Integrating Geotechnical Engineering and Finite Element Analysis in Urban Tunnel Construction: Case Study of Zhongshan Road Station on Hohhot Metro Line 2

Abstract

The expansion of Metro Line 2 with the addition of Zhongshan Road Station in Hohhot presents a paradigm of urban engineering that merges infrastructure growth with the conservation of extant utility systems. This study examines the station's construction, located at a critical junction, which includes a novel straight-wall arch tunnel in close proximity to essential gas pipelines. The core of this paper explores the geotechnical challenges, the application of advanced construction techniques, and particularly the strategic use of grouting for soil stabilization. The employment of Midas GTS NX (2020) for finite element numerical simulation analysis facilitated a thorough investigation of soil dynamics and the interaction with gas pipelines, utilizing the Mohr-Coulomb model. This research also evaluates the impact of different grouting reinforcement approaches on pipeline settlement through a series of controlled simulations. The results demonstrate the significance of grouting methods and their scope in reducing pipeline settlement, where full-section grouting is most effective, but semi-section grouting within a 2.0 m range provides a viable, resource-efficient alternative. The findings of this study offer practical guidance for urban tunnel construction near sensitive infrastructure and emphasize adaptable grouting techniques to ensure the integrity of new and existing structures.