土方开挖与回填土施工方案

1目录一、编制依据··················································································2二、工程概况··················································································2三、土方开挖方案············································································3（一）、开挖准备··············································································31、基坑周边及基坑内排水措施·······················································32、基坑测量定位·········································································33、施工人员及材料设备的准备·······················································34、施工用电及施工照明的准备·······················································4（二）、基坑开挖的原则、顺序和方法···················································4（三）、主要机械设备计划··································································4（四）、主要施工方法与要求·······························································51、技术措施···············································································52、基槽验收···············································································6四、土方回填方案············································································61、土料要求与含水量控制····························································62、基底处理···············································································73、压实的一般要求·····································································74、质量控制与检验······································································8五、工期与工期保障措施···································································8六、土方坍塌应急预案·····································································101、现场可能发生坍塌事故的环节····················································102、预防措施··············································································103、应急预案工作流程图·······························································104、基坑安全处理措施··································································11七、安全管理·················································································11八、文明施工·················································································122土方开挖与回填土施工方案一、编制依据1、××××××××工程《施工组织设计》；2、××××××××工程施工总平面布置图；3、××××××××工程设计文件；4、××××××××工程《地质勘察报告书》；5、《建筑工程质量验文件收统一标准》（GB50300-2001）；6、《建筑地基基础施工质量验收规范》（GB50202-2002）；7、《建筑施工安全检查标准》（JGJ59-1999）；8、《施工现场临时用电安全技术规范》（JGJ46-2005）；9、《建筑机械使用安全技术规范》（JGJ33-2002）；二、工程概况××工程位于××省××市××区××镇，工程由××设计研究院有限公司设计，××市地质勘探院地质勘察，××省建设监理有限公司监理，××公司总承包。本工程±0.000ｍ，相当于黄海高程20.5ｍ。工程总建筑面积11700㎡，建筑基底面积7900㎡，钢筋砼独立基础，柱网为9*9m，建筑总高度为21.15ｍ。