ABSTRACT
The pipe-roof method is an increasingly popular pre-construction soil support system for underground space development for its superior safety. However, the traditional pipe-roof method has a low load-bearing capacity and requires the erection of a large number of temporary supports, resulting in a complex construction sequence. Accordingly, a novel pipe-roof method is proposed, which is suitable for ultra-shallow buried large-span subway station construction. This investigation establishes three-dimensional finite-difference models and describes complementary theoretical analysis to explore the development of pipe-roof and ground deformation. The results show that the stage of removing the guideway wall and constructing the concrete slab is the key stage to control the surface settlement. The ground deformation theoretical predictions are shown to be in good agreement with the numerical simulation results, indicating the proposed model is closed-form and suitable for routine use in design.
