砂卵石强渗透地层防渗墙成墙技术

Technology of forming cutoff walls in sand pebble strong permeable stratum

本文以广州市增城区正果拦河坝重建工程防渗墙成墙实例为基础,介绍了在砂卵石强渗透地层环境中,针对防渗墙试验槽段因渗透压力大,泥浆被稀释导致成槽过程塌陷返工、影响成墙进度的问题,采取施打拉森钢板桩止水、增设大功率水泵降排水等措施以降低渗透压力,使防渗墙成墙的质量、进度均达到了设计要求,成功解决了砂卵石强渗透地层防渗墙塌陷返工的技术问题。

The paper is based on the example of cutoff wall formation in Guangzhou Zengcheng District Zhengguo Barrage Reconstruction Project. The problems of collapse and rework during grooving process and influence on wall formation progress in the cutoff wall test groove section due to high seepage pressure and diluted cement slurry in sand pebble strong permeable stratum environment are introduced. The following effective measures are adopted: water sealing by drilling lassen steel sheet piles and water drainage by adding high-power water pump to reduce seepage pressure. The quality and progress of forming the impervious walls meet the design requirements, and the technical problems of collapse rework of impervious walls in sandy pebble strong permeable stratum are successfully solved.