基坑提前排水围堰渗流稳定及排水策略研究  

Research on Seepage Stabilization and Drainage Strategy of Foundation Pit Advance Drainage Cofferdams

作　　者：吴都督[1] 赵银超[1] 曾伟 向金虎 WU Du-du;ZHAO Yin-chao;ZENG Wei;XIANG Jin-hu(Sinohydro Engineering Bureau 8 Co.LTD,Hunan Province,Changsha 410004,Hunan Province,China;Huaneng Langcang River Hydropower Inc.,Yunnan Province,Kunming 650206,Yunnan Province,China;State Key Laboratory of Water Resources Engineering and Management,Wuhan University,Wuhan 430072,Hubei Province,China)

机构地区：[1]中国水利水电第八工程局有限公司,湖南长沙410004 [2]华能澜沧江水电股份有限公司,云南昆明650206 [3]武汉大学水资源工程与调度全国重点实验室,湖北武汉430072

出　　处：《中国农村水利水电》2024年第5期243-248,共6页China Rural Water and Hydropower

基　　金：国家自然科学基金资助项目(50809052)。

摘　　要：围堰渗流及边坡稳定关系到围堰自身稳定以及基坑能否及时形成干地施工条件,极大影响到主体建筑物的工期。依托于澜沧江TB水电站围堰施工与基坑排水工作,对围堰防渗墙各施工阶段基坑水位骤降条件下的堰体渗流稳定与边坡稳定性进行了研究。结果表明:随着防渗墙的施工逐步完成,围堰体浸润线的再次稳定用时逐步减小,且基坑内外水位差更大的条件下浸润线稳定用时更长;在围堰防渗墙处于一期槽施工完成二期槽泥浆固壁条件下,若能控制基坑单次水位骤降不超过0.9 m,则堰体边坡能保持稳定,此时可允许基坑提前排水。在此基础上,对TB水电站基坑提前排水策略及方案进行了研究。研究结果可为类似工程提供参考。Cofferdam seepage and slope stability are related to the stability of the cofferdam itself and whether the dry construction conditions can be formed in time,which greatly affects the construction period of the main building.Based on the cofferdam construction and foundation pit drainage of TB hydropower station in Lancang River,ABQUAS and SLIDE software were used to study the seepage stability of cofferdam body and slope stability under the condition of sudden drop of foundation pit water level in each construction stage of the cofferdam cut-off wall.The results show that:with the gradual completion of the construction of the cut-off wall,the stabilization time of the seepage line of weir body is gradually reduced,and the seepage line stabilization time is longer under the condition of greater water level difference between the inside and outside of the foundation pit;under the condition that the construction of the phase 1 trench of the cut-off wall is completed and the phase 2 trench is in the process of slurry retaining wall,if the water level plunge in pit can be controlled to not exceed 0.9 m per process,the cofferdam slope can remain stable,and at this time the foundation pit can be allowed to advance drainage.based on the result,the strategy and program of advance drainage of tb hydropower station pit were studied.the results of the study can provide reference for similar projects.

关 键 词：围堰 渗流稳定 边坡稳定 基坑排水 

分 类 号：TV551.41[水利工程—水利水电工程]