台背回填标准化施工工艺工法

    台背回填标准化施工工艺工法     编制单位：湖北省交通投资有限公司高速公路建设总指挥部湖北交投麻城至武穴高速公路建设指挥部四川公路桥梁建设集团有限公司（麻武穴高速土建二标项目部）二〇一四年九月     目录 一、总则·································································································11.1编制目的及意义·······················································································11.2编制依据·································································································11.3一般规定·································································································1二、施工工艺流程·····················································································3三、施工准备···························································································43.1施工人员准备··························································································43.2施工技术准备··························································································43.3施工机械准备··························································································43.4填料准备·································································································43.5施工现场准备··························································································43.6建立填筑台账··························································································4四、操作要点···························································································54.1涵（台）隐蔽工程验收··············································································54.2首件工程·································································································54.3回填范围清理··························································································54.4地基处理·································································································64.5沉降缝处理·····························································································64.6台阶挖设·································································································64.7标线的标注·····························································································64.8填料装运·································································································64.9摊铺·······································································································74.10平整压实·······························································································74.11质量控制·······························································································94.12场地清理·······························································································94.13验收·····································································································9五、质量通病的预防及处理········································································105.1质量通病的产生······················································································105.2病害的预防····························································································105.3病害的处置····························································································105.3.1液压强夯法·························································································105.3.2堆载预压法·························································································12六、安全管理·························································································14  1   第一章总则1.1编制目的及意义由于桥（涵）台为刚性体，桥头路基为弹塑性体，在路基填土自然固结沉降及行车荷载的长期作用下，桥（涵）台与桥头路基形成高差导致桥头跳车，所以桥（涵）台背回填在路基施工中是一项大家公认的质量控制薄弱环节，若施工、管理程序不到位或处理措施不妥，回填部分发生较大沉降，就会造成严重的路基病害。为进一步有效控制桥（涵）台背回填施工质量，尽可能减少桥头跳车现象，确保营运阶段行车的舒适性和安全性，以麻城至武穴高速公路MWTJ-2标段桥（涵）台背回填为例，编制本施工工艺。由于编者水平有限，时间仓促，如有不足之处，敬请指正。1.2编制依据1.《公路桥涵施工技术规范》（JTG/TF50-2011）2.《公路工程质量检验评定标准》（JTGF80/1-2004）3.《公路路基施工技术规范》JTGF10-20064.高速公路两阶段施工图设计文件5.湖北省高速公路建设标准化指南6.湖北交投麻城至武穴高速公路标准化建设实施细则7.湖北交投及麻武高速公路指挥部相关文件1.3一般规定1.桥（涵）台背回填开始前，应编制《桥（涵）台背回填专项施工方案》，明确施工机械设备、材料、作业人员配置和施工工艺、质量及安全管控措施，经监理工程师审查通过后，方可签署开工报告进行桥（涵）台背回填施工。2.桥（涵）台背回填的顺序应满足设计图纸要求，保证构件不产生附加水平推力。一般应遵循以下要求：拱桥台背填土应在主拱圈安装和砌筑之前在两侧对称回填；梁式桥的轻型桥台填土，应在梁板安装以后在两侧对称进行回填（有支撑梁的轻型桥台，回填必须在支撑梁安装或浇筑完成之后方可进行）；柱（肋板）式桥台应先完成台背回填，再浇筑盖梁。并应以单根柱（肋板）为单元两侧  2   对称、平行回填，回填施工应严防产生 桥台位移和偏心受压。当填至盖梁下，小型机械不能作业时，可用M7.5砂浆浆砌片石，分层铺砌至盖梁底。 3. 对于整体式箱涵（通道）应在其上部结构完成、混凝土强度达到设计强度的85%后；两侧对称进行回填。 4.通道（盖板涵）盖板施工完成（如盖板采用现浇施工则盖板养生期结束或按设计完成防水处理）后；圆管涵管节防水处理完成后；倒虹吸闭水试验完成应组织构造物隐蔽工程验收后方可进行桥（涵）台背及涵洞洞身两侧的回填。5.桥（涵）台背填料选择应遵循因地制宜，就地取材的原则。宜采用砂砾土、中粗砂、碎石土、开山毛渣、碎石等透水性材料或石灰土。若采用石灰土，其石灰剂量应满足设计文件要求；若采用砂砾土或中粗砂，其级配组成应为天然级配；若采用碎石土，其碎石含量应不小于50%；若采用碎石，其压碎值不大于30%、最大粒径不大于10cm；若采用开山毛渣，其黏粒含量应不大于5%。备料后试验室对填料进行检测，合格后进行回填。                  台背回填料准备 6.桥（涵）台背两侧回填土的压实，压路机应与墙体保持一定的距离(通常为50～60cm)。在压路机碾压不到的盲区，应采用人工配合小型机械夯填密实。桥台后地基如为软土，应按设计要求对地基进行处理并对台后填土进行预压，预压应在搭板施工前完成。  3   第二章  施工工艺流程             4   第三章  施工准备 3.1施工人员准备成立桥（涵）台背回填专业作业队伍，明确相应责任人和职责范围，对工程质量层层严格把关，并对各管理专班所有人员的相关资料信息上报驻地办及总监办存档备案。3.2施工技术准备熟悉相关设计图纸及规范要求，制定台背回填技术方案，项目部（项目各分部 ）组织各作业班组施工人员进行全面的施工技术交底工作，明确职责，使所有作业人员都明确每道工序的操作要点和工艺流程。 3.3施工机械准备配备专用的成套回填设备，包括挖掘机、压路机、推土机