Numerical analysis of harmful effects on highway tunnel and bridge crossing the mined-out regions and its application

摘要

The three-dimensional computation model was built by using MIDAS/GTS finite element program and FLAC3D technique based on the Kangjiagou bridge-Miaoliang tunnel project which is crossing the mined-out regions in Liulin section of QingdaoYinchuan highway. The deformation responses of the ground surface, the tunnel lining and bridge structure, and as well as their structural forces are analyzed as the following sequence of operations: the mining process step-by-step was performed corresponding to the years, and then the grouting treatment technology was carried out after mining coal in Kangjiagou, next, Miaoliang tunnel was excavated and Kangjiagou bridge was constructed. The surface deformations under different working conditions were revealed, and the ground subsidence basin characteristics were analyzed. Also, the deformations and forces of key bearing parts of the tunnel lining and bridge structure were predicted in order to guide the engineering design and construction. The above-mentioned results have important theoretical meaning for guiding the practice of goaf grouting and supporting of tunnels and bridges to meet the requirements of strength, stiffness and stability of tunnels and bridge structures.