer (hot) = shellping and other equipment shall have sufficient expansion gap in hot situations. 7.8.1.8 metal temperature of the insulating lor pi dirt and corrosion treatment should be carried out, install the bridge ... 7.8.1.7 piping and piping, equipment and equipmented connections are not allowed. 7.7.5 service sleeve should have a good grounding. 7.7.6 cable trays installation, burrs and , weldd piping application root production, growing where interface is required, only straight pipe, only the wire port connectionstube in. 7.7.3 ellipticity of a bent tube, pipe diameter ? 60mm, not >8%, diameter >760mm, not >6%. 7.7.4 making cables burief the hout burrs, smooth. 7.7.2 pipe does not allow bending, bending the bend radius should be ? 4 times times the outer diameter oounding. 7.7 quality standard 7.7.l cables through the cable embedded tube making use of galvanized steel pipe, tube ends witre binding order, reliable grshould be tightened, no loose, Terminal Board wiring should be one on each side, no more than two. J, shielded wire, spare wind processing require plate high strength, good toughness andtic perception of quality standards. Construction technology requirements are as follows: template template Panel selection ato display strength and aesthefaced concrete is a concrete surface without any decoration, structure appearance quality of concrete structure that is able -ickness in accordance with design requirements. Standard 7.9 7.9 structure placement process. 1 fair68 2 按桩顶上拔量控制,当累计桩顶上拔量超过100mm时。 3 按钢筋抗拉强度控制,桩顶上拔荷载达到钢筋抗拉强度的0.9倍。 4 对于验收抽样检测的工程桩,达到设计要求的最大上拔荷载值。 5.3.4 检测数据可参照本规范附录C附表C.0.1的格式记录。 5.3.5 测试桩侧抗拔摩阻力或桩底上拔位移时,测试数据的测读时间应符合本规范第4.3.6条的规定。 5.4 检测数据的分析与判定 -δ)和δ与时间t之间的曲线(δ-lgt曲5.4.1 绘制上拔荷载U与桩顶上拔量δ之间的关系曲线(U 线)。 5.4.2 单桩竖向抗拔极限承载力可按下列方法综合判定: 1 根据上拔量随荷载变化的特征确定:对陡变型U-δ曲线,取陡升起始点对应的荷载值; 2 根据上拔量随时间变化的特征确定:取δ-lgt曲线斜率明显变陡或曲线尾部明显弯曲的前一级荷载值。 3 当在某级荷载下抗拔钢筋断裂时,取其前一级荷载值。 5.4.3 单桩竖向抗拔极限承载力统计值的确定应符合本规范第4.4.3条的规定。 5.4.4 当作为验收抽样检测的受检桩在最大上拔荷载作用下,未出现第5.4.2条所列三款情况时,应按设计要求综合判定。 5.4.5 单位工程同一条件下的单桩竖向抗拔承载力特征值应按单桩竖向抗拔极限承载力统计值的一半取值。 注:当工程桩不允许带裂缝工作时,取桩身开裂的前一级荷载作为单桩竖向抗拔承载力特征值,并与按极限荷载一半取值确定的承载 力特征值相比取小值。 5.4.6 检测报告除应包括本规范第3.5.5条内容外,还应包括: 1 受检桩桩位对应的地质柱状图; 2 受检桩尺寸(灌注桩宜标明孔径曲线)及配筋情况; 3 加卸载方法,荷载分级; 4 第5.4.1条要求绘制的曲线及对应的数据表; 5 承载力判定依据; 6 当进行抗拔摩阻力检测时,应有传感器类型、安装位置、轴力计算方法,各级荷载下桩身轴力变化曲线,各土层中的抗拔极限摩阻力。 rticlpaint) and finish. 7.8.2.2 paint appearance color uniform, without paint, rust, flaking, wrinkles, flow marks, scum, paint paof environment temperature ? 40 ? c. 7.8.2 paint 7.8.2.l paint of equipment and pipelines should have at least a primer (red wall temperature-have sufficient expansion gap in hot situations. 7.8.1.8 metal temperature of the insulating layer (hot) = shell be carried out, install the bridge ... 7.8.1.7 piping and piping, equipment and equipment or piping and other equipment shall shouldd. 7.7.5 service sleeve should have a good grounding. 7.7.6 cable trays installation, burrs and dirt and corrosion treatment n, growing where interface is required, only straight pipe, only the wire port connections, welded connections are not alloweuctioa bent tube, pipe diameter ? 60mm, not >8%, diameter >760mm, not >6%. 7.7.4 making cables buried piping application root prodnot allow bending, bending the bend radius should be ? 4 times times the outer diameter of the tube in. 7.7.3 ellipticity of does 7.7.l cables through the cable embedded tube making use of galvanized steel pipe, tube ends without burrs, smooth. 7.7.2 pipe d be one on each side, no more than two. J, shielded wire, spare wire binding order, reliable grounding. 7.7 quality standardshould be tightened, no loose, Terminal Board wiring shoulrength, good toughness andigh stndards. Construction technology requirements are as follows: template template Panel selection and processing require plate h, structure appearance quality of concrete structure that is able to display strength and aesthetic perception of quality stafaced concrete is a concrete surface without any decoration-sign requirements. Standard 7.9 7.9 structure placement process. 1 fairon should be no delamination, cavitation, homogeneity of asphalt coating, brushing each layer thickness in accordance with despectilass fabric corrosion, external appearance should never show surrounded by glass fiber cloth uniform, dense, painted pitch ines and visible brush marks. 7.8.2.3 interlayer should be tight and without stratification. 7.8.2.4 pipelines asphalt, fiber g69 6 单桩水平静载试验 6.1 适 用 范 围 6.1.1 本方法适用于桩顶自由时的单桩水平静载试验;其他形式的水平静载试验可参照使用。 6.1.2 本方法适用于检测单桩的水平承载力,推定地基土抗力系数的比例系数。 6.1.3 当埋设有桩身应变测量传感器时,可测量相应水平荷载作用下的桩身应力,并由此计算桩身弯矩。 6.1.4 为设计提供依据的试验桩宜加载至桩顶出现较大水平位移或桩身结构破坏;对工程桩抽样检测,可按设计要求的水平位移允许值控制加载。 6.2 仪器设备及其安装 6.2.1 水平推力加载装置宜采用油压千斤顶,加载能力不得小于最大试验荷载的1.2倍。 6.2.2 水平推力的反力可由相邻桩提供;当专门设置反力结构时,其承载能力和刚度应大于试验桩的1.2倍。 6.2.3 荷载测量及其仪器的技术要求应符合本规范第4.2.3条的规定;水平力作用点宜与实际工程的桩基承台底面标高一致;千斤顶和试验桩接触处应安置球形支座,千斤顶作用力应水平通过桩身轴线;千斤顶与试桩的接触处宜适当补强。 6.2.4 桩的水平位移测量及其仪器的技术要求应符合本规范第4.2.4条的有关规定。在水平力作用平面的受检桩两侧应对称安装两个位移计;当需要测量桩顶转角时,尚应在水平力作用平面以上50cm的受检桩两侧对称安装两个位移计。 6.2.5 位移测量的基准点设置不应受试验和其他因素的影响,基准点应设置在与作用力方向垂直且与位移方向相反的试桩侧面,基准点与试桩净距不应小于1倍桩径。 6.2.6 测量桩身应力或应变时,各测试断面的测量传感器应沿受力方向对称布置在远离中性轴的受拉和受压主筋上;埋设传感器的纵剖面与受力方向之间的夹角不得大于10?。在地面下10倍桩径(桩宽)的主要受力部分应加密测试断面,断面间距不宜超过1倍桩径;超过此深度,测试断面间距可适当加大。桩身内埋设传感器应按本规范附录A执行。 6.3 现 场 检 测 paint) and finish. 7.8.2.2 paint appearance color uniform, without paint, rust, flaking, wrinkles, flow marks, scum, paint paof environment temperature ? 40 ? c. 7.8.2 paint 7.8.2.l paint of equipment and pipelines should have at least a primer (red wall temperature-have sufficient expansion gap in hot situations. 7.8.1.8 metal temperature of the insulating layer (hot) = shell be carried out, install the bridge ... 7.8.1.7 piping and piping, equipment and equipment or piping and other equipment shall shouldd. 7.7.5 service sleeve should have a good grounding. 7.7.6 cable trays installation, burrs and dirt and corrosion treatment n, growing where interface is required, only straight pipe, only the wire port connections, welded connections are not alloweuctioa bent tube, pipe diameter ? 60mm, not >8%, diameter >760mm, not >6%. 7.7.4 making cables buried piping application root prodnot allow bending, bending the bend radius should be ? 4 times times the outer diameter of the tube in. 7.7.3 ellipticity of does 7.7.l cables through the cable embedded tube making use of galvanized steel pipe, tube ends without burrs, smooth. 7.7.2 pipe d be one on each side, no more than two. J, shielded wire, spare wire binding order, reliable grounding. 7.7 quality standardshould be tightened, no loose, Terminal Board wiring shoulrength, good toughness andigh stndards. Construction technology requirements are as follows: template template Panel selection and processing require plate h, structure appearance quality of concrete structure that is able to display strength and aesthetic perception of quality stafaced concrete is a concrete surface without any decoration-sign requirements. Standard 7.9 7.9 structure placement process. 1 fairon should be no delamination, cavitation, homogeneity of asphalt coating, brushing each layer thickness in accordance with despectilass fabric corrosion, external appearance should never show surrounded by glass fiber cloth uniform, dense, painted pitch ines and visible brush marks. 7.8.2.3 interlayer should be tight and without stratification. 7.8.2.4 pipelines asphalt, fiber grticl61 6.3.1 加载方法宜根据工程桩实际受力特性选用单向多循环加载法或本规范第4章规定的慢速维持荷载法,也可按设计要求采用其他加载方法。需要测量桩身应力或应变的试桩宜采用维持荷载法。 6.3.2 试验加卸载方式和水平位移测量应符合下列规定: 1 单向多循环加载法的分级荷载应小于预估水平极限承载力或最大试验荷载的1/10;每级荷载施加后,恒载4min后可测读水平位移,然后卸载至零,停2min测读残余水平位移,至此完成一个加卸载循环。如此循环5次,完成一级荷载的位移观测。试验不得中间停顿。 2 慢速维持荷载法的加卸载分级、试验方法及稳定标准应按本规范第4.3.4条和4.3.6条有关规定执行。 6.3.3 当出现下列情况之一时,可终止加载: 1 桩身折断; 2 水平位移超过30,40mm(软土取40mm); 3 水平位移达到设计要求的水平位移允许值。 6.3.4 检测数据可按本规范附录C附表C.0.2的格式记录。 6.3.5 测量桩身应力或应变时,测试数据的测读应与水平位移测量同步。 6.4 检测数据分析与判定 6.4.1 检测数据应按下列要求整理: 1 采用单向多循环加载法时应绘制水平力-时间-作用点位移(H-t-Y)关系曲线和水平力-位移0 梯度(H-ΔY/ΔH)关系曲线。 