青草沙水库围堤地基液化危害分析与治理研究

Research on the hazard analysis and treatment technology of sandy soil liquefaction in Qingcaosha reservoir cofferdam

青草沙水库是我国目前最大的江心水库,是上海以长江为原水的水质最好规模最大的饮用水与城市供水水源地,为上海“十一五”重点工程。青草沙地区浅部存在液化砂性土层,需要对围堤地基的液化危害土层进行治理,以确保工程的施工与运行安全。本文根据液化判别结果,对液化等级进行了分区,并对液化土层进行统计分析,针对各堤段的特点、位置、液化等级和液化土层分布,对各种常用的液化危害治理方法进行综合比较研究,推荐了最经济最适宜的液化危害治理方法,对青草沙水库工程设计和安全运行起到了积极作用。事实证明,这些治理方法不仅经济效果好,而且围堤的地基液化危害和渗漏问题也得到了很好的改善,可为同类项目提供重要借鉴。

The Qingcaosha Reservoir is the largest reservoir in the middle of Yangtze River in China.It is the largest source of drinking water and urban water supply in Shanghai,with the best quality of raw water.It is the key project of Shanghai's“11th five-year plan”.A liquefied sandy soil layer exists in the shallow part of the Qingcaosha area.Therefore,it is necessary to treat the liquefied harmful soil layer of the embankment foundation to ensure the safety of the construction and operation of the project.The liquefaction grade was divided,and the liquefied soil layers were statistically analyzed according to the liquefaction discrimination results from this study.Based on the characteristics,location,liquefaction grade,and distribution of liquefied soil layers of each embankment section,various liquefaction treatment methods have been compared and studied,and the most economical and appropriate liquefaction treatment methods have been suggested.The suggested treatment methods have played an important role in the engineering design and safe operation of the Qingcaosha reservoir.Research has shown that these treatment methods not only have good economic effects but also resolve the liquefaction hazards and leakage problems of the embankment,which can provide a reference for similar projects.