基础开挖基底相对标高分别为-2.6m；-3.1m；-4.6m；-5.1m等，实际开挖深度分别为2.3m；2.8m；4.3m；4.8m等。根据地质勘察报告及施工场地比较开阔，无障碍物，便于施工布置的特点。基础采用机械大开挖分层作业施工的方法人工清底的预留厚度为300㎜，土方开挖量22000m3，开挖出的土方在施工区附近集中堆放，基础回填结束后剩下的土方，全部外运出机场区域。3三、土方开挖方案（一）、开挖准备本工程地基与基础施工阶段，在当地正处于雨期季节，做好土方开挖前期各项准备工作至关重要，也十分必要。1、基坑周边及基坑内排水措施为防止基坑上部的地表、地面的水流入基坑内，基坑周边要做好组织排水。（1）、离基坑上口50-80cm处设40cm高、60cm宽排水沟（必要时用砌筑），与硬化地面连接，形成封闭状态。（2）、为确保雨期基槽不被雨水浸泡，需在基槽内每18M(离开承台位置)设600*600大小、挖深800mm的集水井（具体数量和布局可视天气情况而定），将基槽内雨水利用明排方法排至集水井内，并用污水泵及时强排至场外。（3）、雨施期间，安排专人观测水位情况，特别是在中、大雨过后，如发现水位异常上升时需采取措施加强降水。2、基坑测量定位根据施工图纸及轴线控制点进行测量放线，挖土时不允许超线开挖。基坑开挖前先进行测量定位，抄平放线，确定基坑平面尺寸和每个承台的外围线。根据本工程的±0.000标高原点，边挖土边测标高，直至挖到设计要求高度。3、施工人员及材料设备的准备施工现场管理人员及各岗位操作人员均应到位，对作业人员进行详细的书面技术交底，项目管理技术人员、现场各专业负责人必须吃透施工图纸领会施工方案的各项要求和工艺技术标准，并向所有施工人员进行交底。基坑开挖时所有材料及应急材料按计划全部到位。44、施工用电及施工照明的准备利用晴好天气采取连续施工作业方法，夜间挖土工作时间长，为保证充分的施工照明，拟在场地内搭设六只高度为4m～6m的照明灯架，每个灯架安装功率2000kw镝灯，工作面处配置15只活动碘钨灯。（二）、基坑开挖的原则、顺序和方法1、开挖原则。根据本工程柱网密、基础深、基底标高不一致的特点，基坑开挖必须坚持遵守“分段施工、分层开挖、先中间后周围、成半岛形开挖”的原则。2、开挖顺序。基坑开挖顺序由西向东，从拟建工程的○10-○11轴间（后浇带）分开，第一施工段为○1-○10轴；第二施工段为○11-○17轴。用三台挖掘机同时开挖（一台配合施工）；一台在中间○B-○C轴先行作业，要有一定的安全作业空间后，南、北两台即可开挖作业，形成既分散开挖、又整体推进施工作业流程。3、开挖方法。基坑土方开挖采用分层、分块、对称、限时和严禁超挖的方法进行。○A轴分别按2.8m、4.3m、4.8m、5.3m的深度分层进行开挖。其他基坑均按2.3m的深度一次性开挖到位的方法进行。中间○B-○C轴挖出的土用自卸运输车运出场地，南、北两边的土就随即甩至坑外装载机、挖掘机配合疏散。（三）、主要机械设备计划5本工程计划投入如下机械、设备（材料）序号名称规格单位数量1全站仪NTS302台12经纬仪J6台13水准仪S3台24塔尺5m根25反铲挖掘机1m3辆46推土机DC140辆17装载机ZT50辆28自卸运输车康明斯25T辆69压路机15T带震动辆110抽水泵扬程50m台1011防水彩条布㎡400012钢管φ48m150013手推车辆1014铁锹把4015蛙式打夯机台416平板振动夯ZH85台2（四）、主要施工方法与要求根据本工程特点，基坑采用机械大开挖，按两个施工段、分层施工的方法整体推进。必须严格按照其放坡的灰线进行开挖，。由3台反铲挖掘机从西①轴向东○17轴开挖，6辆运输车运土，1台挖掘机和1台推土机负责转运堆土和修坡，1台装载机和1台压路机配合修路。1、技术措施（1）、施工前由现场负责人向所有参加施工的人员进行有针对性的技术6交底，必须使每个操作者对施工中的技术要求心中有数。管理人员要了解施工机械设备的技术参数与性能，做好维修保养，科学合理地安排施工，尽量做到24小时人歇机械不歇。（2）、基底标高的控制。当土方开挖快接近基底标高时，在边坡上用钢筋并撒上白灰作出基底标高控制线，使槽底预留达到20cm土方，其中10cm土方用人工进行开挖，最后保留的10cm土层，待钎探进行后再用人工清槽。（3）充分发挥集水坑的效能。严格按设计方案布控集水坑，切实做好防水布（薄膜）的遮盖工作，严防基坑浸泡或爆晒。现场排水时采用电动潜水泵及时将集水坑的水排除场外。整个地基与基础施工过程派专人进行值班，确保施工正常进行。2、基槽验收人工清理基槽到设计标高时，及时通知设计单位、地质勘察单位、建设单位、监理单位进行基槽验收。验收内容：地质情况，基槽验线、尺寸、标高、基底地质情况。同时签署有关资料文件，合格后，才能进行下一道工序施工。四、土方回填方案本工程基础下采用褥垫渣褥垫。基础持力层为3层粉质粘土夹砾石和4层砂砾岩为基础持力层，如遇岩石地段开挖高度为基础埋深加300，采用褥垫渣褥垫。处理回填措施，褥垫层每次虚铺厚度可取300mm。褥垫材料采用炉渣施工时，严格控制夯填度，炉渣取0．65。1、土料要求与含水量控制填方土料应符合设计要求，应选择含水量符合压实要求的土作为填料，保证填方的强度和稳定性。填土土料含水量的大小，直接影响到夯实（碾压）质量，在夯实（碾压）前应先试验，以得到符合密实度要求条件下的最优含水量和最少夯实（或碾压）遍数。含水量过小，夯压（碾压）不实；7含水量过大，则易成橡皮土。粘性土料施工含水量与最优含水量之差可控制在-4%～＋2%范围内（使用振动碾时，可控制在-6%～＋2％范围内）。土料含水量一般以手握成团，落地开花为适宜。当含水量过大，应采取翻松、晾干、风干、换土回填、掺入干土或其他吸水性材料等措施；如土料过干，则应预先洒水润湿。2、基底处理（1）、场地回填应先清除基底上垃圾、草皮、树根，排除坑穴中积水、淤泥和杂物，并应采取措施防止地表滞水流入填方区