1 目 录 1 ．沉井工程概况 ................................................................................................................ 1 1 .1 沉井简介 .................................................................................................................. 1 1 .1 .1 沉井规模与构造 ............................................................................................ 1 1 .1 .2 沉井所选用的材料 ........................................................................................ 1 1 .1 .3 钢筋混凝土保护层 ........................................................................................ 1 1 .2 工程地质状况简介 .................................................................................................. 2 1 .2 .1 地形地貌及地下水 ........................................................................................ 2 1 .2 .2 地层特征 ........................................................................................................ 2 1 .2 .3 沉井井壁摩阻力参数 .................................................................................... 3 1 .2 .4 地质条件对沉井所产生的影响因素 ............................................................ 3 2 ．施工部署 ........................................................................................................................ 4 2 .1 沉井的主要施工方法选择 ...................................................................................... 4 2 .1 .1 沉井方法：采用排水下沉和干封底的工艺技术 ........................................ 4 2 .1 .2 降水方法：井外真空深井泵与井内明排水相结合 .................................... 4 2 .1 .3 制作与下沉方法：两节制作、两次下沉 .................................................... 5 2 .1 .4 沉井底部地基加固方法：压密注浆 ............................................................ 5 2 .2 沉井工艺流程 ....................................................
