A Study On Settlement Calculation And Damage Evaluation Of Shield Tunnel Crossing Old Bungalow Areas

This paper, the research rely the Beijing Subway Line8, focusing on analysis of numerical method of shield tunneling and the differential settlement from the method, by the way analysis the damage assessment method of the old Bungalow areas. This paper provide a reference for shield tunnel crossing the old Bungalow areas in the closed soil situation.In order to reaserch the numerical method with shield tunneling constraction, and the the differential surface settlement response by setting the control indicators of the ground loss rate, the volume loss control method be used combined with the measured data to make a inverse-evolution analysis. The reaserch illustrates the stress release with unequal-step method the basis to achive the numerical simulation by using the volume loss control method. While the measured data throgh the inverse-evolution analysis presented rational expression formula for stress release control. Numerical analysis shows that the law has the same performance between the measured data and the volume loss control method in FLAC3D, the reasualt is good enough to analyze the characteristics of the surface differential settlement. Meanwhile, analysis the law of differential settlement under the one-line excavation and the excavation sequence of the double-line excavation and the law of differential settlement with architectural foundation stiffness.By putting masonry as consists of block, mortar and bond between the two with a three-phase composite materials, then using the discrete element method to established masonry numerical model to analyze masonry structural deformation and the law of cracking under the condition of the differential settlement with energy principle. Study illuminates the law of cracks development and structural damage cloud of masonry under the differential settlement, through energy principle analysis, proposed the static energy peak indicators of the masonry structure under differential settlement. This part explanation the numerical conclusions can predict the safety of masonry structure and provides a new technology path for masonry structure damage analysis.