采矿与安全工程学报2017，Vol.34Issue(3)：511-518,526,9.DOI:10.13545/j.cnki.jmse.2017.03.016
深部圆形巷道开挖卸荷的围岩力学特征及破坏机理
Mechanical properties and failure mechanism of surrounding rocks in deep circular tunnel under excavation unloading
摘要
Abstract
In view of the strong disturbance induced by unloading excavation of surrounding rocks under high geo-stress,and based on elastic dynamics theory,the approximate analytical solutions of dynamic excavation unloading to the stress were obtained through the application of the residue theorem and the delay characteristic of Laplace transform.The mechanical properties and failure mechanism of deep surrounding rock under unloading condition were studied,based on which a strength criterion and a tension-compression damage model of dynamic excavation unloading were established.The influence of such key factors as in-situ stress,tunnel radius,unloading time,and rock mass dynamical strength on the failure and stability of surrounding rock was investigated through case studies.The results have indicated that under excavation loading,the mechanical behaviors of surrounding rocks in deep tunnel are mainly the minimum principal stress unloading and the maximum principal stress concentrating;the sudden increase of the stress difference induces the propagation and coalescence of cracks in the excavation face,and a continuously distributed fracture zone is developed and a bearing structure is formed to stabilize the supporting rock before secondary support.Under the deep dynamic excavation condition,the damage of surrounding rock tends to be larger with larger geo-stress,bigger tunnel radius,and shorter unloading time;the damage zone in surrounding rocks will be smaller and a better stability of surrounding rocks will be achieved with larger dynamic cohesion and dynamic internal friction angle.The results are important for further study on the failure mechanism of tunnel under a high geo-stress condition.关键词
深部巷道/开挖卸荷/留数定理/延滞性/力学特征/围岩破坏Key words
deep tunnel/excavation unloading/residue theorem/delay characteristic/mechanical properties/failure of surrounding rocks分类
建筑与水利引用本文复制引用
董春亮,赵光明,李英明,孟祥瑞,卢小雨,张立洋..深部圆形巷道开挖卸荷的围岩力学特征及破坏机理[J].采矿与安全工程学报,2017,34(3):511-518,526,9.基金项目
国家自然科学基金项目(51404011,51374013,51574006,51474006) （51404011,51374013,51574006,51474006）
高等学校博士学科点专项科研基金项目(20133415110006) （20133415110006）
霍英东教育基金项目(121050) （121050）
安徽省科技攻关计划项目(160a0802107) （160a0802107）
安徽省自然科学基金项目(1308085ME74) （1308085ME74）
高校优秀拔尖人才培育项目(gxbjZD2016051) （gxbjZD2016051）
安徽高校科研平台创新团队建设项目 （）
安徽省学术和技术带头人及后备人选学术科研活动资助项目 （）
