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马山旧城改造一期项目A地块人工挖孔灌注墩施工方案目录一、工程概况·························································································1二、施工准备·························································································32.1材料及主要机具：········································································32.2作业条件：··················································································4三、操作工艺·························································································4四、质量标准·························································································94.1保证项目：················································································104.2基本项目：················································································104.3允许偏差项目·············································································10五、成品保护························································································11六、应注意的质量问题············································································11九、主要安全技术措施············································································18十、质量记录························································································20十一、墩孔塌孔应急预案·········································································2011.1目的························································································2011.2适用范围·················································································2011.3相关文件·················································································2011.4工程概况、危险目标的确定及潜在危险性的评估······························2111.5应急救援指挥领导小组机构、职责················································2111.6救援专业队伍的分工··································································2211.7对内外的交流···········································································2211.8应急设备·················································································2311.9伤害人员的抢救措施··································································2311.10有关规定················································································24实用标准文案精彩文档第一章工程概况1.1工程概况本工程为马山工业园旧城改造一期项目A地块，本工程位于武汉市江夏区谭鑫培路与马山路交汇处。本子项位于A地块，A地块包含A1#、A2两栋3层的商业裙房，A3#为29层的住宅，A4#为31层的住宅。各主楼尺寸如下：1、地下室平面尺寸为189.7m*139.9m，地下室层数为两层，负二层结构层高3.85m，负一层结构层高5.7m。2、A1#平面尺寸为80.25m*107.5m，一层层高5.7m，二层层高5.5m，三层层高11.05m，建筑总高度22.3m。3、A2#平面尺寸为100.55m*107.5m，一层层高5.7m，二层层高5.5m，实用标准文案精彩文档三层层高5.15m，建筑总高度16.4m。