摘要
为解决深部破碎围岩巷道支护困难的问题,以卡斯特纳及基尔斯等理论为基础,着重考虑支护阻力对破碎围岩巷道应力分布规律的影响,建立非静水压力下圆形巷道围岩应力力学模型,并推导出围岩破碎区、塑性区的应力及影响范围的解析解,对比分析两者的不同侧压力系数与支护阻力的变化特征。针对不同区域内围岩破碎程度不同,提出先分层后整体支护、“锚网(索)+底板锚索+喷射混凝土+全断面注浆”修复方案。研究结果表明:巷道开挖后,围岩出现以纵向破坏为主的破坏形式,围岩破碎区和塑性区的环向应力均大于径向应力,且在破碎区、塑性区及弹性区的交界处均出现应力不连续现象;随着侧压力系数不断增大,破碎区与塑性区的半径随之增大,与塑性区半径的增长率相比,破碎区的半径增长率明显较大,围岩越来越趋于破碎;随着支护阻力增大,塑性区和破碎区的半径随之减小,但当支护阻力的强度达到一定强度后,破碎区和塑性区影响范围明显减小,说明支护阻力初期能够起到维持巷道稳定的作用,但一味地增加支护强度,只能增加支护成本,对围岩大变形控制效果十分有限;提出巷道支护向稳定控制转变,而不是强调变形控制;采用修复方案后,顶底板位移以及两帮位移都可以得到明显控制,说明该方案能够长期维持巷道围岩稳定,保证巷道安全使用。
In order to solve the problem of support difficulty in deep broken surrounding rock roadway,based on the theories of Kastner and Kirsch,and the influence of support resistance on stress distribution law of broken surrounding rock roadway,the stress mechanics model of rounded surrounding rock roadway under non-hydrostatic pressure was established.And the analytical solution of stress and influence range in broken zone and plastic zone of surrounding rock was deduced,and then the variation characteristics of different measured pressure coefficients and support resistance were analyzed.According to the degree of breakage in different regions,the solution of layered support followed by integral supporting was proposed,i.e.,"bolt-mesh-anchor+anchor line in baseplate+sprayed concrete+slip casting in full cross-section".The results show that the destructional form of surrounding rock is mainly longitudinal destruction after roadway excavation,and the circumferential stress of the broken and plastic zones in surrounding rock is greater than the radial stress.Besides,the stress discontinuity occurs at the junction of broken zone,plastic zone and elastic zone.With the measured pressure coefficient increases,the radius of the broken zone and the plastic zone increases.Compared with the growth rate of the plastic zone radius,the growth rate of the broken zone radius is obviously larger,and the surrounding rock tends to be broken more and more.With the increase of the support resistance,the radius of the broken zone and the plastic zone decreases.But when the strength of the support resistance reaches a certain value,the influence range of the broken zone and the plastic zone decreases obviously,which indicates that support resistance can play a role in maintaining the stability of the roadway at the initial stage,but merely increasing the support strength can only increase the support cost,and the control effect on the larger deformation of surrounding rock is very limited,and therefore,it is proposed that roadway support sh
作者
彭文庆
朱豪
汪琦
PENG Wenqing;ZHU Hao;WANG Qi(School of Resources Environment and Safety Engineering,Hunan University of Science and Technology,Xiangtan 411201,China)
出处
《中南大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2023年第6期2447-2458,共12页
Journal of Central South University:Science and Technology
基金
国家自然科学基金资助项目(51974118)
湖南省教育厅重点项目(22A0337)。
关键词
应力分布
弹塑性力学
塑性区
破碎区
stress distribution
elastoplastic mechanics
plastic zone
fracture zone
