MECHANICAL CHARACTERISTICS OF UNSYMMETRICAL SUPPORT STRUCTURE OF SHALLOW-BURIED BIAS MULTI-ARCH TUNNEL
WANG Yaqiong1，ZHANG Shaobing1，2，XIE Yongli1，LAI Jinxing1
(1. Shaanxi Provincial Major Laboratory for Highway Bridge and Tunnel，Chang¢an University，Xi¢an，Shaanxi 710064，China； 2. Xi¢an Metro Co.，Ltd.，Xi¢an，Shaanxi 710055，China)
Abstract：According to the issue of unsymmetrical force in the construction of shallow-buried bias multi-arch tunnel and the actual situation of Yaoshuixia multi-arch tunnel，the mechanical characteristics of shallow-buried bias multi-arch tunnel are analyzed using finite element method and in-situ monitoring，and the support structure is optimized with unsymmetrical design methods. The results indicate that the unsymmetrical design and construction of the shallow-buried bias multi-arch tunnel are feasible；the pressure on earlier constructed cavern of the multi-arch tunnel is greater than that of the later one，and the relation between this result and the bias condition is not obvious；the pressure on surrounding rock of shallow-buried bias multi-arch tunnel should be considered according to the radial load of the round cavern. Therefore，when designing and constructing the similar shallow- buried bias multi-arch tunnel，the construction sequence should be paid attention to，and the unsymmetrical design of the structure is feasible.
