生态风景区桥梁工程钻孔灌注桩桩基技术交底

'技术交底单2013年12月22日工程名称雁鸣湖生态风景区桥梁工程分项工程桩基交底时间交底地点参与人员接收单位负责人质检负责人交底人一、施工要求：1、本标段桥梁基础均为钻孔灌注桩，共16+40=56棵，桩位处地质条件为：粘质粉土。根据现场地质情况，拟采用回旋钻机成孔。2、工艺流程场地平整→桩位放样→制备护壁泥浆→护筒埋设→钻机就位→复验桩位→钻孔→成孔至设计高程→提钻→清孔→桩底检查→钢筋笼隐检→吊放钢筋笼→下导管→水下灌注混凝土并回收护壁泥浆→拔除护筒3、施工方法（1）场地平整将桥区进行清理、整平，保证桩基施工机械进场。。（2）桩位放样用全站仪测放出桩基的中心线位置。用三角网复测无误后，然后平行于桥位中心线的前后方向和横向两侧设置十字控制桩，同时做好控制桩的保护工作，防止施工期间被扰动。（3）护筒埋设、钻机就位在每个桩位处定出十字控制桩后，进行护筒埋设工作，测量孔深的基准点使用水准仪将高程引到护筒上，并做红漆标记。护筒采用5mm厚钢板制作，护筒内径应大于钻头直径10cm，长度2～3m，护筒顶部略微高出地面，周围夯实，护筒中心与桩位中心的偏差不得大于10mm。钻机就位时底座必须保持平稳，不发生倾斜移位，钻头中心采用Φ1000mm桩定位器对准桩位，定位误差不大于10mm。垂直度采用钻机自身的垂直检测装置控制，并辅以人工量测倾斜度。孔斜采用孔规测定，桩垂直度≤0.2％桩长。钻进深度采用测绳测量。钻到设计深度后停止钻进，孔深不得小于设计深度。施工时作好钻孔记录，并及时通知监理人员进行桩孔检查。anddifficultiesof1,theconstructionprocesstoensurerailwayoperationsafetyiskey.2,highwatertableintheprojectareas,thesoilsofterandGroutingtobridgeisrequired,howtocontroltheGrouting,satisfactoryeffecttoensuresafetyoperationsaregood,isapriorityintheconstructionofthisproject.3,inthecourseofjackingbridge,preventingthesubgradecollapseisanotherfocusofthisproject.4,whenjackingbridge,rectifyingandelevationcontrolisdifficult.3.constructionorganizationplan3.1.constructionorganizationscheme3.1.1.constructionorganizationandresponsibilitiesoftheDepartmentinordertoensurerailwaysafetyandthesafety,qualityofconstruction,ensurethattheownersofthequality,duration,target,Tianjin,aswellasrequirementsforconstructionandenvironmentalprotection,safe,civilized,thisengineeringprojectconstructionwillbeused.Iunitinjackingconstructionofframebridgehasextensiveexperienceinthemanagement,technicalstaffprojectmanagerasaconstructionorganization,withoverallresponsibilityforthemanagementandoperationofprojectsmanagement,completeandprofessionalandtechnicalpersonnelandskilledworkerstoundertaketheconstructiontasks.Alsocommittedtothekeymanagementpersonnelarenototherworkspart-time.Projectmanagementleadershipbytheprojectmanager,AssistantProjectManager,ChiefEngineer,ChiefSecurityOfficer,andconsistsof （4）制备泥浆护壁泥浆采用膨润土造浆，护壁泥浆经泥浆净化装置净化后重复利用。泥浆材料的选定及配合比：7～10％优质粘土；0.5～1％工业用碱；0.1％羟甲基纤维素(CMC)；另外根据施工情况掺入适量分散剂。要认真做好泥浆测试工作。新制备的泥浆、钻孔使用前、钻孔过程中、灌注砼前、回收泥浆后、泥浆处理后均要进行泥浆测试。钻孔施工中始终保持护筒内的泥浆面在护筒顶下0.5m左右。泥浆各项指标如下：（5）钻孔在一切准备就绪后，采用旋挖钻机钻孔，同时保证泥浆面始终不低于护筒顶0.4m。穿越流沙层时控制进尺，适当增大泥浆比重，并掺入黄粘土以防止扩孔、塌孔。（6）成孔质量检查a.孔深用测绳检验，深度不小于设计要求。b.