深部圆形巷道开挖卸荷的围岩力学特征及破坏机理

发布时间：2018-03-14 17:51

本文选题：深部巷道　切入点：开挖卸荷　出处：《采矿与安全工程学报》2017年03期 　论文类型：期刊论文

【摘要】：针对深部高地应力条件下巷道开挖卸荷造成的围岩强烈扰动问题,基于弹性卸荷理论,运用留数定理和拉氏逆变换的延滞性给出动态开挖卸荷应力解析解。在此基础上,研究深部开挖卸荷下围岩力学特征和破坏机理,根据围岩力学特征建立动态卸荷的强度准则和拉压损伤模型。通过算例探讨初始地应力、开挖半径、卸荷时间和岩体动态强度对围岩卸荷破坏与稳定的影响。结果表明:深部开挖卸荷下围岩力学特征主要表现为最小主应力卸荷、最大主应力集中,而主应力差的瞬间增大,诱发开挖面内裂隙扩展、贯通,形成由强及弱连续分布的破坏区,构成二次支护前维系围岩稳定的支撑结构。深部动态开挖卸荷下,初始地应力和开挖半径越大、卸荷时间越短,围岩损伤越严重,破坏范围越广,对围岩的扰动越强烈;而岩体动黏聚力和动摩擦角越大,围岩的破坏范围越小,围岩越稳定。分析结果对深入研究高地应下巷道开挖的破坏机制具有重要意义。
[Abstract]:For the deep roadway under high ground excavation unloading caused by strong disturbance problems, based on the theory of elastic unloading, using the residue theorem and the inverse Laplace transform of the delay of the dynamic excavation unloading stress analytical solution. On this basis, the research of deep excavation unloading rock mechanics characteristics and failure mechanism. According to the mechanical characteristics of surrounding rock dynamic unloading bearing strength criterion and damage model of tension and compression. The examples of initial stress, the radius of excavation and unloading time and rock dynamic strength of rock unloading failure and stability. The results showed that the unloading rock mechanics characteristics under load is mainly the minimum principal stress unloading in deep the excavation, the maximum principal stress concentration and stress difference increase moment, excavation induced in-plane crack formation, through the continuous distribution of failure zone by the strong and weak, composed of two branches to maintain the stability of the surrounding rock support before the supporting structure. Deep structure. The dynamic unloading of initial stress, the greater the radius of excavation and unloading, the shorter the time, the more serious damage of surrounding rock, damage range more widely, the more intense the disturbance to surrounding rock and rock mass; dynamic cohesion and friction angle is large, the smaller the damage range of surrounding rock, the surrounding rock is more stable. The analysis results of in-depth study of the failure mechanism of tunnel excavation under high geostress is of great significance.

【作者单位】：安徽理工大学煤矿安全高效开采省部共建教育重点实验室;安徽理工大学能源与安全学院;安徽理工大学理学院;兖煤菏泽能化有限公司赵楼煤矿;
【基金】：国家自然科学基金项目(51404011,51374013,51574006,51474006) 高等学校博士学科点专项科研基金项目(20133415110006) 霍英东教育基金项目(121050) 安徽省科技攻关计划项目(160a0802107) 安徽省自然科学基金项目(1308085ME74) 高校优秀拔尖人才培育项目(gxbj ZD2016051) 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
【分类号】：TD322

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