0 2 采用慢速维持荷载法时应绘制水平力-力作用点位移(H-Y)关系曲线、水平力-位移梯度0 (H-ΔY/ΔH)关系曲线、力作用点位移-时间对数(Y-lgt)关系曲线和水平力-力作用点位移双对数00 (lgH-lgY)关系曲线。 0 3 绘制水平力、水平力作用点水平位移-地基土水平抗力系数的比例系数的关系曲线(H-m、Y,m)。 0 当桩顶自由且水平力作用位置位于地面处时,m值可按下列公式确定: 53,,,,Hym, (6.4.1-1) 5233bY(EI)00 15mb,,0,, (6.4.1-2) ,,EI,, wall temperature of environment temperature ? 40 ? c. 7.8.2 paint 7.8.2.l paint of equipment and pipelines shoul-ayer (hot) = shellping and other equipment shall have sufficient expansion gap in hot situations. 7.8.1.8 metal temperature of the insulating lor pi dirt and corrosion treatment should be carried out, install the bridge ... 7.8.1.7 piping and piping, equipment and equipmented connections are not allowed. 7.7.5 service sleeve should have a good grounding. 7.7.6 cable trays installation, burrs and , weldd piping application root production, growing where interface is required, only straight pipe, only the wire port connectionstube in. 7.7.3 ellipticity of a bent tube, pipe diameter ? 60mm, not >8%, diameter >760mm, not >6%. 7.7.4 making cables burief the hout burrs, smooth. 7.7.2 pipe does not allow bending, bending the bend radius should be ? 4 times times the outer diameter oounding. 7.7 quality standard 7.7.l cables through the cable embedded tube making use of galvanized steel pipe, tube ends witre binding order, reliable grshould be tightened, no loose, Terminal Board wiring should be one on each side, no more than two. J, shielded wire, spare wind processing require plate high strength, good toughness andtic perception of quality standards. Construction technology requirements are as follows: template template Panel selection ato display strength and aesthefaced concrete is a concrete surface without any decoration, structure appearance quality of concrete structure that is able -ickness in accordance with design requirements. Standard 7.9 7.9 structure placement process. 1 fairyer thform, dense, painted pitch inspection should be no delamination, cavitation, homogeneity of asphalt coating, brushing each la.4 pipelines asphalt, fiber glass fabric corrosion, external appearance should never show surrounded by glass fiber cloth uni7.8.2 es, flow marks, scum, paint particles and visible brush marks. 7.8.2.3 interlayer should be tight and without stratification.d have at least a primer (red paint) and finish. 7.8.2.2 paint appearance color uniform, without paint, rust, flaking, wrinkl62 4); 式中 m——地基土水平土抗力系数的比例系数(kN/m –1 α——桩的水平变形系数(m); ν——桩顶水平位移系数,由式(6.4.1-2)试算α,当αh?4.0时(h为桩的入土深度),其值 y 为2.441; H——作用于地面的水平力(kN); Y——水平力作用点的水平位移(m); 0 2EI——桩身抗弯刚度(kN?m);其中E为桩身材料弹性模量,I为桩身换算截面惯性矩; b——桩身计算宽度(m);对于圆形桩:当桩径D?1m时,b=0.9(1.5D+0.5); 00 当桩径D,1m时,b=0.9(D+1)。对于矩形桩:当边宽B?1m时,b=1.5B+0.5;当边00 宽B,1m时,b=B+1。 0 6.4.2 对埋设有应力或应变测量传感器的试验应绘制下列曲线,并列表给出相应的数据: 1 各级水平力作用下的桩身弯矩分布图; 2 水平力-最大弯矩截面钢筋拉应力(H-ζ)曲线。 s 6.4.3 单桩的水平临界荷载可按下列方法综合确定: 1 取单向多循环加载法时的HtY0曲线或慢速维持荷载法时的H-Y曲线出现拐点的前一级水--0 平荷载值。 2 取H-ΔY0/ΔH曲线或lgH-lgY曲线上第一拐点对应的水平荷载值。 0 3 取H-ζ曲线第一拐点对应的水平荷载值。 s 6.4.4 单桩的水平极限承载力可根据下列方法综合确定: 1 取单向多循环加载法时的H-t-Y0曲线或慢速维持荷载法时的H-Y0曲线产生明显陡降的起始点对应的水平荷载值。 2 取慢速维持荷载法时的Y-lgt曲线尾部出现明显弯曲的前一级水平荷载值。 0 3 取H-ΔY/ΔH曲线或lgH-lgY曲线上第二拐点对应的水平荷载值。 00 4 取桩身折断或受拉钢筋屈服时的前一级水平荷载值。 6.4.5 单桩水平极限承载力和水平临界荷载统计值的确定应符合本规范第4.4.3条的规定。 6.4.6 单位工程同一条件下的单桩水平承载力特征值的确定应符合下列规定: 1 当水平承载力按桩身强度控制时,取水平临界荷载统计值为单桩水平承载力特征值。 2 当桩受长期水平荷载作用且桩不允许开裂时,取水平临界荷载统计值的0.8倍为单桩水平承载力特征值。。 6.4.7 除本规范第6.4.6条规定外,当水平承载力按设计要求的水平允许位移控制时,可取设计要求的水平允许位移对应的水平荷载作为单桩水平承载力特征值,但应满足有关规范抗裂设计的要求。 -have sufficient expansion gap in hot situations. 7.8.1.8 metal temperature of the insulating layer (hot) = shell be carried out, install the bridge ... 7.8.1.7 piping and piping, equipment and equipment or piping and other equipment shall shouldd. 7.7.5 service sleeve should have a good grounding. 7.7.6 cable trays installation, burrs and dirt and corrosion treatment n, growing where interface is required, only straight pipe, only the wire port connections, welded connections are not alloweuctioa bent tube, pipe diameter ? 60mm, not >8%, diameter >760mm, not >6%. 7.7.4 making cables buried piping application root prodnot allow bending, bending the bend radius should be ? 4 times times the outer diameter of the tube in. 7.7.3 ellipticity of does 7.7.l cables through the cable embedded tube making use of galvanized steel pipe, tube ends without burrs, smooth. 7.7.2 pipe d be one on each side, no more than two. J, shielded wire, spare wire binding order, reliable grounding. 7.7 quality standardshould be tightened, no loose, Terminal Board wiring shoulrength, good toughness andigh stndards. Construction technology requirements are as follows: template template Panel selection and processing require plate h, structure appearance quality of concrete structure that is able to display strength and aesthetic perception of quality stafaced concrete is a concrete surface without any decoration-sign requirements. Standard 7.9 7.9 structure placement process. 1 fairon should be no delamination, cavitation, homogeneity of asphalt coating, brushing each layer thickness in accordance with despectilass fabric corrosion, external appearance should never show surrounded by glass fiber cloth uniform, dense, painted pitch ines and visible brush marks. 7.8.2.3 interlayer should be tight and without stratification. 7.8.2.4 pipelines asphalt, fiber grticlpaint) and finish. 7.8.2.2 paint appearance color uniform, without paint, rust, flaking, wrinkles, flow marks, scum, paint paof environment temperature ? 40 ? c. 7.8.2 paint 7.8.2.l paint of equipment and pipelines should have at least a primer (red wall temperature63 6.4.8 检测报告除应包括本规范第3.5.5条内容外,还应包括: 1 受检桩桩位对应的地质柱状图; 2 受检桩的截面尺寸及配筋情况; 3 加卸载方法,荷载分级; 第6.4.1条要求绘制的曲线及对应的数据表; 4 5 承载力判定依据; 6 当进行钢筋应力测试并由此计算桩身弯矩时,应有传感器类型、安装位置、内力计算方法和 第6.4.2条要求绘制的曲线及其对应的数据表。 es, flow marks, scum, paint particles and visible brush marks. 7.8.2.3 interlayer should be tight and without stratification.d have at least a primer (red paint) and finish. 7.8.2.2 paint appearance color uniform, without paint, rust, flaking, wrinklwall temperature of environment temperature ? 40 ? c. 7.8.2 paint 7.8.2.l paint of equipment and pipelines shoul-ayer (hot) = shellping and other equipment shall have sufficient expansion gap in hot situations. 7.8.1.8 metal temperature of the insulating lor pi dirt and corrosion treatment should be carried out, install the bridge ... 7.8.1.7 piping and piping, equipment and equipmented connections are not allowed. 7.7.5 service sleeve should have a good grounding. 7.7.6 cable trays installation, burrs and , weldd piping application root production, growing where interface is required, only straight pipe, only the wire port connectionstube in. 7.7.3 ellipticity of a bent tube, pipe diameter ? 60mm, not >8%, diameter >760mm, not >6%. 7.7.4 making cables burief the hout burrs, smooth. 7.7.2 pipe does not allow bending, bending the bend radius should be ? 4 times times the outer diameter oounding. 7.7 quality standard 7.7.l cables through the cable embedded tube making use of galvanized steel pipe, tube ends witre binding order, reliable grshould be tightened, no loose, Terminal Board wiring should be one on each side, no more than two. J, shielded wire, spare wind processing require plate high strength, good toughness andtic perception of quality standards. Construction technology requirements are as follows: template template Panel selection ato display strength and aesthefaced concrete is a concrete surface without any decoration, structure appearance quality of concrete structure that is able -ickness in accordance with design requirements. Standard 7.9 7.9 structure placement process. 1 fairyer thform, dense, painted pitch inspection should be no delamination, cavitation, homogeneity of asphalt coating, brushing each la.4 pipelines asphalt, fiber glass fabric corrosion, external appearance should never show surrounded by glass fiber cloth uni7.8.264 附录A 桩身内力测试 A.0.1 基桩内力测试适用于混凝土预制桩、钢桩、组合型桩,也可用于桩身断面尺寸基本恒定或已知的混凝土灌注桩。 A.0.2 对竖向抗压静载试验桩,可得到桩侧各土层的分层抗压摩阻力和桩端支承力;对竖向抗拔静荷载试验桩,可得到桩侧土的分层抗拔摩阻力;对水平力试验桩,可求得桩身弯矩分布,最大弯矩位置等;对打入式预制混凝土桩和钢桩,可得到打桩过程中桩身各部位的锤击压应力、锤击拉应力。 