Abstract:In order to study the force mechanism of system bolts in the loess tunnel with large sections, take the Q3 sandy loess in northwest area, according to the basic principles of centrifugal test in loess tunnel, take similar than the value of g is 80, and use organic glass as the similar material simulating primary support of the tunnel structure. Set up 0m, 3.5m, 6m, 8m bolts comparison model centrifugal experiment to study. Finally it is concluded that , after the primary support closed and system bolt construction, system bolt length increased from 0 m to 8m, formation and primary support deformation reduced and the ratio increased, vault subsidence reduced by 11.67%, settlement of the arch foot by 14.48%, the surface subsidence by 7.12%, peripheral convergence by 17.73%. But due to system bolt construction would make primary support closed time increased from 7 d to 10 d, increased by 42.9%, and the tunnel vault subsidence increased by 24.2%. Therefore, the overall effect of the system bolt is not obvious, system bolt length increased to 8m, vault subsidence still increased by 12.55%, the primary support closed time increased by 42.9%. In the loess tunnel with large sections, the control effect of system bolt is not obvious to tunnel deformation, increasing system bolt length the effect is still not obvious, suggest to cancel system bolt.
孟德鑫 谭忠盛 王秀英. 大断面黄土隧道锚杆作用机理的离心试验研究[J]. 土木工程学报, 2017, 50(S1): 36-41.
Meng DeXin Tan Zhongsheng Wang Xiuying. Centrifugal experimental study of force mechanism of system bolts of large section loess tunnel. 土木工程学报, 2017, 50(S1): 36-41.