Model test of new-type support structure for segment lining combined with compressible ceramic
Hu Xiongyu 1,2 He Chuan 1,2 Yang Qinghao 1,2 Cao Songyu 1,2
1. Key Laboratory of Transportation Tunnel Engineering of the Ministry of Education, Southwest Jiaotong University, Chengdu 610031, China;
2. School of Civil Engineering, Southwest Jiaotong University, Chengdu 610031, China
Abstract:Suitable for tunneling in deep stratum using TBM method, a yielding technology of segment lining combined with compressible ceramic is proposed. Based on the project of deep, long-distance inclined shaft engineering constructed by TBM method in Taigemiao Mine, model tests is used to study the yielding effects of ceramic and crushed stone compressible layer from the bending moment, axial force, deformation and failure characteristic of segment lining. The yielding mechanism is revealed according to the compressible deformation path and the moving characteristics of particles in compressible layers. The research results indicate that the honeycomb structure in ceramic can offer high compressibility, thus its compression rate is 10 times the crushed stone. The yielding effect of ceramic compressible layer is better than that of the crushed stone. Under unequal compressive stress, the crushed stone compressible layer would reduce the resistance coefficient in negative bending area of segment lining to a certain extent, causing larger negative bending moment and increasing the number and width of cracks in negative bending area. Due to different shape and internal structure, the ceramic and the crushed stone results have different yielding effects and mechanisms different, eventually leading to the difference of internal force, deformation and damage characteristics. The yielding mechanism of the ceramic compressible layer consists of mutual wedging action, dislocated displacement and squeezing break, while that of the crushed stone compressible layer only contain the first two parts. Due to the particle characteristic, the degree
of ceramic moving to and extruding in area, where ground stress is smaller, is higher than the angular crushed stone under unequal compressive stress. Not only the yielding effects of ceramic is increased, but also the resistance coefficient in that area is enhanced, thus the mechanical properties of segment lining is improved. The research results can provide reference for the future design of support structure type of deep inclined shaft constructed by TBM method.
胡雄玉 何川 杨清浩 曹凇宇 . 管片衬砌配合陶粒可压缩层支护结构型式的模型试验研究[J]. 土木工程学报, 2017, 50(12): 111-121.
Hu Xiongyu He Chuan Yang Qinghao Cao Songyu . Model test of new-type support structure for segment lining combined with compressible ceramic. 土木工程学报, 2017, 50(12): 111-121.