高地应力环境下隧道围岩强度特征研究-《高速铁路技术》

文章信息/Info

Title:: Study on the Strength Characteristics of Tunnel Surrounding Rock under High Geo-stress Conditions

Author(s):: YU Hongzhang; FENG Jun; JIANG Bo; ZHANG Guangze; 1. China Railway Eryuan Engineering Group Co., Ltd., Chengdu 610031, China;
2. Northeastern University, Shenyang 110004, China

Keywords:: high geo-stress|surrounding rock strength|large deformation of soft rock|thousand-layer bottom|concept of prevention and control

摘要:: 本文结合铁路隧道工程实例，考虑高地应力地质环境及地质构造特征，将隧道围岩强度进行分类，通过对构造应力为主的软岩大变形形成机理进行分析，提出对该类大变形的防控理念，得出了以下研究结论：（1）高地应力环境下，隧道围岩应考虑三种岩石强度，分别是天然强度、原岩强度和卸荷强度，对以构造应力为主的隧道围岩大变形和岩爆，应着重考虑围岩的卸荷强度；（2）对构造应力为主的软岩大变形，提出"千层底"加固圈的防控理念，并提出"快挖、快支、快锚、快封闭"的主动防控设计方法。

Abstract:: Combined with engineering projects of railway tunnels, the strength of surrounding rock is classified according to the characteristics of geological structure and geological environment under high geo-stress in this paper. Through the analysis of the formation mechanism of large deformation of soft rock mainly caused by the tectonic stress, the concept of prevention and control of this kind of large deformation is put forward. The following conclusions are obtained:(1) 3 kinds of rock strength shall be considered for the tunnel surrounding rock under high geo-stress conditions, which are natural strength, original strength of rock and unloading strength. Unloading strength of surrounding rock shall be considered in particular for the large deformation and rock burst of tunnel surrounding rock mainly caused by the tectonic stress. (2) For large deformation of soft rock caused by tectonic stress, the prevention and control concept of "thousand-layer bottom" reinforcement ring is proposed, and the active prevention and control design method of "fast excavation", fast support, fast anchoring and fast closure is put forward.