Application of fabricated corrugated steel plate in subway tunnel supporting structure

Abstract

This study investigated the mechanical behavior of fabricated corrugated steel plate during tunnel construction period and the influence on surrounding ground settlement, aiming to provide insight into tunnel support structure design and construction. To this end, a reality engineering case (e.g., Beijing Metro Line 27) and numerical simulation were used to analyze the mechanical characteristics of the corrugated steel plate supporting structure and evaluate the safety of the prefabricated supporting structure. The results showed that the maximum ground subsidence is located 11 m away from the shaft, and the corresponding subsidence value is − 2.55 mm. In addition, the tunnel construction has slight impact on ground subsidence. With the increase of distance from the shaft, the land subsidence first increased and then presented a reduction trend. The deformation characteristics of convergence and arch crown settlement of tunnel support structure exhibited “bell shape” distribution, which was closely related to the constraints of shaft and blocking wall at both ends of tunnel support structure. Furthermore, it can be concluded that the prefabricated corrugated steel plate as a tunnel support structure received less stress and deformation, which indicated the corrugated steel plate had sufficient strength to restrain the deformation of the surrounding rock. Comparing the monitoring data and the numerical simulation results, it can be observed that the results obtained by numerical simulation were consistent with the field monitoring data, which meant that the numerical model can predict the construction process of the assembly tunnel support structure.