围岩在不同开挖步下载荷释放率研究

隧道开挖过程中存在应力释放问题,所以正确模拟围岩荷载释放率是数值分析的关键.以往研究者模拟围岩释放率采用经验法或者二维模拟分析,而隧道开挖是空间问题.因而对于复杂应力状态条件下的隧道开挖会造成很大的误差.因此,本文根据围岩参数三维数值模拟隧道全断面开挖确定荷载释放率.与部分以往研究结果不同,拱底出现隆起,释放率出现负值.

Research into Load Release Rate of Surrounding Rock in Different Tunnel Excavations

Correct simulation of surrounding rock load release rate is a key to numerical analysis due to the existence of stress release in the course of tunnel excavation.Empirical method or two-dimensional simulation analysis is employed to simulate surrounding release rate in the previous research despite the fact that tunnel excavation is a matter of space.Consequently,serious errors are more likely to arise from tunnel excavation under complex stress.As a result,this paper aims to determine the accurate load release rate based on three-dimensional numerical simulations of full-face tunnel excavation.Different from the previous results,this study shows that the tunnel bottom heaves and the release rate is negative.