浅水压集水坑防水处理工艺探讨
浅水压集水坑防水处理工艺探讨
摘要:筏板基础中集水坑在浅水压的情况下, 防水层施工是个难点, 施工过程中通过预留降水井,人工定时降水控压,保证垫层砼的浇筑成型;卷材防水施工时预留降水井位置后做;筏板砼具备浇筑条件后,在降水井内设置导水钢套管并通过自吸泵降水,降水井其余部位在抽水间隙用抗渗砼灌实,将原有卷材搭接后收口在钢套 管止水环上,立即开始集水坑内砼浇筑;砼浇筑7天后,用膨胀、防水材料把导水钢套管堵死。此处工艺措施简单、成本低、效果好。
关键词:集水坑;浅水压;降水井;钢套管;防水。
Abstract: the sump pressure in the shallow water, the raft foundation under the waterproof layer is difficult, reserved dewatering well construction process, artificial timing of precipitation controlled pressure cushion concrete pouring molding; waterproof membrane construction reserved the position of dewatering well do; the raft concrete with pouring conditions set in precipitation wells hydraulic conductivity steel casing and the remaining parts in the pumping gap impermeability of concrete irrigation real self-priming pump precipitation, precipitation wells, the original volume shut up in a steel casing seal ring material lap immediately began catchment pit concrete pouring; concrete pouring 7 days after the expansion, the waterproof material steel casing of the hydraulic conductivity blocked. Here technology is simple, low cost measures, to good effect.Keywords: sump; shallow pressure; dewatering well; steel casing; waterproof.
引言
随着城市的大开发、土地资源的日趋紧张, 深基坑工程的施工日益增多,鄂尔多斯大兴国际商都工程开挖深度13.8m 。由于地下水埋藏地表下6.2~8.7m,属层间水和基岩裂隙水,土方开挖时采用预置泻水管进行疏导明排,土方挖至基底标高后,四周设置排水明沟降水,当集水坑和塔吊基础等开挖超过排水沟底标高后出现明水压,如何控制水压,及如何控制、引导地下水、如何减缓地下水压、保证防水层的施工,和找到具体操作性强且施工简单和节约成本是本文要解决的问题。
1工程概况
鄂尔多斯大兴国际商都工程,位于鄂托克西街南侧,团结路与松山路之间。工程建筑面积为213474.98m2,地下部分为5万多平方米。地下三层,地上十六层。分三段布局,结构形式为框架—剪力墙结构,基础形式为钢筋混凝筏板基础、筏板厚度为800mm ,共有包括塔吊基础和电梯井在内的积水坑等17个。