A.0.3 基桩内力测试宜采用应变式传感器或钢弦式传感器。根据测试目的及要求,宜按表A.0.3中的传感器技术、环境特性,选择适合的传感器,也可采用滑动测微计。需要检测桩身某断面或桩底位移时,可在需检测断面设置沉降杆。 传感器技术、环境特性一览表 表A.0.3 类 型 钢弦式传感器 应变式传感器 特 性 传感器体积 大 较小 蠕变 较小,适宜于长期观测 较大,需提高制作技术、工艺解决 测量灵敏度 较低 较高 温度变化的影响 温度变化范围较大时需要修正 可以实现温度变化的自补偿 长导线影响 不影响测试结果 需进行长导线电阻影响的修正 自身补偿能力 补偿能力弱 对自身的弯曲、扭曲可以自补偿 对绝缘的要求 要求不高 要求高 动态响应 差 好 A.0.4 传感器设置位置及数量宜符合下列规定: 1 传感器宜放在两种不同性质土层的界面处,以测量桩在不同土层中的分层摩阻力。在地面处(或以上)应设置一个测量断面作为传感器标定断面。传感器埋设断面距桩顶和桩底的距离不应小于1倍桩径。 2 在同一断面处可对称设置2~4个传感器,当桩径较大或试验要求较高时取高值。 A.0.5 应变式传感器可视以下情况采用不同制作方法: 1 对钢桩可采用以下两种方法之一: 1) 将应变计用特殊的粘贴剂直接贴在钢桩的桩身,应变计宜采用标距3~6mm的350Ω胶基 箔式应变计,不得使用纸基应变计。粘贴前应将贴片区表面除锈磨平,用有机溶剂去污清 on should be no delamination, cavitation, homogeneity of asphalt coating, brushing each layer thickness in accordance with despectilass fabric corrosion, external appearance should never show surrounded by glass fiber cloth uniform, dense, painted pitch ines and visible brush marks. 7.8.2.3 interlayer should be tight and without stratification. 7.8.2.4 pipelines asphalt, fiber grticlpaint) and finish. 7.8.2.2 paint appearance color uniform, without paint, rust, flaking, wrinkles, flow marks, scum, paint paof environment temperature ? 40 ? c. 7.8.2 paint 7.8.2.l paint of equipment and pipelines should have at least a primer (red wall temperature-have sufficient expansion gap in hot situations. 7.8.1.8 metal temperature of the insulating layer (hot) = shell be carried out, install the bridge ... 7.8.1.7 piping and piping, equipment and equipment or piping and other equipment shall shouldd. 7.7.5 service sleeve should have a good grounding. 7.7.6 cable trays installation, burrs and dirt and corrosion treatment n, growing where interface is required, only straight pipe, only the wire port connections, welded connections are not alloweuctioa bent tube, pipe diameter ? 60mm, not >8%, diameter >760mm, not >6%. 7.7.4 making cables buried piping application root prodnot allow bending, bending the bend radius should be ? 4 times times the outer diameter of the tube in. 7.7.3 ellipticity of does 7.7.l cables through the cable embedded tube making use of galvanized steel pipe, tube ends without burrs, smooth. 7.7.2 pipe d be one on each side, no more than two. J, shielded wire, spare wire binding order, reliable grounding. 7.7 quality standardshould be tightened, no loose, Terminal Board wiring shoulrength, good toughness andigh stndards. Construction technology requirements are as follows: template template Panel selection and processing require plate h, structure appearance quality of concrete structure that is able to display strength and aesthetic perception of quality stafaced concrete is a concrete surface without any decoration-sign requirements. Standard 7.9 7.9 structure placement process. 1 fair65 洗,待干燥后粘贴应变计。粘贴好的应变计应采取可靠的防水防潮密封防护措施。 2) 将应变式传感器直接固定在测量位置。 2 对混凝土预制桩和灌注桩,应变传感器的制作和埋设可视具体情况采用以下三种方法之一: 1) 在600~1000mm长的钢筋上,轴向、横向粘贴四个(二个)应变计组成全桥(半桥),经 防水绝缘处理后,到材料试验机上进行应力-应变关系标定。标定时的最大拉力宜控制在 钢筋抗拉强度设计值的60%以内,经三次重复标定,应力-应变曲线的线性、滞后和重复 性满足要求后,方可采用。传感器应在浇筑混凝土前按指定位置焊接或绑扎(泥浆护壁灌 注桩应焊接)在主筋上,并满足规范对钢筋锚固长度的要求。固定后带应变计的钢筋不得 弯曲变形或有附加应力产生。 2) 直接将电阻应变计粘贴在桩身指定断面的主筋上,其制作方法及要求同本条第1款钢桩上 粘贴应变计的方法及要求。 3) 将应变砖或埋入式混凝土应变测量传感器按产品使用要求预埋在预制桩的桩身指定位置。 A.0.6 应变式传感器可按全桥或半桥方式制作,宜优先采用全桥方式。传感器的测量片和补偿片应选用同一规格同一批号的产品,按轴向、横向准确地粘贴在钢筋同一断面上。测点的连接应采用屏蔽 ,测电缆,导线的对地绝缘电阻值应在500MΩ以上,使用前应将整卷电缆除两端外全部浸入水中1h量芯线与水的绝缘;电缆屏蔽线应与钢筋绝缘;测量和补偿所用连接电缆的长度和线径应相同。 A.0.7 电阻应变计及其连接电缆均应有可靠的防潮绝缘防护措施;正式试验前电阻应变计及电缆的系统绝缘电阻不应低于200MΩ。 A.0.8 不同材质的电阻应变计粘贴时应使用不同的粘贴剂。在选用电阻应变计、粘贴剂和导线时,应充分考虑试验桩在制作、养护和施工过程中的环境条件。对采用蒸汽养护或高压养护的混凝土预制桩,应选用耐高温的电阻应变计、粘贴剂和导线。 A.0.9 电阻应变测量所用的电阻应变仪宜具有多点自动测量功能,仪器的分辨力应优于或等于1με,并有存储和打印功能。 A.0.10 弦式钢筋计应按主筋直径大小选择。仪器的可测频率范围应大于桩在最大加载时的频率的1.2倍。使用前应对钢筋计逐个标定,得出压力(推力)与频率之间的关系。 A.0.11 带有接长杆弦式钢筋计可焊接在主筋上;不宜采用螺纹连接。 A.0.12 弦式钢筋计通过与之匹配的频率仪进行测量,频率仪的分辨力应优于或等于1Hz。 A.0.13 当同时进行桩身位移测量时,桩身内力和位移测试应同步。 A.0.14 测试数据整理应符合下列规定: 1 采用应变式传感器测量时,按下列公式对实测应变值进行导线电阻修正: r,采用半桥测量时: (A.0.14-1) ,,,(1,)R -ickness in accordance with design requirements. Standard 7.9 7.9 structure placement process. 1 fairyer thform, dense, painted pitch inspection should be no delamination, cavitation, homogeneity of asphalt coating, brushing each la.4 pipelines asphalt, fiber glass fabric corrosion, external appearance should never show surrounded by glass fiber cloth uni7.8.2 es, flow marks, scum, paint particles and visible brush marks. 7.8.2.3 interlayer should be tight and without stratification.d have at least a primer (red paint) and finish. 7.8.2.2 paint appearance color uniform, without paint, rust, flaking, wrinklwall temperature of environment temperature ? 40 ? c. 7.8.2 paint 7.8.2.l paint of equipment and pipelines shoul-ayer (hot) = shellping and other equipment shall have sufficient expansion gap in hot situations. 7.8.1.8 metal temperature of the insulating lor pi dirt and corrosion treatment should be carried out, install the bridge ... 7.8.1.7 piping and piping, equipment and equipmented connections are not allowed. 7.7.5 service sleeve should have a good grounding. 7.7.6 cable trays installation, burrs and , weldd piping application root production, growing where interface is required, only straight pipe, only the wire port connectionstube in. 7.7.3 ellipticity of a bent tube, pipe diameter ? 60mm, not >8%, diameter >760mm, not >6%. 7.7.4 making cables burief the hout burrs, smooth. 7.7.2 pipe does not allow bending, bending the bend radius should be ? 4 times times the outer diameter oounding. 7.7 quality standard 7.7.l cables through the cable embedded tube making use of galvanized steel pipe, tube ends witre binding order, reliable grshould be tightened, no loose, Terminal Board wiring should be one on each side, no more than two. J, shielded wire, spare wind processing require plate high strength, good toughness andtic perception of quality standards. Construction technology requirements are as follows: template template Panel selection ato display strength and aesthefaced concrete is a concrete surface without any decoration, structure appearance quality of concrete structure that is able 66 2r采用全桥测量时: (A.0.14-2) ,,,,(1,)R 式中 ε——修正后的应变值; ′ ε——修正前的应变值; r——导线电阻(Ω); R——应变计电阻(Ω)。 2 采用弦式传感器测量时,将钢筋计实测频率通过率定系数换算成力,再计算成与钢筋计断面 处的混凝土应变相等的钢筋应变量。 3 在数据整理过程中,应将零漂大、变化无规律的测点删除,求出同一断面有效测点的应变平 均值,并按下式计算该断面处桩身轴力: (A.0.14-3) Q,,,E,Aiiii 式中 Q——桩身第i断面处轴力(kN); i ,——第i断面处应变平均值; i E——第i断面处桩身材料弹性模量(kPa),当桩身断面、配筋一致时,宜按标定断面处的应i 力与应变的比值确定; 2A——第i断面处桩身截面面积(m)。 i 4 按每级试验荷载下桩身不同断面处的轴力值制成表格,并绘制轴力分布图。再由桩顶极限荷 载下对应的各断面轴力值计算桩侧土的分层极限摩阻力和极限端阻力: Q,Qii,1q, (A.0.14-4) siu,li Qn,q (A.0.14-5) pA0 式中 q——桩第i断面与i+1断面间侧摩阻力(kPa); si q——桩的端阻力(kPa); p i——桩检测断面顺序号,i=1,2,„„,n,并自桩顶以下从小到大排列; u——桩身周长(m); l——第i断面与第i+1断面之间的桩长(m); i Q——桩端的轴力(kN); n 2A——桩端面积(m)。 0 5 桩身第i断面处的钢筋应力可按下式计算: -sign requirements. Standard 7.9 7.9 structure placement process. 1 fairon should be no delamination, cavitation, homogeneity of asphalt coating, brushing each layer thickness in accordance with despectilass fabric corrosion, external appearance should never show surrounded by glass fiber cloth uniform, dense, painted pitch ines and visible brush marks. 7.8.2.3 interlayer should be tight and without stratification. 7.8.2.4 pipelines asphalt, fiber grticlpaint) and finish. 7.8.2.2 paint appearance color uniform, without paint, rust, flaking, wrinkles, flow marks, scum, paint paof environment temperature ? 40 ? c. 7.8.2 paint 7.8.2.l paint of equipment and pipelines should have at least a primer (red wall temperature-have sufficient expansion gap in hot situations. 7.8.1.8 metal temperature of the insulating layer (hot) = shell be carried out, install the bridge ... 7.8.1.7 piping and piping, equipment and equipment or piping and other equipment shall shouldd. 7.7.5 service sleeve should have a good grounding. 7.7.6 cable trays installation, burrs and dirt and corrosion treatment n, growing where interface is required, only straight pipe, only the wire port connections, welded connections are not alloweuctioa bent tube, pipe diameter ? 60mm, not >8%, diameter >760mm, not >6%. 