流固耦合作用下含不同长度裂隙灰岩注浆加固特性试验研究  

Experimental study on grouting reinforcement characteristics of limestone with different length cracks under fluid solid coupling

作　　者：陈军涛[1,2,3] 李昊 贾东秀[4] 马庆 李文昕 CHEN Juntao;LI Hao;JIA Dongxiu;MA Qing;LI Wenxin(College of Energy and Mining Engineering,Shandong University of Science and Technology,Qingdao 266590,China;State Key Laboratory of Coal Mining and Clean Utilization,Beijing 100013,China;National Demonstration Center for Experimental Mining Engineering Education,Shandong University of Science and Technology,Qingdao 266590,China;Qiuji Coal Mine,Shandong Energy Xinwen Mining Group Co.,Ltd.,Dezhou 251105,China;State Key Laboratory of Hydroscience and Engineering,Tsinghua University,Beijing 100084,China)

机构地区：[1]山东科技大学能源与矿业工程学院,山东青岛266590 [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]山东科技大学矿业工程国家级实验教学示范中心,山东青岛266590 [4]山东能源新汶矿业集团有限责任公司邱集煤矿,山东德州251105 [5]清华大学水沙科学与水利水电工程国家重点实验室,北京100084

出　　处：《煤炭科学技术》2024年第3期189-199,共11页Coal Science and Technology

基　　金：国家自然科学基金资助项目(51974172);山东省自然科学基金资助项目(ZR2022ME140);煤炭资源高效开采与洁净利用国家重点实验室资助项目(2021-CMCU-KF015)。

摘　　要：黄河北煤田因矿井水害影响,安全高效开采煤炭资源成为矿井发展的关键瓶颈。注浆技术是当前解决矿井水害问题的重要手段,不仅能解放大量受到水害威胁的煤炭资源,而且对保护地下水资源具有积极意义。对黄河北煤田邱集煤矿取得的灰岩试样开展室试验,观察了灰岩的细观特征,获取了流固耦合作用下含不同长度裂隙灰岩的力学特性及注浆加固特性,通过理论分析得到了灰岩随预制裂隙长度变化时,起裂强度的变化规律,分析了注浆加固机理。结果表明:注浆后岩石的强度、韧性得到明显改善,注浆前的灰岩有明显的脆性特征,注浆后灰岩的脆性降低延性增强;注浆加固体的破坏程度随着裂隙长度的增加越来越剧烈,当裂隙长度较大时伴随有水平方向的裂隙发育;注浆加固体的峰前渗透率的降低程度较小,峰后渗透率有明显的降低,灰岩渗透率最大阶段产生在峰后阶段、而渗透率最小的阶段发生在应力–应变曲线的线弹性阶段,并且裂隙长度越长越容易出现渗透率双峰现象。使用连续介质力学理论推导得到了注浆加固体起裂强度和断裂韧度的计算式,理论证明了注浆加固体的强度大于原岩试样;岩石弹性模量与注浆形成的结合体的弹性模量的差异越大,注浆对岩石强度的影响越弱。It is difficult to fully develop coal resources in the north of the Yellow River due to the influence of mine water disaster.Grouting technology is an important means to solve the problem of mine water disasters at present.The in-depth study of grouting technology can not only liberate a large number of coal resources threatened by water disasters,but also have positive significance for the protection of groundwater resources.Laboratory tests were conducted on limestone samples obtained from Qiuji Coal Mine in the Yellow River North Coalfield to observe the microscopic characteristics of the limestone.The mechanical properties and grouting reinforcement characterist-ics of limestone with different lengths of cracks under fluid solid coupling were obtained.Through theoretical analysis,the variation law of the cracking strength of limestone with the change of prefabricated crack length was obtained,and the grouting reinforcement mechanism was analyzed.The test results show that the strength and toughness of the rock after grouting have been significantly improved,the lime-stone before grouting has obvious brittleness characteristics,and the brittleness of the limestone after grouting has decreased and the ductil-ity has increased;The damage degree of grouting plus solid is more and more severe with the increase of crack length.When the crack length is large,it is accompanied by horizontal fracture development;The pre-peak permeability of grouting plus solid decreases slightly,and the post-peak permeability decreases significantly.The maximum stage of limestone permeability occurs in the post-peak stage,while the minimum stage of permeability occurs in the linear elastic stage of the stress-strain curve.The longer the fracture length,the easier the double-peak phenomenon of permeability appears.Based on the theory of continuous medium mechanics,the formulas for calculating the crack initiation strength and fracture toughness of grouting plus solid are derived.It is theoretically proved that the strength of grouting

关 键 词：注浆加固 裂隙长度 流固耦合 渗透率 起裂强度 

分 类 号：TD745[矿业工程—矿井通风与安全]