文档介绍：轻型井点降水施工方案XX工程公司X年x月x日目录一、工程概况···································································2二、编制依据····································································2三、降水方案选择·······························································2四、井点降水相关计算·························································3五、主要降水设备·······························································6六、施工工期·····································································7七、井点施工方法·······························································7八、质量标准及质量保证措施················································8九、危险点分析································································10十、安全生产及文明施工措施···············································10十一、环保措施································································11工程概况本期设计为2×600MW亚临界汽轮发电机组。工程地质情况:本工程持力层采用③圆砾层做持力层,③圆砾,~,~。④细中砂层,~。~。⑤圆砾层分布于④层之下。~。⑥粘土(残积土),褐色,稍湿,坚硬,覆于凝灰岩之上。。编制依据《火电施工质量检验及评定标准》《电力建设施工及验收技术规范》《建筑施工计算手册》临时土方开挖图纸降水方案选择该项目地处伊敏河畔,属砂砾地质结构,渗透系数为150m/天,容水量大,受降水影响地下水位波动变幅1-2m。枯水期在-6m左右。而本工程大部分建筑物埋深在-6m,处于临界状态,丰水期就无法施工,本工程采取的措施是:采用明沟、集水井的方式进行作业层表面水的降水。在枯水期柱、基础底脚施工完、回填完,防止丰水期淹没,以减少降水施工的降水费用。基础埋深超过-6m的,采用局部井点降水。本工程主厂房基础底标高为-,不须采用井点降水,而循环水泵坑及汽轮机基础底标高为-,可采用轻型井点降水。基础平面基底长度约为50m,宽度约为36m。基础埋深为见施工图,地面持力层为圆砾层,井点降水可以避免大量涌水、冒泥、翻浆,而且在砂砾地层中开挖基坑时,可防止流砂现象发生,渗流向下改善土的性质,使基底土质更加密实,结合本工程基础施工主要在枯水期期间,周期较长的特点,采用轻型井点降水法,沿建筑物环状布置进行人工降水。同时基坑二角设集水箱配合4台QY-。井点降水相关计算1、井点管的埋设深度H≥H1+h+iL+l式中H——井点管的埋设深度(m)H1——井点埋设面至基坑底面距离(m)——基坑中央最深挖掘面至降水曲线点的安全距离(m)——井点管中心至基坑中心的短边距离(m)取27i——降水曲线坡度取1/10l——滤管长度(m)≥++27×1/10+=、涌水量计算(2H-S)SLgR-LgXOQ=——井点系统总涌水量(m3/d)K——渗透系数(m/d)取150H——含水层厚度(m)计算暂取11mR——抽水影响半径(m)计算取91S——水位降低值(m),——基坑设想半径(m)计算取24本工程以无压非完整井计算(2×11-)×-Lg24Q=×150=8818m3/d3、计算井点管数量和间距单井出水量q=65πdl×3K=65××××3150=65m3/d需井点管数量:n==149根基坑四角处及机械入口处井点管应加密,则采用的井点管数量为149+32=181根井点管间距平均为D=2×86/(181-1