7.7.4 making cables buried piping application root prodnot allow bending, bending the bend radius should be ? 4 times times the outer diameter of the tube in. 7.7.3 ellipticity of does 7.7.l cables through the cable embedded tube making use of galvanized steel pipe, tube ends without burrs, smooth. 7.7.2 pipe d be one on each side, no more than two. J, shielded wire, spare wire binding order, reliable grounding. 7.7 quality standardshould be tightened, no loose, Terminal Board wiring shoulrength, good toughness andigh stndards. Construction technology requirements are as follows: template template Panel selection and processing require plate h, structure appearance quality of concrete structure that is able to display strength and aesthetic perception of quality stafaced concrete is a concrete surface without any decoration67 ζ,E?ε (A.0.14-6) si ssi 式中 ζ——桩身第i断面处的钢筋应力(kPa); si E——钢筋弹性模量(kPa); s ε——桩身第i断面处的钢筋应变。 si A.0.15 沉降杆宜采用内外管形式:外管固定在桩身,内管下端固定在需测试断面,顶端高出外管100,200mm,并可与固定断面同步位移。 A.0.16 沉降杆应具有一定的刚度;沉降杆外径与外管内径之差不宜小于10mm,沉降杆接头处应光滑。 A.0.17 测量沉降杆位移的检测仪器应符合本规范第4.2.4条的技术要求。数据的测读应与桩顶位移测量同步。 A.0.18 当沉降杆底端固定断面处桩身埋设有内力测试传感器时,可得到该断面处桩身轴力Q和位i移s。 i 条文说明 4 单桩竖向抗压静载试验 4.1 适 用 范 围 4.1.1单桩抗压静载试验是公认的检测基桩竖向抗压承载力最直观、最可靠的传统方法。本规范主要是针对我国建筑工程中惯用的维持荷载法进行了技术规定。根据桩的使用环境、荷载条件及大量工程检测实践,在国内其他行业或国外,尚有循环荷载、等变形速率及终级荷载长时间维持等方法。 4.1.2桩身内力测试按附录A规定的方法执行。 4.1.3本条明确规定为设计提供依据的静载试验应加载至破坏,即试验应进行到能判定单桩极限承载力为止。对于以桩身强度控制承载力的端承型桩,当设计另有规定时,应从其规定。 4.1.4在对工程桩抽样验收检测时,规定了加载量不应小于单桩承载力特征值的2.0倍,以保证足够的安全储备。实际检测中,有时出现这样的情况:3根工程桩静载试验,分十级加载,其中一根桩第十级破坏,另两根桩满足设计要求,按第3.5.3条,单位工程的单桩竖向抗压承载力特征值不满足设计要求。此时若有一根好桩的最大加载量取为单桩承载力特征值的2.2倍,且试验证实竖向抗压承载力不低于单桩承载力特征值的2.2倍,则单位工程的单桩竖向抗压承载力特征值满足设计要求。显然,若抽检的3根桩有代表性,就可避免不必要的工程处理。 form, dense, painted pitch inspection should be no delamination, cavitation, homogeneity of asphalt coating, brushing each la.4 pipelines asphalt, fiber glass fabric corrosion, external appearance should never show surrounded by glass fiber cloth uni7.8.2 es, flow marks, scum, paint particles and visible brush marks. 7.8.2.3 interlayer should be tight and without stratification.d have at least a primer (red paint) and finish. 7.8.2.2 paint appearance color uniform, without paint, rust, flaking, wrinklwall temperature of environment temperature ? 40 ? c. 7.8.2 paint 7.8.2.l paint of equipment and pipelines shoul-ayer (hot) = shellping and other equipment shall have sufficient expansion gap in hot situations. 7.8.1.8 metal temperature of the insulating lor pi dirt and corrosion treatment should be carried out, install the bridge ... 7.8.1.7 piping and piping, equipment and equipmented connections are not allowed. 7.7.5 service sleeve should have a good grounding. 7.7.6 cable trays installation, burrs and , weldd piping application root production, growing where interface is required, only straight pipe, only the wire port connectionstube in. 7.7.3 ellipticity of a bent tube, pipe diameter ? 60mm, not >8%, diameter >760mm, not >6%. 7.7.4 making cables burief the hout burrs, smooth. 7.7.2 pipe does not allow bending, bending the bend radius should be ? 4 times times the outer diameter oounding. 7.7 quality standard 7.7.l cables through the cable embedded tube making use of galvanized steel pipe, tube ends witre binding order, reliable grshould be tightened, no loose, Terminal Board wiring should be one on each side, no more than two. J, shielded wire, spare wind processing require plate high strength, good toughness andtic perception of quality standards. Construction technology requirements are as follows: template template Panel selection ato display strength and aesthefaced concrete is a concrete surface without any decoration, structure appearance quality of concrete structure that is able -ickness in accordance with design requirements. Standard 7.9 7.9 structure placement process. 1 fairyer th68 4.2 仪器设备及其安装 4.2.1为防止加载偏心,千斤顶的合力中心应与反力装置的重心、桩轴线重合,并保证合力方向垂直。 4.2.2加载反力装置的形式在《建筑桩基技术规范》基础上增加了地锚反力装置,对单桩极限承载力较小的摩擦桩可用土锚作反力;对岩面浅的嵌岩桩,可利用岩锚提供反力。 4.2.3用荷重传感器(直接方式)和油压表(间接方式)两种荷载测量方式的区别在于:前者采用荷重传感器测力,不需考虑千斤顶活塞摩擦对出力的影响;后者需通过率定换算千斤顶出力。同型号千斤顶在保养正常状态下,相同油压时的出力相对误差约为1%,2%,非正常时可高达5%。采用传感器测量荷重或油压,容易实现加卸荷与稳压自动化控制,且测量精度较高。采用压力表测定油压时,为保证测量精度,其精度等级应优于或等于0.4级,不得使用1.5级压力表作加载控制。当油路工作压力较高时,有时出现油管爆裂、接头漏油,油泵加压不足造成千斤顶出力受限、压力表线性度变差等情况,所以应选用耐压高、工作压力大和量程大的油管、油泵和压力表。 4.2.4对于机械式大量程(50mm)百分表,《大量程百分表》JJG379规定的1级标准为:全程示值误差和回程误差分别不超过40μm和8μm,相当于满量程测量误差不大于0.1%。沉降测定平面应在千斤顶底座承压板以下的桩身位置,即不得在承压板上或千斤顶上设置沉降观测点,避免因承压板变形导致沉降观测数据失实。基准桩应打入地面以下足够的深度,一般不小于1m。基准梁应一端固定,另一端简支,这是为减少温度变化引起的基准梁挠曲变形。在满足表4.2.5的规定条件下,基准梁不宜过长,并应采取有效遮挡措施,以减少温度变化和刮风下雨的影响,尤其在昼夜温差较大且白天有阳光照射时更应注意。 4.2.5在试桩加卸载过程中,荷载将通过锚桩(地锚)、压重平台支墩传至试桩、基准桩周围地基土并使之变形,随着试桩、基准桩和锚桩(或压重平台支墩)三者间相互距离缩小,土体变形对试桩产生的附加应力和使基准桩产生变位的影响加剧。 1985年,国际土力学与基础工程协会(ISSMFE)根据世界各国对有关静载试验的规定,提出了静载试验的建议方法并指出:试桩中心到锚桩(或压重平台支墩边)和到基准桩各自间的距离应分别“不小于2.5m或3D”,这和我国现行规范规定的“大于等于4D且不小于2.0m”相比更容易满足(小直径桩按3D控制,大直径桩按2.5m控制)。高重建筑物下的大直径桩试验荷载大、桩间净距小(规定最小中心距为3D),往往受设备能力制约,采用锚桩法检测时,三者间的距离有时很难满足“不小于4D” 的要求,加长基准梁又难避免产生显著的气候环境影响。考虑到现场验收试验中的困难,且加载过程中,锚桩上拔对基准桩、试桩的影响小于压重平台对它们的影响,故本规范中对部分间距的规定放宽为“不小于3D”。 关于压重平台支墩力与基准桩和试桩之间的最小间距问 快递公司问题件快递公司问题件货款处理关于圆的周长面积重点题型关于解方程组的题及答案关于南海问题 ,应区别两种情况对待。在场地土较硬时,堆载引起的支墩及其周边地面沉降和试验加载引起的地面回弹均很小。如Ф1200灌注桩采用10 -have sufficient expansion gap in hot situations. 7.8.1.8 metal temperature of the insulating layer (hot) = shell be carried out, install the bridge ... 7.8.1.7 piping and piping, equipment and equipment or piping and other equipment shall shouldd. 7.7.5 service sleeve should have a good grounding. 7.7.6 cable trays installation, burrs and dirt and corrosion treatment n, growing where interface is required, only straight pipe, only the wire port connections, welded connections are not alloweuctioa bent tube, pipe diameter ? 60mm, not >8%, diameter >760mm, not >6%. 7.7.4 making cables buried piping application root prodnot allow bending, bending the bend radius should be ? 4 times times the outer diameter of the tube in. 7.7.3 ellipticity of does 7.7.l cables through the cable embedded tube making use of galvanized steel pipe, tube ends without burrs, smooth. 7.7.2 pipe d be one on each side, no more than two. J, shielded wire, spare wire binding order, reliable grounding. 7.7 quality standardshould be tightened, no loose, Terminal Board wiring shoulrength, good toughness andigh stndards. Construction technology requirements are as follows: template template Panel selection and processing require plate h, structure appearance quality of concrete structure that is able to display strength and aesthetic perception of quality stafaced concrete is a concrete surface without any decoration-sign requirements. Standard 7.9 7.9 structure placement process. 1 fairon should be no delamination, cavitation, homogeneity of asphalt coating, brushing each layer thickness in accordance with despectilass fabric corrosion, external appearance should never show surrounded by glass fiber cloth uniform, dense, painted pitch ines and visible brush marks. 7.8.2.3 interlayer should be tight and without stratification. 7.8.2.4 pipelines asphalt, fiber grticlpaint) and finish. 7.8.2.2 paint appearance color uniform, without paint, rust, flaking, wrinkles, flow marks, scum, paint paof environment temperature ? 40 ? c. 7.8.2 paint 7.8.2.l paint of equipment and pipelines should have at least a primer (red wall temperature69 2×10m平台堆载11550kN,土层自上而下为凝灰岩残积土、强风化和中风化凝灰岩,堆载和试验加载过程中,距支墩边1m、2m处观测到的地面沉降及回弹量几乎为零。但在软土场地,大吨位堆载由于支墩影响范围大而应引起足够的重视。以某一场地Ф500管桩堆载4000kN为例:在距支墩边0.95m、1.95m、2.55m和3.5m设四根基准桩,平台堆载至4000kN时基准桩下沉量分别为13.4mm、6.7mm、3.0mm和0.1mm;试验加载至4000kN时观测点回弹量分别为2.1mm、0.8mm、0.5mm和0.4mm。但也有报导管桩堆载6000kN,支墩产生明显下沉,试验加载至6000kN时,距支墩边2.9m处的观测点回弹近8mm。这里出现两个问题:其一,支墩边距试桩较近时,大吨位堆载地面下沉将产生负摩阻力,特别对摩擦型桩将明显影响其承载力;其二,桩加载(地面卸载)时地基土回弹对基准桩影响。支墩对试桩、基准桩的影响程度与荷载水平及土质条件等有关。对于软土场地超过10000kN的特大吨位堆载(目前国内压重平台法堆载已超过30000kN),为减少对试桩产生附加影响,应考虑对支墩下2,3倍宽影响范围内的地基进行加固;对大吨位堆载支墩出现明显下沉的情况,尚需进一步积累资料和研究其可靠的沉降测量方法,简易的办法是在远离支墩处用水准仪或张紧的钢丝观测基准桩的竖向位移。 4.3 现 场 检 测 4.3.1 本条是为使试桩具有代表性而提出的。 4.3.2为便于沉降测量仪表安装,试桩顶部宜高出试坑地面;为使试验桩受力条件与设计条件相同,试坑地面宜与承台底标高一致。对于工程桩验收检测,当桩身荷载水平较低时,允许采用水泥砂浆将桩顶抹平的简单桩头处理方法。 4.3.3 本条主要是考虑在实际工程桩检测中,因锚桩质量问题而导致试桩失败或中途停顿的情况时有发生,为此建议在试桩前对灌注桩及有接头的混凝土预制桩进行完整性检测,大致确定其能否作锚桩使用。 4.3.4 本条是按我国的传统做法,对维持荷载法进行原则性的规定。 4.3.5慢速维持荷载法是我国公认,且已沿用多年的标准试验方法,也是其他工程桩竖向抗压承载力验收检测方法的唯一比较标准。 .3.6,4.3.7 按4.3.6条第2款,慢速维持荷载法每级荷载持载时间最少为2h。对绝大多数桩基而4 言,为保证上部结构正常使用,控制桩基绝对沉降是第一位重要的,这是地基基础按变形控制设计的基本原则。在工程桩验收检测中,某些行业或地方标准允许采用快速维持荷载法,但未具体规定试验步骤和其他限定条件。1985年ISSMFE根据世界各国的静载试验有关规定,在推荐的试验方法中,建议维持荷载法加载为每小时一级,稳定标准为0.1mm/20min。当桩端嵌入基岩时,个别国家还允许缩短时间;也有些国家为测定桩的蠕变沉降速率建议采用终级荷载长时间维持法。 快速维持荷载法在国内从70年代就开始应用,我国港口工程规范从83年(JTJ2202,83)、上海地 form, dense, painted pitch inspection should be no delamination, cavitation, homogeneity of asphalt coating, brushing each la.4 pipelines asphalt, fiber glass fabric corrosion, external appearance should never show surrounded by glass fiber cloth uni7.8.2 es, flow marks, scum, paint particles and visible brush marks. 7.8.2.3 interlayer should be tight and without stratification.d have at least a primer (red paint) and finish. 7.8.2.2 paint appearance color uniform, without paint, rust, flaking, wrinklwall temperature of environment temperature ? 40 ? c. 7.8.2 paint 7.8.2.l paint of equipment and pipelines shoul-ayer (hot) = shellping and other equipment shall have sufficient expansion gap in hot situations. 7.8.1.8 metal temperature of the insulating lor pi dirt and corrosion treatment should be carried out, install the bridge ... 7.8.1.7 piping and piping, equipment and equipmented connections are not allowed. 7.7.5 service sleeve should have a good grounding. 7.7.6 cable trays installation, burrs and , weldd piping application root production, growing where interface is required, only straight pipe, only the wire port connectionstube in. 7.7.3 ellipticity of a bent tube, pipe diameter ? 60mm, not >8%, diameter >760mm, not >6%. 7.7.4 making cables burief the hout burrs, smooth. 7.7.2 pipe does not allow bending, bending the bend radius should be ? 4 times times the outer diameter oounding. 7.7 quality standard 7.7.l cables through the cable embedded tube making use of galvanized steel pipe, tube ends witre binding order, reliable grshould be tightened, no loose, Terminal Board wiring should be one on each side, no more than two. J, shielded wire, spare wind processing require plate high strength, good toughness andtic perception of quality standards. Construction technology requirements are as follows: template template Panel selection ato display strength and aesthefaced concrete is a concrete surface without any decoration, structure appearance quality of concrete structure that is able -ickness in accordance with design requirements. Standard 7.9 7.9 structure placement process. 1 fairyer th70 基设计规范从89年(DBJ,08,11,89)起就将这一方法列入,与慢速法一起并列为静载试验方法。快速法由于每一级荷载维持时间短(1h),各级荷载下的桩顶沉降相对慢速法要小一些,但相差不大。表2列出了上海市23根摩擦桩慢速维持荷载法试验实测桩顶稳定时的沉降量和1h时沉降量的对比结果。从中可见,在1/2极限荷载点,快速法1h时的桩顶沉降量与慢速法相差很小(0.5mm以内),平均相差0.2mm;在极限荷载点相差要大些,为0.6,6.1mm,平均2.9mm。相对而言,“慢速维持荷载法”的加荷速率比建筑物建造过程中的施工加载速率要快得多,慢速法试桩得到的使用荷载对应的桩顶沉降与建筑物桩基在长期荷载作用下的实际沉降相比,要小几倍到十几倍,所以,规范中的快慢速试桩沉降差异是可以忽略的。 关于快慢速法极限承载力比较,根据上海市统计的71根试验桩资料(桩端在粘性土中47根,在砂土中24根),这些对比是在同一根桩或桩土条件相同的相邻桩上进行的,得出的结果见表3。 稳定时的沉降量s和1h时的沉降量s的对比 表2w1h s与s之差(mm) s?s(%)w1h1hw 荷载点 幅度 平均 幅度 平均 极限荷载 0.57,6.07 71,96 2.89 86 1?2极限荷载 0.01,0.51 95,100 0.20 98 快速法与慢速法极限承载力比较 表 3 桩端土类别 快速法比慢速法极限荷载提高幅度 粘性土 0,9.6%,平均4.5% 砂土 ,2.5%,9.6%,平均2.3% 从中可以看出快速法试验得出的极限承载力较慢速法略高一些,其中桩端在粘性土中平均提高约1/2级荷载,桩端在砂土中平均提高约1/4级荷载。 在我国,如有些软土中的摩擦桩,按慢速法加载,在2倍设计荷载的前几级,就已出现沉降稳定时间逐渐延长,即在2h甚至更长时间内不收敛。此时,采用快速法是不适宜的。而也有很多地方的工程桩验收试验,在每级荷载施加不久,沉降迅速稳定,缩短持载时间不会明显影响试桩结果;且因试验周期的缩短,又可减少昼夜温差等环境影响引起的沉降观测误差。在此,建议快速维持荷载法按下列步骤进行: 、15、30min测读桩顶沉降量,以后每隔15min测读一次。 1 每级荷载施加后维持1h,按第5 2 测读时间累计为1h时,若最后15min时间间隔的桩顶沉降增量与相邻15min时间间隔的桩顶沉降增量相比未明显收敛时,应延长维持荷载时间,直至最后15min的沉降增量小于相邻15min的沉降增量为止。 3 终止加荷条件可按本规范第4.3.8条第1、3、4、5、6款执行。 4 卸载时,每级荷载维持15min,按第5、15min测读桩顶沉降量后,即可卸下一级荷载。卸载 be carried out, install the bridge ... 7.8.1.7 piping and piping, equipment and equipment or piping and other equipment shall shouldd. 7.7.5 service sleeve should have a good grounding. 7.7.6 cable trays installation, burrs and dirt and corrosion treatment n, growing where interface is required, only straight pipe, only the wire port connections, welded connections are not alloweuctioa bent tube, pipe diameter ? 60mm, not >8%, diameter >760mm, not >6%. 7.7.4 making cables buried piping application root prodnot allow bending, bending the bend radius should be ? 4 times times the outer diameter of the tube in. 7.7.3 ellipticity of does 7.7.l cables through the cable embedded tube making use of galvanized steel pipe, tube ends without burrs, smooth. 7.7.2 pipe d be one on each side, no more than two. J, shielded wire, spare wire binding order, reliable grounding. 7.7 quality standardshould be tightened, no loose, Terminal Board wiring shoulrength, good toughness andigh stndards. Construction technology requirements are as follows: template template Panel selection and processing require plate h, structure appearance quality of concrete structure that is able to display strength and aesthetic perception of quality stafaced concrete is a concrete surface without any decoration-sign requirements. Standard 7.9 7.9 structure placement process. 1 fairon should be no delamination, cavitation, homogeneity of asphalt coating, brushing each layer thickness in accordance with despectilass fabric corrosion, external appearance should never show surrounded by glass fiber cloth uniform, dense, painted pitch ines and visible brush marks. 7.8.2.3 interlayer should be tight and without stratification. 7.8.2.4 pipelines asphalt, fiber grticlpaint) and finish. 7.8.2.2 paint appearance color uniform, without paint, rust, flaking, wrinkles, flow marks, scum, paint paof environment temperature ? 40 ? c. 7.8.2 paint 7.8.2.l paint of equipment and pipelines should have at least a primer (red wall temperature-have sufficient expansion gap in hot situations. 7.8.1.8 metal temperature of the insulating layer (hot) = shell 71 至零后,应测读桩顶残余沉降量,维持时间为2h,测读时间为第5、15、30min,以后每隔30min测读一次。 各地在采用快速法时,应总结积累经验,结合当地条件提出适宜的稳定控制标准。 4.3.8 当桩身存在水平整合型缝隙、桩端有沉渣或吊脚时,在较低竖向荷载时常出现本级荷载沉降超过上一级荷载对应沉降5倍的陡降,当缝隙闭合或桩端与硬持力层接触后,随着持载时间或荷载增加,变形梯度逐渐变缓;当桩身强度不足桩被压断时,也会出现陡降,但与前相反,随着沉降增加,荷载不能维持甚至大幅降低。所以,出现陡降后不宜立即卸荷,而应使桩下沉量超过40mm,以大致判断造成陡降的原因。 非嵌岩的长(超长)桩和大直径(扩底)桩的Q,s曲线一般呈缓变型,在桩顶沉降达到40mm时,桩端阻力一般不能发挥。前者由于长细比大、桩身较柔,弹性压缩量大,桩顶沉降较大时,桩端位移还很小;后者虽桩端位移较大,但尚不足以使端阻力充分发挥。因此,放宽桩顶总沉降量控制标准是合理的。 4.4 检测数据分析与判定 4.4.1 除Q-s曲线、s-lgt曲线外,还有s-lgQ曲线。同一工程的一批试桩曲线应按相同的沉降纵座标比例绘制,满刻度沉降值不宜小于40mm,这样可使结果直观、便于比较。 4.4.2 大实践经验表明:当沉降量达到桩径的10%时,才可能出现极限荷载(太沙基和ISSMFE);粘性土中端阻力充分发挥所需的桩端位移为桩径的4%~5%,而砂土中至少达到15%。故本条第4款对缓变型Q-s曲线,按s=0.05D确定直径大于等于800mm桩的极限承载力大体上是保守的;且因为D?800mm时定义为大直径桩,当D=800mm,0.05D,40mm,正好与中、小直径桩的沉降标准衔接。应该注意,世界各国按桩顶总沉降确定极限承载力的规定差别较大,这和各国安全系数的取值大小、特别是上部结构对桩基沉降的要求有关。因此当按本规范建议的按桩顶沉降量确定极限承载力时,尚应考虑上部结构对桩基沉降的具体要求。 4.4.3 本规范单桩竖向抗压承载力的统计按《建筑地基基础设计规范》GB50007的规定执行。也有根据统计承载力标准差大于15%时,采用极限承载力标准值折减系数的修正方法。实际操作中对桩数大于等于4根时,折减系数的计算比较繁琐,且静载检测本身是通过小样本来推断总体。样本容量愈小,可靠度愈低,而影响单桩承载力的因素复杂多变。当一批受检桩中有一根桩承载力过低,若恰好不是偶然原因,则该验收批一旦被接受,就会增加使用方的风险。因此规定级差超过平均值的30%时,首先应分析原因,结合工程实际综合分析判别。例如一组5根试桩的承载力值依次为800、950、1000、1100、1150kN,平均值为1000kN,单桩承载力最低值和最高值的极差为350kN,超过平均值的30%,则不得将最低值800kN去掉将后面4个值取平均,或将最低和最高值都去掉取中间3个值的平均值, yer thform, dense, painted pitch inspection should be no delamination, cavitation, homogeneity of asphalt coating, brushing each la.4 pipelines asphalt, fiber glass fabric corrosion, external appearance should never show surrounded by glass fiber cloth uni7.8.2 es, flow marks, scum, paint particles and visible brush marks. 7.8.2.3 interlayer should be tight and without stratification.d have at least a primer (red paint) and finish. 7.8.2.2 paint appearance color uniform, without paint, rust, flaking, wrinklwall temperature of environment temperature ? 40 ? c. 7.8.2 paint 7.8.2.l paint of equipment and pipelines shoul-ayer (hot) = shellping and other equipment shall have sufficient expansion gap in hot situations. 7.8.1.8 metal temperature of the insulating lor pi dirt and corrosion treatment should be carried out, install the bridge ... 7.8.1.7 piping and piping, equipment and equipmented connections are not allowed. 