基于现场压水的同一条断层不同位置阻渗差异性研究  

Study on impermeability of different sites for the same fault based on in⁃situ water injection test

作　　者：朱术云[1] 王永军 吕文茂 张民 张强 ZHU Shuyun;WANG Yongjun;LYU Wenmao;ZHANG Min;ZHANG Qiang(Institute of Mine Water Hazards Prevention and Controlling Technology,School of Resources and Geosciences,China University of Mining and Technology,Xuzhou,Jiangsu 221116,China;Department of Geological Survey,Yankuang Energy Group Company Limited,Zoucheng,Shandong 273500,China;Yangcun Coal Mine,Yankuang Energy Group Company Limited,Jining,Shandong 272118,China)

机构地区：[1]中国矿业大学资源与地球科学学院,矿山水害防治技术基础研究实验室,江苏徐州221116 [2]兖矿能源集团股份有限公司地质测量部,山东邹城273500 [3]兖矿能源集团股份有限公司杨村煤矿,山东济宁272118

出　　处：《采矿与安全工程学报》2024年第4期759-768,共10页Journal of Mining & Safety Engineering

基　　金：江苏高校优势学科建设工程项目;国家自然科学基金项目(41741020)。

摘　　要：为研究杨村煤矿十采区内两工作面揭露的同一条断层不同位置预开采煤层底板的断层带阻渗性,在两工作面内选取了A、B测试区域依次进行了针对断层带的原位压水试验。绘制了A测试区域4次,B测试区域3次共7次压水过程中的注水水压、监测水压和流量的历时变化曲线,获得了起始导渗和稳态渗流条件,并对起始导渗和稳态渗流条件下的差异性进行了量化分析。发现与A区域内测试断层带相比,B区域内测试断层带中的原生微裂隙在多次高水压压渗测试后发生了较大的连通反应。在此基础上,基于压水过程中的相关渗透系数公式进行了分析,计算结果表明两断层带的渗透性均弱;但通过对比A、B测试区域获取的渗透系数平均值,发现在A区域内渗透系数在多次重复压渗后升高了2.4倍,B区域内渗透系数在多次重复压渗后升高了20%,揭示了断层作为一种破碎胶结的裂隙岩体在两不同位置处具有明显的各向异性和非均质性。最后通过两位置处压水水压P和流量Q之间散点图所拟合的P⁃Q变化曲线特征,与相关规程及研究对比,认为两位置压水断层带类型属于冲蚀型和扩张型,断层带裂隙不发育,但裂隙中充填有密实程度不同的阻渗充填物,一旦压水水压超过临界值,部分充填物被冲蚀,微裂隙就会发生一定程度的扩展。但因充填程度不同,导致断层带不同位置渗透性发生差异性变化。In order to study the impermeability of the same fault exposed by two working faces in No.10 Mining Area of Yangcun Coal Mine,which is in different sites of the pre⁃mined seam floor fault zones,the in⁃situ water injection tests of fault zone A and B were carried out successively.The chan⁃ging curves of water injection pressure,monitoring water pressure and flow rate in test area A for 4 times and test area B for 3 times were plotted in the process of water injection.The initial permeability and steady seepage characteristics were obtained,the differences of the two sites were analyzed for ini⁃tial permeability and steady seepage conditions.It is found that the fault fracture zone at site B has more larger connectivity reaction than the original micro⁃fracture zone at site A under the action of high pressure seepage tests.On this basis,calculation formula of permeability coefficient was used in the process of water injection tests,the permeability of both site fault zones was very weak.However,by comparing the average permeability coefficient of test site A and site B,the permeability coefficient of in⁃situ test in the area of site A after repeated pressure seepage tests increased nearly 2.4 times,site B permeability increased about only 20%.It shows that the fault,as a kind of fractured rock mass,has obvious anisotropy and heterogeneity in two sites.Through the characteristics of P⁃Q change curve fitted by the scatter plot between the piezometric water pressure P and flow rate Q at the two sites,and comparing with the relevant regulations and studies,the fault zone types should belong to the erosion and expanding types at two sites,respectively.Fault fracture is not developed,but the fractures are filled with impermeable fillings with different degrees of densification,once the water injection pressure exceeds the critical value,the part fillings are eroded,the micro⁃fissures should expand to a certain extent.However,due to the different filling compaction degree,the permeability of different site

关 键 词：现场压水 同一条断层 断层带阻渗差异性 渗透系数 P⁃Q关联特征 

分 类 号：TU45[建筑科学—岩土工程]