Abstract:

A threedimensional finite element model is established to study the settlement mechanism of the city wall in Xi’an, with a shield tunnel on Line 1 of Xi’an Metro crossing underneath the city wall of Chaoyang Gate and Chaoyang Gate openings as the background. Force analysis is made on the ancient city wall and the settlement of the city wall and the ground nearby is predicted. Reinforcement measures are determined on basis of the analysis results. The numerical simulation and the engineering practice show that: 1) Under the condition of the optimized construction methods, route locations and route depths, the reinforcement measures taken can bring the settlement and deformation of the city wall under control; 2) The numerical simulation results are basically consistent with the regularity of the settlement of the city wall, although they are some conservative; 3) The settlement control standard proposed, which can meet the requirements of the tunnel construction and the protection of the cultural relics, can be used as reference for similar projects in the future.

Key words: Xi’an Metro, Xi’an city wall, shield tunnel, numerical simulation, settlement standard