7.7.5 service sleeve should have a good grounding. 7.7.6 cable trays installation, burrs and , weldd piping application root production, growing where interface is required, only straight pipe, only the wire port connectionstube in. 7.7.3 ellipticity of a bent tube, pipe diameter ? 60mm, not >8%, diameter >760mm, not >6%. 7.7.4 making cables burief the hout burrs, smooth. 7.7.2 pipe does not allow bending, bending the bend radius should be ? 4 times times the outer diameter oounding. 7.7 quality standard 7.7.l cables through the cable embedded tube making use of galvanized steel pipe, tube ends witre binding order, reliable grshould be tightened, no loose, Terminal Board wiring should be one on each side, no more than two. J, shielded wire, spare wind processing require plate high strength, good toughness andtic perception of quality standards. Construction technology requirements are as follows: template template Panel selection ato display strength and aesthefaced concrete is a concrete surface without any decoration, structure appearance quality of concrete structure that is able -ickness in accordance with design requirements. Standard 7.9 7.9 structure placement process. 1 fair72 应查明是否出现桩的质量问题或场地条件变异;若低值承载力出现的原因并非偶然的施工质量造成,则按本例依次去掉高值后取平均,直至满足极差不超过30%的条件。此外,对桩数小于或等于3根的柱下承台、或试桩数量仅为2根时,应采用低值,以确保安全。对于仅通过少量试桩无法判明级差大的原因时,可增加试桩数量。 4.4.4 《建筑地基基础设计规范》GB50007规定的单桩竖向抗压承载力特征值是按单桩竖向抗压极限承载力统计值除以安全系数2得到的,综合反映了桩侧、桩端极限阻力控制承载力特征值的低限要求。 4.4.5 本条规定了检测报告中应包含的一些内容。避免检测报告过于简单,也有利于委托方、设计及检测部门对报告的审查和分析。 have sufficient expansion gap in hot situations. 7.8.1.8 metal temperature of the insulating layer (hot) = shell be carried out, install the bridge ... 7.8.1.7 piping and piping, equipment and equipment or piping and other equipment shall shouldd. 7.7.5 service sleeve should have a good grounding. 7.7.6 cable trays installation, burrs and dirt and corrosion treatment n, growing where interface is required, only straight pipe, only the wire port connections, welded connections are not alloweuctioa bent tube, pipe diameter ? 60mm, not >8%, diameter >760mm, not >6%. 7.7.4 making cables buried piping application root prodnot allow bending, bending the bend radius should be ? 4 times times the outer diameter of the tube in. 7.7.3 ellipticity of does 7.7.l cables through the cable embedded tube making use of galvanized steel pipe, tube ends without burrs, smooth. 7.7.2 pipe d be one on each side, no more than two. J, shielded wire, spare wire binding order, reliable grounding. 7.7 quality standardshould be tightened, no loose, Terminal Board wiring shoulrength, good toughness andigh stndards. Construction technology requirements are as follows: template template Panel selection and processing require plate h, structure appearance quality of concrete structure that is able to display strength and aesthetic perception of quality stafaced concrete is a concrete surface without any decoration-sign requirements. Standard 7.9 7.9 structure placement process. 1 fairon should be no delamination, cavitation, homogeneity of asphalt coating, brushing each layer thickness in accordance with despectilass fabric corrosion, external appearance should never show surrounded by glass fiber cloth uniform, dense, painted pitch ines and visible brush marks. 7.8.2.3 interlayer should be tight and without stratification. 7.8.2.4 pipelines asphalt, fiber grticlpaint) and finish. 7.8.2.2 paint appearance color uniform, without paint, rust, flaking, wrinkles, flow marks, scum, paint paof environment temperature ? 40 ? c. 7.8.2 paint 7.8.2.l paint of equipment and pipelines should have at least a primer (red wall temperature-73 5 单桩竖向抗拔静载试验 5.1 适 用 范 围 5.1.1 单桩竖向抗拔静载试验是检测单桩竖向抗拔承载力最直观、可靠的方法。与本规范中抗压静载试验一样,拔桩试验也是采用了国内外惯用的维持荷载法,并规定应采用慢速维持荷载法。 5.1.2 当需要检测桩侧抗拔极限摩阻力或了解桩底上拔量时,可按本规范附录A中有关方法执行。 5.1.3 当为设计提供依据时,应加载到能判别单桩抗拔极限承载力为止,或加载到桩身材料强度控制值。在对工程桩抽样验收检测时,可按设计要求控制最大上拔荷载,但应有足够的安全储备。 5.2 仪器设备及其安装 5.2.1 本条的要求基本同第4.2.1条。因拔桩试验时千斤顶安放在反力架上面,当采用二台以上千斤顶加载时,应采取一定的安全措施,防止千斤顶倾倒或其他意外事故发生。 .2.2 当采用天然地基作反力时,两边支座处的地基强度应相近,且两边支座与地面的接触面积宜5 相同,避免加载过程中两边沉降不均造成试桩偏心受拉。为保证反力梁的稳定性,应注意反力桩顶面直径(或边长)不小于反力架的梁宽。 5.2.3,5.2.5 这三条基本参照本规范第4.2.3,4.2.5条执行,但应注意以下两点: 1 桩顶上拔量测量平面必须在桩身位置,严禁在混凝土桩的受拉钢筋上设置位移观测点,避免因钢筋变形导致上拔量观测数据失实。 2 在采用天然地基提供支座反力时,拔桩试验加载相当于给支座处地面加载。支座附近的地面也因此会出现不同程度的沉降。荷载越大,这种变形越明显。为防止支座处地基沉降对基准梁的影响,一是应使基准桩与支座、试桩各自之间的间距满足表4.2.5的规定,二是基准桩需打入试坑地面以下一定深度(一般不宜小于1m)。 5.3 现 场 检 测 5.3.1 本条包含以下三个方面内容: 1 在拔桩试验前,对混凝土灌注桩及有接头的预制桩采用低应变法检查桩身质量,目的是防止因试验桩自身质量问题而影响抗拔试验成果。 2 对抗拔试验的钻孔灌注桩在浇注混凝土前进行成孔检测,目的是查明桩身有无明显扩径现象或出现扩大头,因此类桩的抗拔承载力缺乏代表性。特别是扩大头桩及桩身中下部有明显扩径的桩, 7.8.2 es, flow marks, scum, paint particles and visible brush marks. 7.8.2.3 interlayer should be tight and without stratification.d have at least a primer (red paint) and finish. 7.8.2.2 paint appearance color uniform, without paint, rust, flaking, wrinklwall temperature of environment temperature ? 40 ? c. 7.8.2 paint 7.8.2.l paint of equipment and pipelines shoul-ayer (hot) = shellping and other equipment shall have sufficient expansion gap in hot situations. 7.8.1.8 metal temperature of the insulating lor pi dirt and corrosion treatment should be carried out, install the bridge ... 7.8.1.7 piping and piping, equipment and equipmented connections are not allowed. 7.7.5 service sleeve should have a good grounding. 7.7.6 cable trays installation, burrs and , weldd piping application root production, growing where interface is required, only straight pipe, only the wire port connectionstube in. 7.7.3 ellipticity of a bent tube, pipe diameter ? 60mm, not >8%, diameter >760mm, not >6%. 7.7.4 making cables burief the hout burrs, smooth. 7.7.2 pipe does not allow bending, bending the bend radius should be ? 4 times times the outer diameter oounding. 7.7 quality standard 7.7.l cables through the cable embedded tube making use of galvanized steel pipe, tube ends witre binding order, reliable grshould be tightened, no loose, Terminal Board wiring should be one on each side, no more than two. J, shielded wire, spare wind processing require plate high strength, good toughness andtic perception of quality standards. Construction technology requirements are as follows: template template Panel selection ato display strength and aesthefaced concrete is a concrete surface without any decoration, structure appearance quality of concrete structure that is able -ickness in accordance with design requirements. Standard 7.9 7.9 structure placement process. 1 fairyer thform, dense, painted pitch inspection should be no delamination, cavitation, homogeneity of asphalt coating, brushing each la.4 pipelines asphalt, fiber glass fabric corrosion, external appearance should never show surrounded by glass fiber cloth uni74 其抗拔极限承载力远远高于长度和桩径相同的非扩径桩,且相同荷载下的上拔量也有明显差别。 3 对有接头的PHC、PTC和PC管桩应进行接头抗拉强度验算。对电焊接头的管桩除验算其主筋强度外,还要考虑主筋墩头的折减系数以及管节端板偏心受拉时的强度及稳定性。墩头折减系数可按有关规范取0.92,而端板强度的验算则比较复杂,可按经验取一个较为安全的系数。 5.3.2 本条规定拔桩试验应采用慢速维持荷载法,其荷载分级、试验方法及稳定标准均同第4.3.4条和4.3.6条有关规定。 5.3.3 本条规定出现所列四种情况之一时,可终止荷载。但若在较小荷载下出现某级荷载的桩顶上拔量大于前一级荷载下的5倍时,应综合分析原因。若是试验桩,必要时可继续加载,因混凝土桩当桩身出现多条环向裂缝后,其桩顶位移会出现小的突变,而此时并非达到桩侧土的极限抗拔力。 5.4 检测数据分析与判定 5.4.1 拔桩试验与压桩试验一样,一般应绘制U-δ曲线和δ-lgt曲线,但当上述二种曲线难以判别时,也可以辅以δ-lgU曲线或lgU-lgδ曲线,以确定拐点位置。 5.4.2 本条前两款确定的抗拔极限承载力是土的极限抗拔阻力与桩(包括桩向上运动所带动的土体)的自重标准两部分之和。第3款所指的“断裂”,是因钢筋强度不够情况下的断裂。如果因抗拔钢筋受力不均匀,部分钢筋因受力太大而断裂时,应视为该桩试验失效,并进行补充试验。不能将钢筋断裂前一级荷载作为极限荷载。 5.4.4 工程桩验收检测时,混凝土桩抗拔承载力可能受抗裂或钢筋强度制约,而土的抗拔阻力尚未发挥到极限,一般宜取最大荷载或取上拔量控制值对应的荷载作为极限荷载,不能轻易外推。 5.4.5 当按统计的试桩竖向抗拔极限承载力确定单桩竖向抗拔承载力特征值U时,安全系数取为2,a显然只与极限抗菌素拔承载力按土的极限抗拔阻隔力控制的情况对应。有关抗裂控制要求的解释可参见表6.4.6~6.4.7条的条文说明。 6 单桩水平静载试验 6.1 适 用 范 围 6.1.1桩的水平承载力静载试验除了桩顶自由的单桩试验外,还有带承台桩的水平静载试验(考虑承台的底面阻力和侧面抗力,以便充分反映桩基在水平力作用下的实际工作状况)、桩顶不能自由转动的不同约束条件及桩顶施加垂直荷载等试验方法,也有循环荷载的加载方法。这一切都可根据设计的特殊要求给予满足,并参考本方法进行。 wall temperature-have sufficient expansion gap in hot situations. 7.8.1.8 metal temperature of the insulating layer (hot) = shell be carried out, install the bridge ... 7.8.1.7 piping and piping, equipment and equipment or piping and other equipment shall shouldd. 7.7.5 service sleeve should have a good grounding. 