4、A3#平面尺寸为58.22m*14.60m，裙房部分层高同A1#，标准层层高为2.95m，建筑总高度99.8m，属A类高度高层建筑。5、A4#平面尺寸为58.22m*14.60m，裙房部分层高同A2#，标准层层高为2.95m，建筑总高度99.85m，属A类高度高层建筑。人工挖孔墩位于A4#楼B2~B5/CA~AA区域。根据本工程基础勘察报告并结合现场实际试挖情况，基础持力层（强风化粉砂泥质岩）深度在2.5~5m左右，根据设计要求采用墩径φ1000圆形（扩底墩）人工挖孔墩加钢筋混凝土支护体系。进入持力层≥500mm，墩身采用C35级混凝土。基础等级：甲级1.2地质概况1.2.1根据武汉地质工程勘察院提供的马山工业园旧城改造一期（A地块）项目岩土工程勘察报告，本工程场地内地层按其成因、结构特征及强度自上而下共分为6层，上层滞水水位0.5m~2.6m（18.23~21.69m）各岩土层的地质时代及成因类型、顶板埋深、顶板标高、厚度、空间分布、岩土特征、工程性质详见下表：地层编号地层名称地层成因顶板埋深地层厚度层顶标高颜色状态压缩性包含无及特征分布情况①杂填土Qml0.000.50~6.6019.21~23.81杂色松散高主要由粘性土组成，土层结构松散、性质不均匀，为新近回填土。局部缺失②-1粉质粘土Q4al0.50~6.600.70~5.4014.37~20.11黄褐灰褐可塑中土质较均，含少量黑色铁锰质氧化物，干强度中等。局部缺失②-2淤泥质粘土Q4al1.20~1.60~14.04~灰褐色软塑高土质较均，含少量黑色腐殖质壳，手搓可成条。局部实用标准文案精彩文档8.504.3019.68分布②-3含角砾粉质粘土Q3el+dl0.00~10.500.70~6.0011.74~20.52黄褐色硬塑中土质不均，局部偏可塑，含20%~35%泥岩或石英砂岩角砾，局部富集。局部分布③-1强风化粉砂质泥岩S2f0.00~13.50最大揭露厚度50.5m7.78~24.01青灰色强风化低粉砂-泥状结构，中厚层状构造，泥质胶结。岩体基本质量等级为V级。全场分布③-2中风化粉砂质泥岩S2f2.50~45.50未揭穿-22.8~22.58青灰色中风化不可压缩粉砂-泥状结构，中厚层状构造，泥质胶结。岩体基本质量等级为Ⅳ级。全场分布场地土类型和场地类别场地土层主要为杂填土、粉质粘土、淤泥粘土、含角砾粘土。根据勘察经验场地土质fak大于150kPa。第二章施工准备2.1材料及主要机具2.1.1水泥：宜采用325号矿渣硅酸盐水泥。2.1.2砂：中砂或粗砂，含泥量不大于5%。石子：粒径为0.5～3.2cm的卵石或碎石。墩身混凝土采用商品混凝土。水：用自来水2.1.6钢筋：钢筋的级别、直径必须符合设计要求，有出厂证明书及复试报告。2.1.7一般应备有绞架、手推车或翻斗车、镐、锹、手铲、钎、线坠、定滑轮组、导向滑轮组、吊桶、振捣棒、插钎、粗麻绳、钢丝绳、安全活动盖板、防水照明灯（低压36V、100W），电焊机、扬程水泵、安全帽、安全带等。实用标准文案精彩文档2.1.8模板：组合式木模，弧形工具式木模二块拼装。卡具、挂钩和零配件。木板、木方等。2.2作业条件：2.2.1开挖前场地应完成三通一平。地上、地下的电缆、管线、旧建筑物、设备基础等障碍物均已排除处理完毕。各项临时设施，如照明、动力、通风、安全设施准备就绪。2.2.2熟悉施工图纸及场地的地下土质、水文地质资料，做到心中有数。2.2.3按配套道路，挡墙施工总平面图，设置墩位轴线、定位点；墩孔四周撒灰线。测定高程水准点。放线工序完成后，办理预检手续。2.2.4按设计要求分段制作好钢筋笼。2.2.5在地下水位比较高的区域，先降低地下水位至墩底以下0.5m左右。2.2.6人工挖孔操作的安全至关重要，开挖前应对施工人员进行全面的安全技术交底；操作前对吊具进行安全可靠的检查和试验，确保施工安全。第三章操作工艺3.1工艺流程：人工挖孔墩施工流程如图01所示。场地平整测量放线、定墩位开挖墩孔土方局部护壁拆除首节开挖施工锁口和护壁实用标准文案精彩文档3.1.2放线定墩位及高程：在场地三通一平的基础上，依据建筑物测量控制网的资料和基础平面布置图，测定墩位轴线方格控制网和高程基准许点。确定好墩位中心，以中点为圆心，以墩身半径加护壁厚度为半径画出上部（即第一步）的圆周。撒石灰线作为墩孔开挖尺寸线。孔位线定好之后，必须经有关部门进行复查，办好预检手续后开挖。3.1.3开挖第一节墩孔土方：开挖墩孔应从上到下逐层进行，先挖中间部分的土方，然后扩及周边，有效地控制开挖孔的截面尺寸。每节的高度应根据土质好坏、操作条件而定，一般以0.5～1m为宜。3.1.4支护壁模板附加钢筋：为防止墩孔壁坍方，确保安全施工，成孔设置井圈，其种类有素混凝土和钢筋混凝土两种。以现浇钢筋混凝土井圈为好，与土壁能紧密结合，稳定性和整体性能均佳，且受力均匀，实用标准文案精彩文档可以优先选用。当墩孔直径不大，深度较浅而土质又好，地下水位较低的情况下，也可以采用喷射混凝土护壁。护壁的厚度应根据井圈材料、性能、刚度、稳定性、操作方便、构造简单等要求，并按受力状况，以最下面一节所承受的土侧压力和地下水侧压力，通过计算来确定。护壁模板采用拆上节、支下节重复周转使用。模板之间用卡具、扣件连接固定，也可以在每节模板的上下端各设一道圆弧形的、用槽钢或角钢做成的内钢圈作为内侧支撑，防止内模因受力而变形。不设水平支撑，以方便操作。第一节护壁以高出地坪150～200mm为宜，便于挡土、挡水。墩位轴线和高程均应标定在第一节护壁上口，护壁厚度按设计要求。3.1.5浇筑第一节护壁混凝土：墩孔护壁混凝土每挖完一节以后应立即浇筑混凝土。人工浇筑，人工捣实，混凝土强度为C35，坍落度控制在100~120mm，确保孔壁的稳定性。3.1.6检查墩位（中心）轴线及标高：每节墩孔护壁做好以后，必须将墩位十字轴线和标高测设在护壁的上口，然后用十字线对中，吊线坠向井底投设，以半径尺杆检查孔壁的垂直平整度。随之进行修整，井深必须以基准点为依据，逐根进行引测。保证墩孔