垂直度用孔规吊入钻孔内检测，孔规外径比钢筋笼外径加100mm（不得大于钻头直径），长度为孔径的4~6倍，以孔规能顺利下至孔底为合格。（7）清孔钻孔达到图纸规定深度，且成孔质量符合要求后，应立即进行清孔。清孔时，孔内水位应保持在地下水位以上1.5～2m，以防止钻孔的任何塌陷。换浆法清孔后的泥浆指标应符合下列规定：相对密度1.05～1.2t/m3，粘度17～20s，含砂率＜4%，清孔后用孔底沉渣不得大于30mm，不得用加深孔底的方法来代替清孔。anddifficultiesof1,theconstructionprocesstoensurerailwayoperationsafetyiskey.2,highwatertableintheprojectareas,thesoilsofterandGroutingtobridgeisrequired,howtocontroltheGrouting,satisfactoryeffecttoensuresafetyoperationsaregood,isapriorityintheconstructionofthisproject.3,inthecourseofjackingbridge,preventingthesubgradecollapseisanotherfocusofthisproject.4,whenjackingbridge,rectifyingandelevationcontrolisdifficult.3.constructionorganizationplan3.1.constructionorganizationscheme3.1.1.constructionorganizationandresponsibilitiesoftheDepartmentinordertoensurerailwaysafetyandthesafety,qualityofconstruction,ensurethattheownersofthequality,duration,target,Tianjin,aswellasrequirementsforconstructionandenvironmentalprotection,safe,civilized,thisengineeringprojectconstructionwillbeused.Iunitinjackingconstructionofframebridgehasextensiveexperienceinthemanagement,technicalstaffprojectmanagerasaconstructionorganization,withoverallresponsibilityforthemanagementandoperationofprojectsmanagement,completeandprofessionalandtechnicalpersonnelandskilledworkerstoundertaketheconstructiontasks.Alsocommittedtothekeymanagementpersonnelarenototherworkspart-time.Projectmanagementleadershipbytheprojectmanager,AssistantProjectManager,ChiefEngineer,ChiefSecurityOfficer,andconsistsof 二、钻孔灌注桩质量通病防治：1.坍孔a.现象成孔过程中或成孔后，孔壁坍落，造成孔底积泥孔深不足。b、原因（1）上挖埋式护筒的底部和四周未用粘土填实，水中振动埋入护筒的深度不足或护筒底部埋设在砂类等透水层中。（2）孔内水位高度不够，不足以平衡水头压力。（3）水上钻孔时，孔内水位未随潮水涨落而作相应变动。（4）当钻至砂砾等强透水层时，水源补给不足引起孔内水位急剧下降。（5）出现教强承压水时，易导致孔底翻砂和孔壁坍塌。（6）钻孔附近的振动影响。（7）泥浆比重偏小。（8）成孔速度过快，在孔壁上来不急形成泥膜。（9）吊放钢筋笼时碰撞了孔壁或破坏了孔壁泥膜。（10）成孔后未及时浇筑混凝土。c、防治措施（1）陆上埋设护筒时，宜在护筒底部夯填50cm厚粘土，必须夯打密实。放置护筒后，在护筒四周对称均衡地夯填粘土，防止护筒变形移位，应夯填密实不渗水。（2）水中振动沉入护筒时，应根据地质资料，将护筒沉穿淤泥和透水层，护筒之间要有可靠的联系，使护筒不会因水流影响而晃动。（3）孔内水位必须稳定地高出孔外水位1m以上，在潮汐影响区域内钻孔时，宜有虹吸管等连通措施，以调节孔内水位。泥浆泵等钻孔配套设备能量应有一顶的安全系数，并应有备用设备，以应急需。（4）施工通道的布置应离孔位一定距离，尤其在地表下有淤泥质粘土之类的软弱土层时更应注意。（5）应根据不同土层采用不同泥浆比重。（6）应根据不同土层采取不同的转速，如在砂性土或含少量卵石中钻进时，可用一或二档转速，并控制进尺。在地下水位高的粉砂中钻进时，宜用低档慢速钻进，同时应加大泥浆比重和提高孔内水位。（7）钢筋笼的吊放、接长均应注意不碰撞孔壁。（8）尽量缩短成孔后至浇筑混凝土的时间间隔。（9）发生坍孔时，应用优质粘土回填至坍孔处1m以上，待自然沉实后再继续钻进。2.钻孔漏浆a、现象在成孔过程中或成孔后，孔内不能稳定持续一定水位，泥浆向孔外渗漏。