某超深基坑开挖深度达到25m,基坑围护体系采用“两墙合一”的地下连续墙,基坑工程地处高水位、深厚砂土地层,且周边环境条件复杂。分析了地下连续墙作为主体结构的设计方法,包括地下连续墙作为主体结构的布置方式、地下连续墙的接头及防水设计、地下连续墙与主体结构构件的连接及防水设计等,并对地下连续墙的内力计算方法进行了分析。工程实施的结果表明“两墙合一”的地下连续墙具有较好的可靠性和经济性。 An ultra deep foundation pit excavation depth of 25m, foundation pit enclosure system using “two walls together ” underground diaphragm wall, foundation pit project is located in high water level, deep sand formation, and the surrounding environmental conditions are complex. The design method of underground continuous wall as the main structure is analyzed, including the arrangement of underground continuous wall as the main structure, the joint and waterproofing design of underground continuous wall, the connection and waterproof design of underground continuous wall and main structural member, The internal force calculation method of the wall is analyzed. The results of the project implementation show that the “two walls together” underground diaphragm wall has good reliability and economy.