Model Test Study on Deformation and Failure of Large-span Flat Tunnel Caused by Additional Load
(1 Shenzhen Transportation Public Facilities Construction Center, Shenzhen 518000；2 Civil Engineering Center of Ministry of Education Information Technology, Tongji University, Shanghai 200092；3 Shanghai Engineering Research Center of Underground Infrastructure Detection and Maintenance Equipment, Shanghai 200092)
Abstract：
Based on the large-span flat Maluanshan tunnel in Shenzhen, the failure process of tunnel structure un?
der the action of additional load in the surrounding rocks of grade Ⅳ and Ⅴ is studied by model test and the change rules of surrounding rock pressure, lining deformation and internal force of tunnel lining are analysed. The research results show that: (1) the surrounding rock pressure at crown increases at first and decreases later, and reaches the maximum with small lining deformation when additional load reaches certain critical value; (2) with an increase of additional load, deformation of lining experiences elastic stage, plastic stage and failure stage, and the lining deformation is large in the surrounding rock of gradeV; (3) with an increase of additional load, internal force of tunnel lining increases and the distributions of bending moment and axial force present the forms of "butterfly" and " rhombus",with more nonuniformity of distribution.
CAI Xin1 LIU Huixi1 CHEN Fubin1 WU Lianbo1 NIU Bingyan2 LIU Xuezeng2,
3 SANG Yunlong2,
3
.Model Test Study on Deformation and Failure of Large-span Flat Tunnel Caused by Additional Load[J] MODERN TUNNELLING TECHNOLOGY, 2020,V57(4): 150-157
2020, Vol. 57 