b、分析原因（1）护筒埋置深度不够，泥浆从护筒底部流失。（2）护筒制作粗糙，接头和纵向拼缝处不严密，使泥浆产生渗漏。（3）护筒内静水压力过大，亦会发生护筒刃脚处泥浆渗漏。anddifficultiesof1,theconstructionprocesstoensurerailwayoperationsafetyiskey.2,highwatertableintheprojectareas,thesoilsofterandGroutingtobridgeisrequired,howtocontroltheGrouting,satisfactoryeffecttoensuresafetyoperationsaregood,isapriorityintheconstructionofthisproject.3,inthecourseofjackingbridge,preventingthesubgradecollapseisanotherfocusofthisproject.4,whenjackingbridge,rectifyingandelevationcontrolisdifficult.3.constructionorganizationplan3.1.constructionorganizationscheme3.1.1.constructionorganizationandresponsibilitiesoftheDepartmentinordertoensurerailwaysafetyandthesafety,qualityofconstruction,ensurethattheownersofthequality,duration,target,Tianjin,aswellasrequirementsforconstructionandenvironmentalprotection,safe,civilized,thisengineeringprojectconstructionwillbeused.Iunitinjackingconstructionofframebridgehasextensiveexperienceinthemanagement,technicalstaffprojectmanagerasaconstructionorganization,withoverallresponsibilityforthemanagementandoperationofprojectsmanagement,completeandprofessionalandtechnicalpersonnelandskilledworkerstoundertaketheconstructiontasks.Alsocommittedtothekeymanagementpersonnelarenototherworkspart-time.Projectmanagementleadershipbytheprojectmanager,AssistantProjectManager,ChiefEngineer,ChiefSecurityOfficer,andconsistsof c、防治措施（1）成孔过程中护筒内保持适当的静水压力（80—120）。（2）在安置护筒前严格验收护筒制作质量，并在纵、横接缝处设置止水垫片。（3）加稠泥浆，放慢钻进速度，钻至护筒刃脚处回填粘土，反复冲击，增强护壁效果。（4）护筒一般应埋置在粘土层内不少于1m处。3.成孔偏斜a.现象成孔后不垂直，偏差值大于规定的L/100。b、原因分析（1）施工现场不平整，不坚实，在支架上钻孔时，支架的承载力不够，发生不均匀沉降，导致钻杆不垂直。（2）钻机部件磨损，接头松动，钻杆弯曲。（3）钻头晃动偏离轴线，扩孔较大。（4）遇有地下障碍物把钻头挤偏。c、防治措施（1）钻机就位时，应使转盘，底座水平，使天轮的轮缘、钻杆的卡盘和护筒的中心在同一垂直线上，并在钻进过程中防止位移。（2）场地平整坚实，支架的承载力满足要求，在发生不均匀沉降时必须随时调整。（3）偏斜过大时应回填粘土，待沉积密实后在钻。4.缩孔a、现象成孔过程中或成孔后局部孔径小于设计要求。b、原因分析（1）软土层受地下水位影响和周边车辆振动。（2）塑性土膨胀，造成缩孔。c、预防措施采用钻头上下反复扫孔，将孔径扩大至设计要求。5.孔深不足a、现象在浇筑混凝土前复量孔深发现不足。b、分析原因（1）孔壁坍塌，土方淤积于孔底。（2）清孔不足，孔底回淤。c.、防治措施（1）吊放钢筋笼时不得碰撞孔壁。（2）必须二次清孔，清孔后的泥浆密度应小于1.１５。（3）尽量缩短成孔至浇筑混凝土的时间间隔。