STUDY OF SAFETY THRESHOLD OF SURROUNDING ROCK DAMAGE DEGREE OF ANCHORAGE TUNNEL FOR SUSPENSION BRIDGE BASED ON DISPLACEMENT RULE
(1. Nanning Rail Transit Co.，Ltd.，Nanning，Guangxi 530000，China；2. Department of Geotechnical and Tunnelling Engineering，Changsha University of Science and Technology，Changsha，Hunan 410076，China)
Abstract：Based on the blasting excavation in tunnel-type anchorage of Aizhai suspension bridge，the characteristic curves of displacement and rock damage degree D of tunnel-type anchorage are obtained by numerical analysis according to the finite element models established under different damage degrees. The results show that the anchorage slides along the direction of cable tensile forces and uplifts vertically under cable tensile forces. There are two inflection points in the curve of displacement and rock damage degree when D = 0.1 and 0.4. When D = 0.2，the curve is a typical mono-peak one. Displacement field of surrounding rock nearby the anchorage has uniform distribution；and the efficiency of sharing and transferring cable forces by anchorage tunnel surrounding rock is higher. When D≥0.3，the curve of displacement and rock damage degree transforms into a typical double peak curve. Displacement field of the anchorages exhibits a mutual independence to a certain extent，and the displacement contours of the anchorages are separated with each other when the cable being overloaded. When D≥0.6，anchorage displacement increases greatly and its field separates completely. Based on the above conclusions，D = 0.2 and 0.6 can be considered as the safety threshold of damage degree of surrounding rock Dcr and critical value of anchorage failure Dur，respectively.
黎高辉1，2，吴从师2，邓泷波1. 基于变位规律的悬索桥锚碇隧道围岩损伤度安全阈值研究[J]. 岩石力学与工程学报, 2010, 29(S2): 3633-3640.
LI Gaohui1，2，WU Congshi2，DENG Longbo1. STUDY OF SAFETY THRESHOLD OF SURROUNDING ROCK DAMAGE DEGREE OF ANCHORAGE TUNNEL FOR SUSPENSION BRIDGE BASED ON DISPLACEMENT RULE. , 2010, 29(S2): 3633-3640.
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2010, Vol. 29 
