NUMERICAL SIMULATION OF THE SIZE EFFECT IN CIRCULAR TUNNEL ROCKBURST
Rockburst processes of two circular tunnels with different diameters are modelled by use of FLAC. Rock exhibits linear strain-softening behavior beyond the occurrence of failure, which is followed by ideal plastic behavior. A composite Mohr-Coulomb criterion with tension cut-off is used. Rectangular elements with the same size are adopted. The model is firstly loaded until a static equilibrium state is reached. Then, the excavation is modelling by using a written FISH function. Results show that, when the tunnel with small diameter is excavated, the surrounding rock with four V-shaped notches is still stable after rockbursts. However, when a large-diameter tunnel is excavated, the entire section of the tunnel will collapse and the surrounding rock will lose its stability since many shear bands occur and the maximum unbalanced force is always larger than a limit value.
XUE-BIN WANG YI-SHAN PAN XIAO-LIN WU
College of Mechanics and Engineering, Liaoning Technical University Fuxin, 123000, P.R.China Rockburst Research College, Liaoning Technical University Fuxin, 123000, P.R.China Institute of Computational Mechanics, Liaoning Technical University Fuxin, 123000, P.R.China
国际会议
The 7th International Symposium on Rockburst and Seismicity in Mines(2009年第七届国际岩爆与微振动性学术研讨会)
大连
英文
137-142
2009-08-21（万方平台首次上网日期，不代表论文的发表时间）