Abstract Rockburst is one of the main disasters for tunnelling under high ground stress. Taking the rockburst sec? tion of Ping′an Tunnel with high ground stress, which is located on Chengdu-Lanzhou Railway, as the study object,this paper adopts combined methods of filed measurement, numerical analysis, and laboratory test, and with respect to rockburst development mechanism, energy density change and rockburst strength it comprehensively analyzes the impact of two construction schemes (single-tube double-track tunnel system and double-tube single-track tunnel system) on the rockburst in deep-buried extra-long tunnels with high ground stress. The study results show that the order relation of maximum energy density at various locations of the tunnel is Uside wall >Uhance >Utunnel face >Uvault, and rockburst easily occurs at the working face of the tunnel section to be excavated and both side walls of excavated and supported section; compared with vault, hance, side wall and other locations, more energy would be released at the tunnel face, and the stress release holes shall be reasonably installed in the process of excavation; the double-tube single-track tunnel system scheme can effectively reduce the rockburst intensity and the rockburst hazards, so as to better avoid the occurrence of rockburst.
Abstract：
Rockburst is one of the main disasters for tunnelling under high ground stress. Taking the rockburst sec? tion of Ping′an Tunnel with high ground stress, which is located on Chengdu-Lanzhou Railway, as the study object,this paper adopts combined methods of filed measurement, numerical analysis, and laboratory test, and with respect to rockburst development mechanism, energy density change and rockburst strength it comprehensively analyzes the impact of two construction schemes (single-tube double-track tunnel system and double-tube single-track tunnel system) on the rockburst in deep-buried extra-long tunnels with high ground stress. The study results show that the order relation of maximum energy density at various locations of the tunnel is Uside wall >Uhance >Utunnel face >Uvault, and rockburst easily occurs at the working face of the tunnel section to be excavated and both side walls of excavated and supported section; compared with vault, hance, side wall and other locations, more energy would be released at the tunnel face, and the stress release holes shall be reasonably installed in the process of excavation; the double-tube single-track tunnel system scheme can effectively reduce the rockburst intensity and the rockburst hazards, so as to better avoid the occurrence of rockburst.
LUO Chun1 ZHANG Zhiqiang1 LIN Dirui1 TANG Zelin2
.Study of the Impact of Single-and Double-tube Tunnel Systems on Rockburst in Deep-buried Extra-long Tunnelling[J] MODERN TUNNELLING TECHNOLOGY, 2022,V59(2): 28-37
2022, Vol. 59 