Seismic Stability and Sustainable Performance of Diaphragm Walls Adjacent to Tunnels: Insights from 2D Numerical Modeling and Key Factors

Abstract

The seismic performance of diaphragm walls adjacent to tunnels plays a pivotal role in ensuring the stability of underground infrastructure. This article presents an extensive investigation into the seismic behavior of such diaphragm walls through advanced two-dimensional (2D) numerical modeling. The primary objective is to establish the accuracy and reliability of the numerical model by comparing its results with a reference case history from Tianjin, China. Following successful validation, the study employs rigorous two-dimensional (2D) numerical analyses to examine the response of the diaphragm wall to seismic events while considering crucial factors. These factors encompass the dynamics of pore water pressure, the diverse acceleration histories of earthquakes, varying tunnel positions, and their combined influence on the horizontal displacement of the wall. From our findings, we can conclude that earthquake duration has a more substantial impact on displacement and wall deformation compared to peak ground acceleration (PGA). Longer earthquake durations are associated with greater displacement. In dynamic analyses, the presence of water diminishes soil displacement and concentrates plastic deformation points. The distance between the tunnel and the diaphragm wall significantly affects wall displacement and deformation. The effective distance is approximately 10 m. Our findings can inform better design and construction practices to enhance the stability of underground infrastructure in seismically active regions.