装配式地下连续墙设计施工技术研究

Research on the Design and Construction Technique of Prefabricated Diaphragm Walls

研究目的:现浇地下连续墙是深基坑工程中常用的围护形式,但是在特殊地层和施工环境下,传统工艺经常存在塌槽,现场水下现浇混凝土质量不易控制,接头夹泥、漏水,成槽泥浆排放存在环保问题等缺陷。装配式地下连续墙技术是对传统地连墙设计和施工技术的重大改进,大大减小工程风险,提高施工速度,对城市地铁超深基坑施工安全具有重大意义。研究结论:(1)装配式地连墙在工厂预制,具有墙体质量好、占地面积小、施工速度快、环保等特点;(2)通过数值模拟与试验验证了套筒锚接的接头形式满足受力要求;(3)配合预搅拌成槽、移动式墙幅拼装插入设备拼装墙幅,以及后期的墙缝注浆止水,永临结合形式的围檩配合内支撑体系,形成系统的装配式地下连续墙工艺;(4)装配式地连墙质量可靠、施工工艺简单、配套设备研发齐全、技术经济优势明显,可在地铁超深基坑明挖施工中推广应用。

Research purposes: The diaphragm wall is commonly used method in the deep excavation projects.However,the tradition cast-in diaphragm wall construction occupies large area. The wall structure is constructed under water cast-in-place concrete,so the quality of the concrete is not easy to control,and some defects appears such as joints muddy, water leakage, and the bentonite slurry discharge has environmental problems. The assembled underground continuous wall technology is a great improvement to the design and construction technology of the traditional ground-connecting wall,which greatly reduces the engineering risk and improves the construction speed,which is of great significance to the construction safety of the ultra-deep foundation pit of urban subway.Research conclusions:( 1) The assembled wall is prefabricated in the factory,which has the characteristics of good wall quality,small area,fast construction speed,environmental protection and so on.( 2) Numerical simulation and experimental results show that the joint form of sleeve anchor joint meets the stress requirements.( 3) With the trench cutter and the mobile diaphragm assembling and inserting device to construct the wall,and joints grouting,the permanent and temporary combination wale and the inner support will form the system of the assembled prefabricated diaphragm wall.( 4) The prefabricated diaphragm walls with reliable quality,simple construction schedule,complete equipped devices and obvious advantage of technology and economy,already have the condition to practice and apply.