Collapse analysis of tunnel floor in karst area based on Hoek-Brown rock media  

作　　者：YANG Xiao-li LI Zheng-wei LIU Zheng-an XIAO Hai-bo 杨小礼;李正伟;刘拯安;肖海波

机构地区：[1]School of Civil Engineering, Central South University, Changsha 410075, China

出　　处：《Journal of Central South University》2017年第4期957-966,共10页中南大学学报（英文版）

基　　金：Project(2013CB036004)supported by the National Basic Research Program of China;Project(51378510)supported by the National Natural Science Foundation of China

摘　　要：Collapse shape of tunnel floor in Hoek-Brown rock media is investigated with the functional catastrophe theory. The stability of rock system in tunnel floor, which is determined by thickness, half collapse width, half length of cave and detaching curve, has great secure and economic significance in practical engineering. To investigate the failure mechanisms and the outline of detaching block, a reliable damage model is presumed by making reference to the limit analysis theory. The analytical solutions of detaching curve, half collapse width on tunnel floor and the critical and maximum values of collapse thickness are derived based on Hoek-Brown criterion and functional catastrophe theory. The result shows that 0.5 is a most probable condition for instability, and the shape of detaching curve is a part of parabola. It is reasonable by comparing with previous theory and analogous experiments. The effects of major factors on thickness and half collapse width are further discussed. Numerical calculations and parametric analysis are carried out to illustrate the effects of different parameters on the mechanism, which is significant to the stability analysis of tunnel floor in rock media.Collapse shape of tunnel floor in Hoek-Brown rock media is investigated with the functional catastrophe theory. The stability of rock system in tunnel floor, which is determined by thickness, half collapse width, half length of cave and detaching curve, has great secure and economic significance in practical engineering. To investigate the failure mechanisms and the outline of detaching block, a reliable damage model is presumed by making reference to the limit analysis theory. The analytical solutions of detaching curve, half collapse width on tunnel floor and the critical and maximum values of collapse thickness are derived based on Hoek-Brown criterion and functional catastrophe theory. The result shows that 0.5 is a most probable condition for instability, and the shape of detaching curve is a part of parabola. It is reasonable by comparing with previous theory and analogous experiments. The effects of major factors on thickness and half collapse width are further discussed. Numerical calculations and parametric analysis are carried out to illustrate the effects of different parameters on the mechanism, which is significant to the stability analysis of tunnel floor in rock media.

关 键 词：KARST functional CATASTROPHE theory HOEK-BROWN criterion safety thickness TUNNEL FLOOR upper BOUND 

分 类 号：U458[建筑科学—桥梁与隧道工程]