中文摘要：

巷道围岩-支护相互作用体系中围岩承载区是围岩应力的主要承载体,控制围岩承载区域的稳定对巷道围岩的稳定具有积极作用。针对软弱破碎巷道围岩工程地质特性,采用理论分析和数值模拟相结合的方法对巷道围岩承载结构进行研究。考虑巷道开挖后岩体强度、应力和变形特征,建立了软弱破碎围岩巷道的理论计算模型,得到了围岩的应力场、位移场和塑性破坏区范围的解析解;考虑岩石峰后强度软化、剪胀扩容效应、原岩应力和支护阻力等因素的影响,在空间上将巷道围岩承载结构划分为＂浅支撑层＂和＂深支撑层＂,同时在深支撑层内,存在一个高应力区域,承担了围岩的大部分荷载,对深支撑层的承载能力与稳定起着关键作用,称其为＂关键支撑层＂。通过算例分析了围岩残余强度和支护作用对深浅支撑层结构演化特征和巷道变形的影响。采用FLAC3D程序对深浅支撑层结构演化特征及巷道变形进行了数值模拟。研究结果表明：围岩的残余强度越大,深浅支撑层结构在空间上表现的越明显;剪胀扩容效应发生在深支撑层中的软化区内,但其最终导致浅支撑层发生变形;随着原岩应力的增大,巷道围岩深浅支撑层的厚度均不同程度的扩大。

英文摘要：

Surrounding rock plays a key role in the bearing structures of roadway according to the interaction system between surrounding rock and support. Stability control in the bearing structures of surrounding rock thus significantly influence the stability of roadway. Based on the engineering and geological properties of soft and broken surrounding rock,some theoretical models were established considering the strength characteristic,stress distribution and deformation behavior of rock mass after excavation. The stress,displacement and plastic zone were then studied in the elastic zone,plastic soften zone and broken zone,respectively. Considering the influence of several key factors,such as the strength soften and dilation at post-peak state and the support resistance,based on the bearing characteristics of surrounding rock,two main bearing structures around the excavation which are the shallow and deep bearing structureswere defined. A key bearing structure was found in the deep bearing structure,which was subjected to most part of the external load. Theoretical studies and numerical simulation using Flac3 D code were performed to investigate the characteristics of the bearing structures and the deformation of roadway. The results show that the bearing structures will develop obviously with a big residual strength. The dilation effect occurs in the deep bearing structure,while it leads to the deformation of shallow bearing structure. The thicknesses of the two bearing structures increase with the increase of in-situ stress.