Structure Deformation and Stress Analysis for Metro Station Constructed in Combination with Municipal Bridge

Objective When metro station is constructed in combination with a municipal bridge, the station structural stress stage can be divided into pre-bridge and post-bridge parts. At present, there is a lack of systematic summary and analysis of the stress characteristics of the metro station structure in these two stages. Therefore, it is necessary to analyze the deformation and stress characteristics of the metro station structure during the two stages of combined station-bridge construction.

Method Based on the actual engineering project and referring to a certain standard metro station, a load-structure calculation model is established. Focusing on structural components such as the station roof slab, roof longitudinal beam and transfer beam, numerical simulation and calculation are carried out using MIDAS GEN software. The structural stress and deformation characteristics of the metro station constructed in combination with a bridge are comparatively analyzed between the pre-bridge and post-bridge stages, according to the standard section and the end-shaft section respectively.

Result & Conclusion  The bridge load and transfer beam may alter the stress state of the roof slab and roof longitudinal beams of station structure, with the primary influence range concentrated on the spans adjacent to both sides of the transfer beam, with relatively minor effect on the intermediate spans. For the roof slab of a combined station-bridge structure, except for the side supports of adjacent spans—which should have reinforcement strengthened according to the internal forces during the post-bridge stage—the transverse reinforcement in other areas can be done following the standard station design. During the pre-bridge stage, the roof slab on both sides of the transfer beam experiences larger longitudinal bending moments and shear forces; therefore, it is recommended to set haunches between the transfer beam and the roof slab and to strengthen the longitudinal reinforcement of the roof slab in adjacent spans along the bridge. The spatial stress in the end-shaft section is significant, due to the bridge load, the pier-under columns may undergo large deformations, causing tension on the roof slab at the column support positions and the lower part of the longitudinal beams, which may lead to cracking or damage. Hence, bridge piers should be arranged to avoid the end-shaft area.