Abstract In view of the initial support structure of the horseshoe tunnel, the bearing capacity and deformation per? formance of the steel arch and shotcrete initial support structure are analyzed by using full-scale tests and monitoring the internal force, structural surface strain and deformation of the structure by embedding sensors. The results show that: (1) In the elastic phase, the bending moment and axial force on each section of the support structure are symmetrical about the neutral axis of the structure, and the corresponding radial displacement amplitude is small.(2) In the plastic phase, with the increase of the applied load, the bending moment and axial force of the support structure increase rapidly. The support structure presents a deformation state of "convex arch bottom and concave arch waist", and is approximately symmetrical about the neutral axis. (3) The support structure finally failed at the right arch shoulder section steel connection. The concrete and section steel at the failure location were in a large range of peeling state, and the exposed section steel bulge was bent and damaged. The ultimate bearing capacity of the structure was about 1.32 times of the design load.
Abstract：
In view of the initial support structure of the horseshoe tunnel, the bearing capacity and deformation per? formance of the steel arch and shotcrete initial support structure are analyzed by using full-scale tests and monitoring the internal force, structural surface strain and deformation of the structure by embedding sensors. The results show that: (1) In the elastic phase, the bending moment and axial force on each section of the support structure are symmetrical about the neutral axis of the structure, and the corresponding radial displacement amplitude is small.(2) In the plastic phase, with the increase of the applied load, the bending moment and axial force of the support structure increase rapidly. The support structure presents a deformation state of "convex arch bottom and concave arch waist", and is approximately symmetrical about the neutral axis. (3) The support structure finally failed at the right arch shoulder section steel connection. The concrete and section steel at the failure location were in a large range of peeling state, and the exposed section steel bulge was bent and damaged. The ultimate bearing capacity of the structure was about 1.32 times of the design load.
WANG Yawei ZHAO Xiuwang ZHU Yi GUO Jianglong
.Full-scale Experimental Study on Mechanical and Deformation Properties of Initial Support Structure of Horseshoe Tunnel[J] MODERN TUNNELLING TECHNOLOGY, 2023,V60(1): 186-194
2023, Vol. 60 