超深止水帷幕在武汉长江Ⅰ级阶地冲积相基坑支护工程中的选取和应用

Selection and Application of Extra-deep Anti-seepage Curtain in Foundation Pit Supporting Engineering on First Terrace Alluvial Facies of Yangtze River in Wuhan

基坑支护工程中常选用CSM、TRD、三轴搅拌桩工法施作超深止水帷幕。通过对比CSM、TRD、三轴搅拌桩工法的优缺点,并以武汉长江Ⅰ级阶地冲积相区域的三个邻近基坑工程为例,介绍CSM、TRD水泥土搅拌墙及三轴搅拌桩止水帷幕的选取方法和应用效果。分析认为,在实际工程中应综合成桩深度、设备高度所要求的垂直条件、土层情况、施工成本、基坑开挖深度、降水需要和落底情况等因素,优选CSM、TRD水泥土搅拌墙或三轴搅拌桩止水帷幕,方能达到良好的基坑止水效果和安全性、经济性与效率的统一。研究成果可为具有类似工程地质和水文地质条件的基坑支护工程止水帷幕的设计提供参考。

CSM,TRD and three-axis mixing pile construction method are often used to construct extra-deep anti-seepage curtain in foundation pit supporting engineering.By comparing the advantages and disadvantages of CSM,TRD and three-axis mixing pile construction methods,and taking three foundation pit projects on first terrace alluvial facies of Yangtze River in Wuhan as an example,the selection method and application effect of CSM cement-soil mixing wall,TRD cement-soil mixing wall and three-axis mixing pile anti-seepage curtain are introduced.The analysis shows that in practical engineering,the anti-seepage curtain of CSM cement-soil mixing wall,TRD cement-soil mixing wall or three-axis mixing pile should be optimized by considering the factors such as pile depth,vertical condition required by equipment height,soil condition,construction cost,foundation pit excavation depth,precipitation requirement and bottom condition,so as to achieve good waterproof effect of foundation pit and safety,economy and efficiency.The research results can provide reference for anti-seepage curtain design of foundation pit supporting engineering with similar engineering geological and hydrogeological conditions.