Analysis on interaction between tunnel-type anchorage in suspension bridge and highway tunnel
ZHU Yu~(1,2),WEI Jun~1, LI Hao~1, YANG Man-juan~1(1. Civil Engineering Department,Huazhong University of Science & Technology, Wuhan 430074, China;2. China 2nd Highway Reconnaissance, Design and Research Institute, Wuhan 430052, China)
s:The stress state in anchorage zone is very complex while tunnel-type anchorage lies above highway tunnel. It is important to study the interaction between anchorage and highway tunnel. Full-scale model test is hard to carry out, so numerical analysis becomes the best choice. In this paper, the first tunnel-type anchorage used in long span suspension bridge of China is studied. Based on consideration of rock mass parameters from tests and other factors, the three-dimensional (3D) elasto-plastic analysis has been performed to simulate the complete sequence of constructing progress, including highway tunnel excavation, tunnel-type anchorage construction, concrete casting in-situ, anchorage prestressing, main cable installation, etc. Surrounding rock and anchorage body are modeled as eight-node, 3D solid elements, whereas shot concrete and lining are modeled as four-node, 3D shell elements. Geostatic state of complex geometric structure is established by reading initial stress from data file. It can be seen from the results that if a proper distance between the anchorage and the tunnel has been chosen, their interaction is not obvious; the construction sequence that the anchorage is excavated after the tunnel is reasonable by comparing vertical displacement caused by the tunnel construction and designed cable force; the construction of anchorage has little influence on displacement of surrounding rock of tunnel. The results could provide reliable basis for the design and construction of the bridge and tunnel.