破碎岩体锚固及承载失稳机制研究  

Study on reinforcement and bearing-instability mechanism of broken rock mass

作　　者：李建忠 高富强[1,2,3] 娄金福 原贵阳[1,2,3] LI Jianzhong;GAO Fuqiang;LOU Jinfu;YUAN Guiyang(CCTEG Coal Mining Research Institute,Beijing 100013,China;State Key Laboratory of Coal Mining and Clean Utilization,Beijing100013,China;Coal Mining Branch,China Coal Research Institute,Beijing 100013,China)

机构地区：[1]中煤科工开采研究院有限公司,北京100013 [2]煤炭资源高效开采与洁净利用国家重点实验室,北京100013 [3]煤炭科学研究总院开采研究分院,北京100013

出　　处：《采矿与安全工程学报》2022年第6期1125-1134,共10页Journal of Mining & Safety Engineering

基　　金：天地科技股份有限公司开采设计事业部科技创新项目(KJ-2019-TDKCSYS-01);国家自然科学基金项目(52074154)。

摘　　要：破碎岩体锚杆支护加固作用已被普遍证明,但对荷载作用下破碎岩体锚固及承载失稳机制仍不清晰。基于此,开展系列破碎岩体锚固试验,揭示破碎岩体锚固及承载失稳机制,得出不同条件下破碎岩体稳定承载支护条件,提出破碎岩体锚固支护建议。与常规岩体锚杆支护受力特征截然相反的是,破碎岩体在荷载作用下产生变形破坏特征响应时,锚杆受力呈现逐渐衰减演化特征,锚杆支护对破碎岩体支护作用仅体现为施加预紧力产生的主动支护效应。锚固破碎岩体间呈力链结构铰接,以压力拱结构承载,拱下岩体起着支撑压力拱及将锚杆支护作用传递至压力拱的力学媒介作用,是压力拱能否稳定承载的关键。破碎岩体产生变形破坏响应特征时,岩体间力链结构稳定性降低,拱下岩体对压力拱支撑及将锚杆支护作用传递至压力拱的力学媒介作用减弱。破碎岩体锚固失稳机制表现为拱下岩体支撑作用弱化及锚杆支护作用衰减双重因素叠加诱导的结构性失稳。不同物理力学及支护参数条件,改变的是压力拱拱下岩体稳定性及其力学媒介作用,影响破碎岩体压力拱结构稳定性及锚杆支护作用。获得了不同物理力学参数条件下破碎岩体锚固稳定承载条件,提出了破碎岩体锚固支护合理建议:统计破碎岩体平均粒径,确定合理锚杆支护密度;提高锚杆预紧力及护表支护强度。The effect of bolting support of broken rock mass has been generally proved,however,the mechanism of bearing-instability and bolt support remains unclear. A series of broken rock mass support physical model tests were carried out. The bearing-instability and support mechanism of broken rock mass is revealed,and stable bearing support conditions of broken rock mass is obtained. Suggestions for broken rock mass support are proposed. In contrast to the bolt force characteristics of traditional rock mass,when broken rock mass has deformation and failure characterizes,the force of bolt will gradually decay and evolve. The supporting effect of the bolt on the broken rock mass is only reflected in the active supporting effect produced by the application of the pre-tension force. Under the action of bolt support,the broken rock masses are hinged in a force-chain structure and carried by the pressure arch. Rock masses under the pressure arch support the pressure arch and transfer the support to the pressure arch,which is the key to the stability of the pressure arch. When the broken rock mass deforms to be failure,the structure of the force-chain is weakened,and the supporting effect and mechanical medium that transfers the bolt force to the pressure arch of the rock mass under the arch is reduced. The instability mechanism of broken rock mass is the structural instability induced by the weakening of supporting effect of the rock mass under the arch and the attenuation of the supporting effect. Under the conditions of different physical mechanics and support parameters,what changes is the stability of the rock mass under the pressure arch and its mechanical medium effect,which affects the stability of the pressure arch and active support of bolt. The stable bearing conditions of broken rock mass under different physical and mechanical parameters were revealed,and reasonable suggestions for broken rock mass support were proposed to:analysis average particle size of broken rock mass,determine reasonable bolt density,and inc

关 键 词：破碎岩体 锚杆支护 压力拱 失稳机制 力学媒介 

分 类 号：TD322[矿业工程—矿井建设]