7.7.6 cable trays installation, burrs and dirt and corrosion treatment n, growing where interface is required, only straight pipe, only the wire port connections, welded connections are not alloweuctioa bent tube, pipe diameter ? 60mm, not >8%, diameter >760mm, not >6%. 7.7.4 making cables buried piping application root prodnot allow bending, bending the bend radius should be ? 4 times times the outer diameter of the tube in. 7.7.3 ellipticity of does 7.7.l cables through the cable embedded tube making use of galvanized steel pipe, tube ends without burrs, smooth. 7.7.2 pipe d be one on each side, no more than two. J, shielded wire, spare wire binding order, reliable grounding. 7.7 quality standardshould be tightened, no loose, Terminal Board wiring shoulrength, good toughness andigh stndards. Construction technology requirements are as follows: template template Panel selection and processing require plate h, structure appearance quality of concrete structure that is able to display strength and aesthetic perception of quality stafaced concrete is a concrete surface without any decoration-sign requirements. Standard 7.9 7.9 structure placement process. 1 fairon should be no delamination, cavitation, homogeneity of asphalt coating, brushing each layer thickness in accordance with despectilass fabric corrosion, external appearance should never show surrounded by glass fiber cloth uniform, dense, painted pitch ines and visible brush marks. 7.8.2.3 interlayer should be tight and without stratification. 7.8.2.4 pipelines asphalt, fiber grticlpaint) and finish. 7.8.2.2 paint appearance color uniform, without paint, rust, flaking, wrinkles, flow marks, scum, paint paof environment temperature ? 40 ? c. 7.8.2 paint 7.8.2.l paint of equipment and pipelines should have at least a primer (red 75 6.1.2桩的抗弯能力取决于桩和土的力学性能、桩的自由长度、抗弯刚度、桩宽、桩顶约束等因素。试验条件应尽可能和实际工作条件接近,将各种影响降低到最小的程度,使试验成果能尽量反映工程桩的实际情况。通常情况下,试验条件很难做到和工程桩的情况完全一致,此时应通过试验桩测得桩周土的地基反力特性,即地基土的水平抗力系数。它反映了桩在不同深度处桩侧土抗力和水平位移之间的关系,可视为土的固有特性。根据实际工程桩的情况(如不同桩顶约束、不同自由长度),用它确定土抗力大小,进而计算单桩的水平承载力。因此通过试验求得地基土的水平抗力系数具有更实际、更普遍的意义。 6.2 仪器设备及其安装 6.2.3 水平力作用点位置高于基桩承台底标高,试验时在相对承台底面处产生附加弯矩,影响测试结果,也不利于将试验成果根据实际桩顶的约束予以修正。球形支座的作用是在试验过程中,保持作用力的方向始终水平和通过桩轴线,不随桩的倾斜或扭转而改变。 6.2.6 为保证各测试断面的应力最大值及相应弯矩的测量精度,试桩设置时应严格控制测点的纵剖面与力作用方向之间的偏差。对承受水平荷载的桩而言,桩的破坏是由于桩身弯矩引起的结构破坏。因此对中长桩而言,浅层土的性质起了重要作用,在这段范围内的弯矩变化也最大。为找出最大弯矩及其位置,应加密测试断面。 6.3 现 场 检 测 6.3.1 单向多循环加载法,主要是为了模拟实际结构的受力形式。由于结构物承受的实际荷载异常复杂,所以当需考虑长期水平荷载作用影响时,宜采用第4章规定的慢速维持荷载法。由于单向多循环荷载的施加会给内力测试带来不稳定因素,为方便测试,建议采用第4章规定的慢速或快速维持荷载法;此外水平试验桩通常以结构破坏为主,为缩短试验时间,也可采用更短时间的快速维持荷载法。例如《港口工程桩基规范》(桩的水平承载力设计)JTJ254-98规定每级荷载维持20min。 6.3.3 对抗弯性能较差的长桩或中长桩而言,承受水平承载力的桩的破坏特征是桩身强度破坏,即桩身发生折断,此时试验自然终止。本条对终止加荷的水平位移限制要求是根据《建筑桩基技术规范》提出的;在工程桩水平承载力验收检测中,终止加荷条件可按设计要求或规范规定的水平位移允许值控制。 6.4 检测数据分析与判定 6.4.1 本条中的地基土水平土抗力系数随深度增长的比例系数m值的计算公式仅适用于水平力作用 wall temperature of environment temperature ? 40 ? c. 7.8.2 paint 7.8.2.l paint of equipment and pipelines shoul-ayer (hot) = shellping and other equipment shall have sufficient expansion gap in hot situations. 7.8.1.8 metal temperature of the insulating lor pi dirt and corrosion treatment should be carried out, install the bridge ... 7.8.1.7 piping and piping, equipment and equipmented connections are not allowed. 7.7.5 service sleeve should have a good grounding. 7.7.6 cable trays installation, burrs and , weldd piping application root production, growing where interface is required, only straight pipe, only the wire port connectionstube in. 7.7.3 ellipticity of a bent tube, pipe diameter ? 60mm, not >8%, diameter >760mm, not >6%. 7.7.4 making cables burief the hout burrs, smooth. 7.7.2 pipe does not allow bending, bending the bend radius should be ? 4 times times the outer diameter oounding. 7.7 quality standard 7.7.l cables through the cable embedded tube making use of galvanized steel pipe, tube ends witre binding order, reliable grshould be tightened, no loose, Terminal Board wiring should be one on each side, no more than two. J, shielded wire, spare wind processing require plate high strength, good toughness andtic perception of quality standards. Construction technology requirements are as follows: template template Panel selection ato display strength and aesthefaced concrete is a concrete surface without any decoration, structure appearance quality of concrete structure that is able -ickness in accordance with design requirements. Standard 7.9 7.9 structure placement process. 1 fairyer thform, dense, painted pitch inspection should be no delamination, cavitation, homogeneity of asphalt coating, brushing each la.4 pipelines asphalt, fiber glass fabric corrosion, external appearance should never show surrounded by glass fiber cloth uni7.8.2 es, flow marks, scum, paint particles and visible brush marks. 7.8.2.3 interlayer should be tight and without stratification.d have at least a primer (red paint) and finish. 7.8.2.2 paint appearance color uniform, without paint, rust, flaking, wrinkl76 点至试坑地面的桩自由长度为零时的情况。按桩、土相对刚度不同,水平荷载作用下的桩-体系有两种工作状态和破坏机理,一种是“刚性短桩”,因转动或平移而破坏,相当于αh,2.5时的情况;另一种是工程中常见的“弹性长桩”,桩身产生挠曲变形,桩下段嵌固于土中不能转动,即本条中αh?4.0的情况。在2.5?αh,4.0范围内,称为“有限长度的中长桩”。《建筑桩基技术规范》对中长桩的ν变化给出了具体数值(见表3)。因此,在按式(6.4.1-1)计算m值时,应先试算αh值,以确定αhy 是否大于或等于4.0,若在2.5,4.0范围以内,应调整ν值重新计算m值(有些行业标准不考虑)。y 当αh,2.5时,式(6.4.1-1)不适用。 桩顶水平位移系数ν表4y 桩的换算埋深αh 4.0 3.5 3.0 2.8 2.6 2.4 桩顶自由或铰接时的ν值 2.441 2.502 2.727 2.905 3.163 3.526 y 注:当αh,4.0时取αh,4.0。 试验得到的地基土水平抗力系数的比例系数m不是一个常量,而是随地面水平位移及荷载而变化的曲线。 .4.3 对于混凝土长桩或中长桩,随着水平荷载的增加,桩侧土体的塑性区自上而下逐渐开展扩大,6 最大弯矩断面下移,最后形成桩身结构的破坏。所测水平临界荷载H即当桩身产生开裂时所对应的cr 水平荷载。因为只有混凝土桩才会产生开裂,故只有混凝土桩才有临界荷载。 6.4.4 单桩水平极限承载力是对应于桩身折断或桩身钢筋应力达到屈服时的前一级水平荷载。 6.4.6~6.4.7 单桩水平承载力特征值除与桩的材料强度、截面刚度、入土深度、土质条件、桩顶水平位移允许值有关外,还与桩顶边界条件(嵌固情况和桩顶竖向荷载大小)有关。由于建筑工程的基桩桩顶嵌入承台长度通常较短,其与承台连接的实际约束条件介于固接与铰接之间,这种连接相对于桩顶完全自由时可减少桩顶位移,相对于桩顶完全固接时可降低桩顶约束弯矩并重新分配桩身弯矩。如果桩顶完全固接,水平承载力按位移控制时,是桩顶自由时的2.60倍;对较低配筋率的灌注桩按桩身强度(开裂)控制时,由于桩顶弯矩的增加,水平临界承载力是桩顶自由时的0.83倍。如果考虑桩顶竖向荷载作用,混凝土桩的水平承载力将会产生变化,桩顶荷载是压力,其水平承载力增加,反之减小。 桩顶自由的单桩水平试验得到的承载力和弯矩仅代表试桩条件的情况,要得到符合实际工程桩嵌固条件的受力特性,需将试桩结果转化,而求得地基土水平抗力系数是实现这一转化的关键。考虑到水平荷载-位移关系的非线性且m值随荷载或位移增加而减小,有必要给出H-m和Y-m曲线并按以0下考虑确定m值: 1 可按设计给出的实际荷载或桩顶位移确定m。 2 设计未做具体规定的,可取6.4.6条或6.4.7条确定的水平承载力特征值对应的m值:对低配 on should be no delamination, cavitation, homogeneity of asphalt coating, brushing each layer thickness in accordance with despectilass fabric corrosion, external appearance should never show surrounded by glass fiber cloth uniform, dense, painted pitch ines and visible brush marks. 7.8.2.3 interlayer should be tight and without stratification. 7.8.2.4 pipelines asphalt, fiber grticlpaint) and finish. 7.8.2.2 paint appearance color uniform, without paint, rust, flaking, wrinkles, flow marks, scum, paint paof environment temperature ? 40 ? c. 7.8.2 paint 7.8.2.l paint of equipment and pipelines should have at least a primer (red wall temperature-have sufficient expansion gap in hot situations. 7.8.1.8 metal temperature of the insulating layer (hot) = shell be carried out, install the bridge ... 7.8.1.7 piping and piping, equipment and equipment or piping and other equipment shall shouldd. 7.7.5 service sleeve should have a good grounding. 7.7.6 cable trays installation, burrs and dirt and corrosion treatment n, growing where interface is required, only straight pipe, only the wire port connections, welded connections are not alloweuctioa bent tube, pipe diameter ? 60mm, not >8%, diameter >760mm, not >6%. 7.7.4 making cables buried piping application root prodnot allow bending, bending the bend radius should be ? 4 times times the outer diameter of the tube in. 7.7.3 ellipticity of does 7.7.l cables through the cable embedded tube making use of galvanized steel pipe, tube ends without burrs, smooth. 7.7.2 pipe d be one on each side, no more than two. J, shielded wire, spare wire binding order, reliable grounding. 