Study on Influence Evaluation and Control Measures of Open-cut Construction of Ramp Tunnel Adjacent to Bridge Piers

Abstract

Improper control of tunnel structure adjacent to bridge piers in soft soil area will lead to structural deformation and traffic unsafety. In view of the engineering difficulties in the construction of the near-bridge-pier interchange ramp between Shenzhen-Zhongshan Bridge and Guangzhou-Shenzhen Expressway along Yangtze River, numerical simulations are carried out based on analyses of the position relationship and geological conditions. During ramp tunnel construction, the maximum horizontal displacement of the diaphragm wall structure is 19 mm, and the maximum horizontal displacement of the bridge pier, located in the middle of the foundation pit, is 7.4 mm. The vertical uplift displacement at the bottom of the foundation pit and that at the top of the open-cut tunnel structure is large, about 5.3 mm. In view of the analysis results, control measures such as soil reinforcement treatment and timely lateral support are introduced to ensure construction safety and provide reference for similar projects.