With the rapid development of urban underground space, the depth of working shaft has been gradually becoming deeper to accommodate the underground construction needs. The existing studies for earth pressure distribution of shafts are mainly focused on sandy soils within 30 m. There is a strong need to investigate the earth pressure distribution on deep shafts (more than 30 m) in complicated soil conditions using centrifuge modelling to fill the knowledge gap and provide experimental basis for design. In this paper, geotechnical centrifuge modelling was used to investigate the earth pressure distribution along deep circular shaft structures (with a depth of 100 m) in composite geological strata. Three centrifuge tests on model shafts in layered ground with different thickness of clay and sand were carried out, respectively. Drainage method was used in the experiment to simulate the unloading effect caused by excavation of soils inside the shaft model. The earth pressure distributions along the shaft lining before and after the excavation were investigated. The results were analysed and compared with other existing earth pressure theories. This research provides valuable insights for earth pressure distribution for design of circular deep shafts (e.g. 100 m) in composite geological strata.

随着城市地下空间的快速发展，工作井的深度已逐渐变深，以适应地下建筑的需要。现有的竖井土压力分布研究主要集中在30 m以内的砂土上。迫切需要使用离心模型来研究复杂土壤条件下深井（30 m以上）上的土压力分布，以填补知识空白并为设计提供实验依据。本文采用岩土离心机模型研究了复合地质层中沿深圆形竖井结构（深度为100 m）的土压力分布。在不同厚度的粘土和沙子的分层地面上，分别对模型井筒进行了三个离心机测试。试验中采用排水法模拟了竖井模型内土方开挖引起的卸荷效果。研究了开挖前后沿井壁衬砌的土压力分布。对结果进行了分析，并与其他现有的土压力理论进行了比较。这项研究为复合地质层中圆形深井（例如100 m）的设计中的土压力分布提供了宝贵的见识。