深井巷道“双壳”支护壳体结构力学分析

发布时间：2018-03-31 06:24

本文选题：深井巷道　切入点：蠕变　出处：《河北工程大学》2015年硕士论文

【摘要】：巷道支护是矿井建设的首要工程，巷道围岩稳定受到地应力环境、支护结构、支护强度、断面类型等多重因素影响。深部巷道围岩显现出变形量大、变形速率快、变形持续时间长、变形影响空间大、受采动影响敏感等变形破坏特征，在深部高岩应力作用下巷道围岩显现出明显工程软岩特性，深井软岩巷道治理是巷道支护的难题。本文在国家自然科学基金“深井巷道‘双壳’注浆加固支护机理研究（51174070）”研究基础上，结合工程实际发现巷道围岩变形失稳主要是围岩结构的失稳，支护结构的稳定是巷道支护的重点和关键。基于深井软岩巷道变形破坏特征，结合支护结构稳定性力学分析，，提出了连续“双壳”治理深井软岩巷道围岩稳定的方法。针对深井高应力软岩巷道支护问题，采用现场实测、调研、理论分析、物理实验模拟、实验室试验和数值模拟等多种综合研究方法，对连续“双壳”形成的支护壳——让压壳耦合支护机理与技术进行了系统的研究，得到主要结论如下：（1）物理实验发现巷道围岩应力在变形发展过程中逐渐向深部转移，浅部围岩应力释放，中深部围岩成为应力主承载体；通过数值模拟对比分析圆形巷道与直墙半圆拱形巷道随埋深的变化，围岩应力、位移与塑性区发展规律，总结得出圆形巷道大幅降低深部巷道围岩移近量，减小围岩塑性破坏程度，降低围岩集中压力影响区域，有利于控制深井巷道围岩稳定，对巷道底臌治理尤为显著。（2）为研究巷道围岩蠕变变形规律，进行了岩石单轴及三轴蠕变试验，揭示了垂压、围压对岩石变形量及稳定性的作用；岩石强度极限后单轴及三轴蠕变试验说明了巷道围岩及时支护的意思，以及提高支护强度的原理。（3）基于改善巷道围岩力学性质、降低围岩支撑压力、转变围岩受力状态，提出了连续“双壳”支护理念，巷道围岩浅部注浆+预应力锚杆支护形成浅部支护壳，深部注浆+预应力锚索形成深部加固壳。浅部壳改善岩体力学性能，增大围岩内聚力和内摩察角，提高围岩强度和刚度，改变浅部围岩结构；深部注浆浆液充填胶结岩体裂隙，深部注浆体与锚索共同形成具有一定厚度的闭合环形壳体。（4）提出支护壳——加固壳耦合支护理论，分析了“双壳”耦合支护机理，提出了“合理选择巷道断面，维护巷道围岩结构，一次让压、二次抗压支护”的支护理念和“卸压让压，抗压阻压，卸让适度，让抗协调”的支护原则。
[Abstract]:Roadway support is the most important project in mine construction. The stability of roadway surrounding rock is affected by many factors, such as ground stress environment, support structure, support strength, section type and so on. The deformation duration is long, the deformation influence space is large, the deformation is sensitive to mining, and so on. Under the action of deep high rock stress, the surrounding rock of roadway shows obvious soft rock characteristics. The treatment of soft rock roadway in deep well is a difficult problem in roadway support. This paper is based on the National Natural Science Foundation of China "study on the mechanism of 'double shell' grouting reinforcement support in deep well roadway (51174070)". Combined with engineering practice, it is found that the deformation instability of roadway surrounding rock is mainly the instability of surrounding rock structure, and the stability of supporting structure is the key point and key of roadway support. Based on the deformation and failure characteristics of roadway in deep and soft rock, the mechanical analysis of stability of supporting structure is combined. This paper puts forward a method of controlling the surrounding rock stability of soft rock roadway in deep well by continuous "double shell". In view of the support problem of soft rock roadway with high stress in deep well, field measurement, investigation, theoretical analysis and physical experiment simulation are adopted. In this paper, the mechanism and technology of continuous "double shell" supporting shell coupled with pressure shell are studied systematically by laboratory test and numerical simulation. The main conclusions are as follows:. 1) physical experiments show that the stress of surrounding rock of roadway is gradually transferred to the deep in the course of deformation development, the stress of shallow surrounding rock is released, and the middle and deep surrounding rock becomes the main bearing body of stress; By numerical simulation, the variation of surrounding rock stress, displacement and plastic zone in circular roadway and semi-circular arch roadway with vertical wall are compared and analyzed, and the conclusion is drawn that circular roadway greatly reduces the surrounding rock displacement of deep roadway. Reducing the degree of plastic failure of surrounding rock and decreasing the area affected by concentrated pressure of surrounding rock will help to control the stability of surrounding rock in deep roadway, especially to control the heave of roadway floor. (2) in order to study the creep deformation law of roadway surrounding rock, uniaxial and triaxial creep tests of rock are carried out, and the effects of vertical pressure and confining pressure on rock deformation and stability are revealed. Uniaxial and triaxial creep tests after rock strength limit show the meaning of timely support of surrounding rock and the principle of improving support strength. On the basis of improving mechanical properties of surrounding rock of roadway, reducing supporting pressure of surrounding rock and changing stress state of surrounding rock, the concept of continuous "double shell" support is put forward, and shallow supporting shell of surrounding rock is formed by pre-stressed anchor bolt support in surrounding rock of roadway. Deep grouting prestressed Anchorage cable forms deep reinforcement shell. Shallow shell improves mechanical properties of rock mass, increases cohesion and angle of inner inspection, improves strength and stiffness of surrounding rock, changes shallow surrounding rock structure. The deep grouting body and the anchor cable form a closed annular shell with a certain thickness. (4) put forward the theory of coupling support between support shell and strengthened shell, analyze the mechanism of "double shell" coupling support, put forward the support idea of "reasonable selection of roadway cross section, maintenance of surrounding rock structure of roadway, primary release pressure, secondary compression support" and "release pressure concession pressure". Resistance to pressure, release moderate, let the principle of coordination of support.
【学位授予单位】：河北工程大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TD353

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