东平湖围坝加固方案研究

Study on Strengthening Scheme for Box Dam of Dongping Lake

东平湖围坝加固工程，最初的截渗墙加固方案，是按墙体深度22 m为界，深度在22 m以内的堤段采用深层水泥土搅拌桩截渗墙，墙体深度在22～27 m的堤段采用振冲防渗板截渗墙，截渗墙深度超过27 m的堤段采用混凝土截渗墙。在施工过程中，采用的振冲防渗板截渗墙和混凝土截渗墙施工较为困难，施工造价高，尤其在有深浅不一的地下障碍物以及钙质结核层时很难保证施工的正常进行。为此对截渗墙深度超过22 m和地下有障碍物的堤段进行优化。通过分析研究，采取深层水泥土深层搅拌与高喷相结合水泥土截渗墙相结合方法，解决了黄河堤防水泥土搅拌桩不能处理深层、不良地基、适应能力差和高摆喷截渗墙成本高的难题。且施工工艺成本低，取得较好的经济效益。

The preliminary strengthening scheme for box dam of Dongping Lake,taking the wall depth of 22m as the boundary,proposed a deep soil cement mixing pile cut-off wall for the embankment section with wall depth within 22m;a vibroflotation anti-seepage plate cut-off wall for the embankment section with wall depth between 22~27m;and a concrete cut-off wall for the embankment section with wall depth over 27m. During the construction, it was rel-atively difficult in construction with vibroflotation anti-seepage plate cut-off wall and concrete cut-off wall, and the construction cost was high;even normal construction could not be guaranteed where irregular underground obstacles and calcareous concretion stratum were encountered. Thus the embankment section with the cut-off wall depth over 22m and with underground obstacles should be optimized. According to analysis and study, the soil cement cut-off wall by soil cement deep mixing and high pressure jet grouting, which brings low construction cost and better econom-ic benefits and leads to a solution of such problems of Yellow River embankment as failure to handle the deep stratum by the soil cement mixing pile, unfavorable foundation, poor adaptability and high cost for high pressure swing jet grouting cut-off wall,is determined to be applied.