Abstract：The Jiangtai metro station of Beijing Metro line 14 is constructed by enlarging the large-diameter shield tunnel with the mining method. A CRD (cross diaphragm) construction scheme of enlarging the shield tunnel is put forward in the preliminary design. By considering the geological conditions and environmental conditions, the problems of the CRD scheme are analyzed and a PBA method (Pile-Beam-Arc method) is proposed. In order to control the ground settlement and the influence on the surrounding environment, the dewatering scheme is replaced with deep the hole grouting in the excavation face. Three-dimensional finite element models are used to simulate the ground-structure interactions. The numerical results show that the structural stress state varies frequently in the enlarging process. Due to excavation of the two sides of middle pilot tunnels and dismantling of the K segment, the stress of the primary lining of the middle pilot tunnel increases dramatically. The primary lining parameters and the excavation method for the two sides of the middle pilot tunnels are adjusted according to the analysis results. Although the stress state of the segments shifts from compressive stress to tensile stress in the dismantling process of both sides of the small segment, the overall stability is not affected. The maximum principal stress in the middle partition wall appears after dismantling both sides of the small segment. The calculation results show that the construction optimization scheme is feasible and the structural safety can be guaranteed.
李习伟 郑昊 王全贤. 基于大直径盾构隧道扩挖地铁车站结构安全分析[J]. 土木工程学报, 2016, 49(9): 96-102.
Li Xiwei Zheng Hao Wang Quanxian. Safety analysis for metro station constructed by enlarging large diameter shield tunnel with mining method. 土木工程学报, 2016, 49(9): 96-102.