anddifficultiesof1,theconstructionprocesstoensurerailwayoperationsafetyiskey.2,highwatertableintheprojectareas,thesoilsofterandGroutingtobridgeisrequired,howtocontroltheGrouting,satisfactoryeffecttoensuresafetyoperationsaregood,isapriorityintheconstructionofthisproject.3,inthecourseofjackingbridge,preventingthesubgradecollapseisanotherfocusofthisproject.4,whenjackingbridge,rectifyingandelevationcontrolisdifficult.3.constructionorganizationplan3.1.constructionorganizationscheme3.1.1.constructionorganizationandresponsibilitiesoftheDepartmentinordertoensurerailwaysafetyandthesafety,qualityofconstruction,ensurethattheownersofthequality,duration,target,Tianjin,aswellasrequirementsforconstructionandenvironmentalprotection,safe,civilized,thisengineeringprojectconstructionwillbeused.Iunitinjackingconstructionofframebridgehasextensiveexperienceinthemanagement,technicalstaffprojectmanagerasaconstructionorganization,withoverallresponsibilityforthemanagementandoperationofprojectsmanagement,completeandprofessionalandtechnicalpersonnelandskilledworkerstoundertaketheconstructiontasks.Alsocommittedtothekeymanagementpersonnelarenototherworkspart-time.Projectmanagementleadershipbytheprojectmanager,AssistantProjectManager,ChiefEngineer,ChiefSecurityOfficer,andconsistsof 6.钢筋笼变形a、现象钢筋笼在堆放、运输和吊装过程中，产生不可复原的变形。b、原因分析　（１）钢筋笼分段太长，加强箍设置不足，刚度不够。　（２）钢筋笼在堆放、运输和吊装过程中未严格按照技术规程，产生累积变形。c防治措施　（１）钢筋笼过长时应分节制作，分节吊装，然后在孔口焊接。　（２）应根据技术规程要求设置加强箍，加强箍必须与主筋焊接牢固。　（３）在安装钢筋笼时，宜设置临时吊装扁担，以增加刚度。7.钢筋笼位置偏差a、现象钢筋笼平面位置的偏差超过了质量标准的允许范围。b、分析原因　（１）钢筋笼上未设置垫块或垫块不足，不能有效控制混凝土保护层厚度。　（２）桩孔本身有较大偏差。　（３）钢筋笼未垂直吊放入孔，而是斜插入孔内。c、防治措施　（１）在钢筋笼主筋上，应每隔一段距离设置一组垫块，以此控制混凝土的保护层厚度，并使钢筋笼的平面位置对准桩孔轴线。　（２）偏差的桩孔应吊放钢筋笼前反复扫孔纠正。　（３）钢筋笼应在垂直状态时吊放入孔。8.钢筋笼上浮a、现象浇筑混凝土时钢筋笼上浮。b、分析原因　（１）混凝土在进入钢筋笼底部时浇筑速度过快。　（２）钢筋笼未采取固定措施c、防治措施　（１）当混凝土上升到接近钢筋笼下端时，应放慢浇筑速度，减少混凝土面上升的动能作用，以免钢筋笼被顶托而上浮。当钢筋笼被埋入混凝土中一定深度时，在提升导管，减少导管埋入深度，使导管下端高出钢筋笼下端有相当距离时再按正常速度浇筑，在通常情况下，可防止钢筋笼上浮。　（２）浇筑混凝土前，应将钢筋笼固定在孔位护筒上，可防止上浮。8.断桩anddifficultiesof1,theconstructionprocesstoensurerailwayoperationsafetyiskey.2,highwatertableintheprojectareas,thesoilsofterandGroutingtobridgeisrequired,howtocontroltheGrouting,satisfactoryeffecttoensuresafetyoperationsaregood,isapriorityintheconstructionofthisproject.3,inthecourseofjackingbridge,preventingthesubgradecollapseisanotherfocusofthisproject.4,whenjackingbridge,rectifyingandelevationcontrolisdifficult.3.constructionorganizationplan3.1.constructionorganizationscheme3.1.1.constructionorganizationandresponsibilitiesoftheDepartmentinordertoensurerailwaysafetyandthesafety,qualityofconstruction,ensurethattheownersofthequality,duration,target,Tianjin,aswellasrequirementsforconstructionandenvironmentalprotection,safe,civilized,thisengineeringprojectconstructionwillbeused.Iunitinjackingconstructionofframebridgehasextensiveexperienceinthemanagement,technicalstaffprojectmanagerasaconstructionorganization,withoverallresponsibilityforthemanagementandoperationofprojectsmanagement,completeandprofessionalandtechnicalpersonnelandskilledworkerstoundertaketheconstructiontasks.Alsocommittedtothekeymanagementpersonnelarenototherworkspart-time.Projectmanagementleadershipbytheprojectmanager,AssistantProjectManager,ChiefEngineer,ChiefSecurityOfficer,andconsistsof a、现象成桩后经探测，桩身局部没有混凝土，存在泥夹层，造成断桩。b、分析原因　（１）混凝土塌落度太小，骨料太大，运输距离过长，混凝土和易性差，致使导管堵塞，疏通堵管再浇混凝土时中间会形成夹泥层。　（２）计算导管埋置深度时出错，或盲目提升导管，使导管脱离混凝土面，再浇筑混凝土时中间就会出现夹泥层。　（３）钢筋笼将导管卡住，强力拔管时，使泥浆混入混凝土中。　（４）导管接头处渗漏，泥浆进入管内，混入混凝土中。　（５）混凝土供应中断，不能连续浇筑，中断时间过长，造成堵管事故。c、预防措施　（１）混凝土配合比应严格按照有关水下混凝土的规范配制，并经常测试塌落度，防止导管堵塞。　（２）严禁不经测算盲目提升导管，防止导管脱离混凝土面。　（３）钢筋笼主筋接头要焊平，以免提升导管时，法兰挂住钢筋笼。　（４）浇筑混凝土应使用经过检漏和耐压试验的导管。　（５）浇筑混凝土前应保证混凝土搅拌机能正常运转，必要时应有一台备用搅拌机做应急之用。治理方法　（１）当导管堵塞而混凝土尚未初凝时，可吊起导管，再吊起一节钢轨或其他重物在导管内冲击，把堵管的混凝土冲散或迅速提出导管，用高压水冲掉堵管混凝土后，重新放入导管浇筑混凝土。　（２）当断桩位置在地下水位以上时，可抽掉桩孔内泥浆，在钢筋笼的保护下，人下到桩孔中，对先前浇筑的混凝土面进行凿毛，处理并清洗钢筋，然后继续浇筑混凝土。　（３）当断桩位置在地下水位以下时，可用直径较原桩直径较小的钻头，在原桩位处钻孔，钻至断桩部位以下适当深度时，重新清孔，并在断桩部位增加一节钢筋笼，笼的下半截埋入新钻的孔中，然后继续浇筑混凝土。　（４）当导管被钢筋笼挂住时，如果钢筋笼埋入混凝土中不深，可提起钢筋笼，转动导管，使导管脱离，如果钢筋笼埋入混凝土中很深，只好放弃导管。　（５）灌注桩因为严重塌方而断桩或导管拔出后重新放入导管时均形成断桩，是否需要在原桩外侧补桩，需检测后与有关单位伤定。anddifficultiesof1,theconstructionprocesstoensurerailwayoperationsafetyiskey.2,highwatertableintheprojectareas,thesoilsofterandGroutingtobridgeisrequired,howtocontroltheGrouting,satisfactoryeffecttoensuresafetyoperationsaregood,isapriorityintheconstructionofthisproject.3,inthecourseofjackingbridge,preventingthesubgradecollapseisanotherfocusofthisproject.4,whenjackingbridge,rectifyingandelevationcontrolisdifficult.3.constructionorganizationplan3.1.constructionorganizationscheme3.1.1.constructionorganizationandresponsibilitiesoftheDepartmentinordertoensurerailwaysafetyandthesafety,qualityofconstruction,ensurethattheownersofthequality,duration,target,Tianjin,aswellasrequirementsforconstructionandenvironmentalprotection,safe,civilized,thisengineeringprojectconstructionwillbeused.Iunitinjackingconstructionofframebridgehasextensiveexperienceinthemanagement,technicalstaffprojectmanagerasaconstructionorganization,withoverallresponsibilityforthemanagementandoperationofprojectsmanagement,completeandprofessionalandtechnicalpersonnelandskilledworkerstoundertaketheconstructiontasks.Alsocommittedtothekeymanagementpersonnelarenototherworkspart-time.Projectmanagementleadershipbytheprojectmanager,AssistantProjectManager,ChiefEngineer,ChiefSecurityOfficer,andconsistsof 四、施工安全措施1、严格按照施工规范和安全操作规程施工，在作业地点挂警示牌，严禁违章操作，野蛮施工。2、经理部内有严密的安全监督体系，并经常对参施人员进安全教育，提高安全意识。3、专职安全员要认真做好安全监督工作，建立安全台帐，对进入施工现场的机械及参施人员进行安全教育。4、凡进入施工场地，须戴好安全帽，不得酗酒。5、机械作业随时检查用电等的安全隐患，不得违章操作。6、吊车作业时，其臂下严禁站人，信号工不得违规操作、指挥。7、施工人员在防撞墩安装时，必须配带安全帽，系好安全带五、环保、消防措施1、施工现场应经常保持整洁卫生，运输车辆不带泥砂，并做到沿途不遗撒。2、办公室、职工宿舍应保持整洁有序，生活区周围应保持卫生，无污染物，污水、生活垃圾集中堆放及时清理。3、伙房内要整洁，炊具用具必须干净，无腐烂变质食品。4、施工现场应供应开水，饮水器具要卫生。5、消防保卫人员应昼夜值班，并记录值班日志。6、临建符合防火规定，并设有消火栓，保证道路的畅通无阻。7、生活区内不许使用电炉和私设炉灶，电源线不得随意拉接。8、、施工材料的存放及保管应符合防火安全要求，库房应用非燃料支搭，易燃易爆物品应专库储存，分类单独存放，保持通风。9、严格用火制度，施工现场电气焊明火地点必须设水桶，灭火器等。记录：复核：日期：anddifficultiesof1,theconstructionprocesstoensurerailwayoperationsafetyiskey.2,highwatertableintheprojectareas,thesoilsofterandGroutingtobridgeisrequired,howtocontroltheGrouting,satisfactoryeffecttoensuresafetyoperationsaregood,isapriorityintheconstructionofthisproject.3,inthecourseofjackingbridge,preventingthesubgradecollapseisanotherfocusofthisproject.4,whenjackingbridge,rectifyingandelevationcontrolisdifficult.3.constructionorganizationplan3.1.constructionorganizationscheme3.1.1.constructionorganizationandresponsibilitiesoftheDepartmentinordertoensurerailwaysafetyandthesafety,qualityofconstruction,ensurethattheownersofthequality,duration,target,Tianjin,aswellasrequirementsforconstructionandenvironmentalprotection,safe,civilized,thisengineeringprojectconstructionwillbeused.Iunitinjackingconstructionofframebridgehasextensiveexperienceinthemanagement,technicalstaffprojectmanagerasaconstructionorganization,withoverallresponsibilityforthemanagementandoperationofprojectsmanagement,completeandprofessionalandtechnicalpersonnelandskilledworkerstoundertaketheconstructiontasks.Alsocommittedtothekeymanagementpersonnelarenototherworkspart-time.Projectmanagementleadershipbytheprojectmanager,AssistantProjectManager,ChiefEngineer,ChiefSecurityOfficer,andconsistsof'