以北京地下直径线工程4#竖井为例，对在砂卵石地层中进行超深地下连续墙的设计施工，并从复杂的地质、周边环境、工程难点和可能出现的问题进行分析，通过对横幅的设置、施工顺序、混凝土灌注、成槽的质量控制等方面采取的一系列技术措施，为连续墙成功施作提供了保证。

Taking No.4 vertical shaft of Beijing Rail Transit Line as works case，this paper makes analysis on the complicated geology，environment，difficulties and possible problems in the design and construction of extradeep diaphragm walls in sandpebble ground，and describes the technical measures taken in such aspects as the division of the diaphragms, construction sequence， concrete casting and quality control of channel cutting so as to ensure the successful construction of the diaphragm walls.