废弃矿井抽水蓄能巷道衬砌混凝土孔渗特性研究  

Pore penetration characteristics of lining concrete for pumped storage roadways in abandoned mines

作　　者：汪林志 高明中[3] 蔡武[1,2] 张汝佩 马祥 WANG Linzhi;GAO Mingzhong;CAI Wu;ZHANG Rupei;MA Xiang(State Key Laboratory for Fine Exploration and Intelligent Development of Coal Resources,China University of Mining and Technology,Xuzhou,Jiangsu 221116,China;School of Mines,China University of Mining and Technology,Xuzhou,Jiangsu 221l16,China;School of Mining Engineering,Anhui University of Technology,Huainan,Anhui 236025,China)

机构地区：[1]中国矿业大学煤炭精细勘探与智能开发全国重点实验室,江苏徐州221116 [2]中国矿业大学矿业工程学院,江苏徐州221116 [3]安徽理工大学矿业工程学院,安徽淮南236025

出　　处：《中国矿业大学学报》2024年第6期1185-1197,共13页Journal of China University of Mining & Technology

基　　金：国家自然科学基金项目(52374101,32111530138);江苏省研究生科研与实践创新计划项目(KYCX24_2857);中国矿业大学未来科学家计划项目(2024WLKXJ023)。

摘　　要：为了研究废弃矿井抽水蓄能中巷道表面衬砌混凝土孔渗特性的变化规律,基于废弃矿井抽水蓄能工况下巷道所经历的地应力、水头和储放水过程,分析了混凝土在水压渗透下毛细孔的液桥面形状,构建了混凝土水压渗透过程的理论模型.通过改良岩石流变扰动效应仪和自制水泵、硅胶板等,实现了混凝土试样在持压荷载作用下,水压渗透-干燥的干湿交替过程.探讨了混凝土不同荷载水平、渗透水压和干湿交替条件下吸水特性变化,并采用渗透测试仪和核磁共振系统分析渗透率和孔隙结构的变化规律.结果表明:水压渗透过程中混凝土的后期吸水率大于初始吸水率,其中后期吸水率与荷载水平呈正相关,与干湿交替次数呈负相关.干湿交替3次后混凝土的渗透率随荷载水平和水压呈正相关,而在干湿交替7次后渗透率随荷载水平和水压的增加整体上呈减小趋势.混凝土孔隙结构随着干湿交替次数增加经历“基体剥蚀—压缩破坏—基体二次剥蚀”的循环过程,其中水压对该循环过程有促进作用.To investigate the variation patterns of pore seepage characteristics in roadway lining concrete designed for abandoned mine pumped storage,an analysis was conducted on the shape of liquid bridges in the capillary pores of concrete under hydraulic pressure,based on the geostress,hydraulic head,and water storage/release conditions experienced by the roadways in abandoned mine pumped storage scenarios.A theoretical model for the hydraulic seepage process in concrete was developed.The wet-dry alternation process under sustained loading conditions was simulated for concrete samples subjected to hydraulic seepage and drying cycles,utilizing an improved rock rheological disturbance apparatus,a custom-designed water pump,and silicone plates.Changes in water absorption characteristics of concrete under different load levels,hydraulic pressures,and wet-dry alternation conditions were explored,with resulting variations in permeability and pore structure analyzed using a permeameter and NMR.The results indicate that during the hydraulic seepage process,the later water absorption rate of concrete exceeds the initial absorption rate,with a positive correlation to load levels and a negative correlation to the number of wet-dry cycles.After three wet-dry cycles,the permeability of concrete increases in response to higher load levels and hydraulic pressures,however,after seven wet-dry cycles,an overall decline in permeability is observed as load levels and hydraulic pressures increase.Additionally,the pore structure of the concrete undergoes a cyclical process of“matrix erosion—compression damage—secondary matrix erosion”with the increase in the number of wet-dry cycles,where hydraulic pressure plays a promoting role in this process.

关 键 词：废弃矿井 抽水蓄能 持压荷载 干湿交替 水压渗透 

分 类 号：TD353[矿业工程—矿井建设]