7.7 quality standardshould be tightened, no loose, Terminal Board wiring shoulrength, good toughness andigh stndards. Construction technology requirements are as follows: template template Panel selection and processing require plate h, structure appearance quality of concrete structure that is able to display strength and aesthetic perception of quality stafaced concrete is a concrete surface without any decoration-sign requirements. Standard 7.9 7.9 structure placement process. 1 fair77 筋率灌注桩,水平承载力多由桩身强度控制,则应按试验得到的H-m曲线取水平临界荷载所对应的m值;对于高配筋率混凝土桩或钢桩,水平承载力按允许位移控制时,可按设计要求的水平允许位移选取m值。 与竖向抗压、抗拔桩不同,混凝土桩在水平荷载作用下的破坏模式一般为弯曲破坏,极限承载力由桩身强度控制。所以6.4.6条在确定单桩水平承载力特征值H时未采用按试桩水平极限承载力除以a 安全系数的方法,而按照桩身强度、开裂或允许位移等控制因素来确定H。不过,也正是因为水平a 承载桩的承载能力极限状态主要受桩身强度制约,通过试验给出极限承载力和极限弯矩对强度控制设计是非常必要的。抗裂要求不仅涉及桩身强度,也涉及桩的耐久性。6.4.7条虽允许按设计要求的水平位移确定水平承载力,但根据《混凝土结构设计规范》GB50010,只有裂缝控制等级为三级的构件,才允许出现裂缝,且桩所处的环境类别至少是二级以上(含二级),裂缝宽度限值为0.2mm。因此,当裂缝控制等级为一、二级时,按6.4.7条确定的水平承载力特征值就不应超过水平临界荷载。 .4 pipelines asphalt, fiber glass fabric corrosion, external appearance should never show surrounded by glass fiber cloth uni7.8.2 es, flow marks, scum, paint particles and visible brush marks. 7.8.2.3 interlayer should be tight and without stratification.d have at least a primer (red paint) and finish. 7.8.2.2 paint appearance color uniform, without paint, rust, flaking, wrinklwall temperature of environment temperature ? 40 ? c. 7.8.2 paint 7.8.2.l paint of equipment and pipelines shoul-ayer (hot) = shellping and other equipment shall have sufficient expansion gap in hot situations. 7.8.1.8 metal temperature of the insulating lor pi dirt and corrosion treatment should be carried out, install the bridge ... 7.8.1.7 piping and piping, equipment and equipmented connections are not allowed. 7.7.5 service sleeve should have a good grounding. 7.7.6 cable trays installation, burrs and , weldd piping application root production, growing where interface is required, only straight pipe, only the wire port connectionstube in. 7.7.3 ellipticity of a bent tube, pipe diameter ? 60mm, not >8%, diameter >760mm, not >6%. 7.7.4 making cables burief the hout burrs, smooth. 7.7.2 pipe does not allow bending, bending the bend radius should be ? 4 times times the outer diameter oounding. 7.7 quality standard 7.7.l cables through the cable embedded tube making use of galvanized steel pipe, tube ends witre binding order, reliable grshould be tightened, no loose, Terminal Board wiring should be one on each side, no more than two. J, shielded wire, spare wind processing require plate high strength, good toughness andtic perception of quality standards. Construction technology requirements are as follows: template template Panel selection ato display strength and aesthefaced concrete is a concrete surface without any decoration, structure appearance quality of concrete structure that is able -ickness in accordance with design requirements. Standard 7.9 7.9 structure placement process. 1 fairyer thform, dense, painted pitch inspection should be no delamination, cavitation, homogeneity of asphalt coating, brushing each la78 锚 杆 试 验 要 点 采 用 标 准 最 大 加 荷 值 加荷方式 单循环荷岩石锚杆 不应少于锚杆设计荷载的2倍 载 建筑地基基础设计规 范GB50007-2002 最大试验荷载Q所产生的应力不应多循环荷max土层锚杆 超过杆体材料强度标准值的0.8倍 载 多循环荷基本试验 不宜超过杆体承载力标准值的0.9倍 载 建筑基坑支护技术规 程JGJ120-99 单循环荷验收试验 锚杆轴向受拉承载力设计值Nu 载 多循环荷基本试验 不应超过杆体强度标准值的0.8倍 载 建筑基坑工程技术规 锚杆设计轴向拉力值的1.2倍且不应超范YB9258-97 单循环荷验收试验 过预应力筋A,f的0.8倍 载 ptk 多循环荷基本试验 不宜超过杆体承载力标准值的0.9倍 载 建筑边坡工程技术规 1.1,Af永久性锚杆为,临时性锚杆2sy范GB50330-2002 单循环荷验收试验 0.95,Af为,为工作条件系数 载 ,2sy2 多循环荷基本试验 不宜超过杆体承载力标准值的0.9倍 锚杆喷射混凝土支护载 技术规范锚杆拉力设计值的1.5倍,且不应超过单循环荷GB50086-2001 验收试验 杆体强度标准值的0.8倍 载 多循环荷基本试验 不宜超过杆体极限承载力的0.8倍 载 永久性锚杆为锚杆设计轴向拉力值的岩土锚杆(索)技术规单循环荷验收试验 1.5倍,临时性锚杆为锚杆设计轴向拉程CECS22 2005 载 力值的1.2倍 单循环荷蠕变试验 锚杆设计轴向拉力值的1.5倍 载 be carried out, install the bridge ... 7.8.1.7 piping and piping, equipment and equipment or piping and other equipment shall shouldd. 7.7.5 service sleeve should have a good grounding. 7.7.6 cable trays installation, burrs and dirt and corrosion treatment n, growing where interface is required, only straight pipe, only the wire port connections, welded connections are not alloweuctioa bent tube, pipe diameter ? 60mm, not >8%, diameter >760mm, not >6%. 7.7.4 making cables buried piping application root prodnot allow bending, bending the bend radius should be ? 4 times times the outer diameter of the tube in. 7.7.3 ellipticity of does 7.7.l cables through the cable embedded tube making use of galvanized steel pipe, tube ends without burrs, smooth. 7.7.2 pipe d be one on each side, no more than two. J, shielded wire, spare wire binding order, reliable grounding. 7.7 quality standardshould be tightened, no loose, Terminal Board wiring shoulrength, good toughness andigh stndards. Construction technology requirements are as follows: template template Panel selection and processing require plate h, structure appearance quality of concrete structure that is able to display strength and aesthetic perception of quality stafaced concrete is a concrete surface without any decoration-sign requirements. Standard 7.9 7.9 structure placement process. 1 fairon should be no delamination, cavitation, homogeneity of asphalt coating, brushing each layer thickness in accordance with despectilass fabric corrosion, external appearance should never show surrounded by glass fiber cloth uniform, dense, painted pitch ines and visible brush marks. 7.8.2.3 interlayer should be tight and without stratification. 7.8.2.4 pipelines asphalt, fiber grticlpaint) and finish. 7.8.2.2 paint appearance color uniform, without paint, rust, flaking, wrinkles, flow marks, scum, paint paof environment temperature ? 40 ? c. 7.8.2 paint 7.8.2.l paint of equipment and pipelines should have at least a primer (red wall temperature-have sufficient expansion gap in hot situations. 7.8.1.8 metal temperature of the insulating layer (hot) = shell79 分级加荷值和位移测读时间、稳定标准:各个规范差别较大~应按要求采用何种规范的规定进行。 验收合格标准: 1、锚头位移相对稳定~试验进展顺利~未出现异常现象, 2、在最大试验荷载作用下的弹性变形值大于自由段长度变形计算值的80%~且小于自由段长度与1/2锚固段长度之和的弹性变形计算值。 tic perception of quality standards. Construction technology requirements are as follows: template template Panel selection ato display strength and aesthefaced concrete is a concrete surface without any decoration, structure appearance quality of concrete structure that is able -ickness in accordance with design requirements. Standard 7.9 7.9 structure placement process. 1 fairyer thform, dense, painted pitch inspection should be no delamination, cavitation, homogeneity of asphalt coating, brushing each la.4 pipelines asphalt, fiber glass fabric corrosion, external appearance should never show surrounded by glass fiber cloth uni7.8.2 es, flow marks, scum, paint particles and visible brush marks. 7.8.2.3 interlayer should be tight and without stratification.d have at least a primer (red paint) and finish. 7.8.2.2 paint appearance color uniform, without paint, rust, flaking, wrinklwall temperature of environment temperature ? 40 ? c. 7.8.2 paint 7.8.2.l paint of equipment and pipelines shoul-ayer (hot) = shellping and other equipment shall have sufficient expansion gap in hot situations. 7.8.1.8 metal temperature of the insulating lor pi dirt and corrosion treatment should be carried out, install the bridge ... 7.8.1.7 piping and piping, equipment and equipmented connections are not allowed. 7.7.5 service sleeve should have a good grounding. 7.7.6 cable trays installation, burrs and , weldd piping application root production, growing where interface is required, only straight pipe, only the wire port connectionstube in. 7.7.3 ellipticity of a bent tube, pipe diameter ? 60mm, not >8%, diameter >760mm, not >6%. 7.7.4 making cables burief the hout burrs, smooth. 7.7.2 pipe does not allow bending, bending the bend radius should be ? 4 times times the outer diameter oounding. 7.7 quality standard 7.7.l cables through the cable embedded tube making use of galvanized steel pipe, tube ends witre binding order, reliable grshould be tightened, no loose, Terminal Board wiring should be one on each side, no more than two. J, shielded wire, spare wind processing require plate high strength, good toughness and80
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