摘要:
基于国家对西部煤炭绿色开发的号召,西部矿区煤炭资源开发与生态环境及水资源保护协调发展研究显得愈发重要。煤矿地下水库技术创新性地实现了西部矿区绿色发展,但依然存在着诸多需要克服的科学难题。为了研究煤矿地下水库底板在应力-渗流耦合条件下的渗流规律与破坏特征,分析渗流演变过程中的多场信息,研制了底板渗流模拟试验系统。该试验系统主要包括伺服稳压控制系统、试验箱系统和计算机监测与数据采集系统,其中伺服稳压控制系统可以实现利用气体压力替代水压力模拟地下水库中水体压力和上覆岩层产生的矿山压力,实现了对整体压力(范围为0~0.8 MPa)数字化控制;试验箱系统为钢架结构,可实现模拟不同水位高度下的流固耦合模拟试验,最大模型尺寸为1000 mm×600 mm×500 mm(长×宽×高)。并以神东矿区某煤矿地下水库为背景,进行底板渗流相似模拟试验,获得了孔隙水压力和渗水量变化规律,验证了设备的合理性和实用性。试验结果表明:孔隙水压力和渗流量数据信息可以宏观表征岩层渗流情况;孔隙水压力变化一般需要经历初始维持阶段、增大阶段、峰值波动阶段、衰减阶段和稳定阶段,最大增幅约为0.8 kPa,稳定阶段后孔隙水压力与初始值相差约为0.1 kPa;同一层位不同位置测点和不同层位相同位置测点的孔隙水压力变化曲线趋势基本一致,影响孔隙水压力主要因素有测点位置、模拟岩层岩性、渗透率和材料非均质性等。渗流量大小受过流断面面积和渗透系数影响,最大渗流量范围为14 mL/s~15 mL/s。
Abstract:
Based on the requirements of the green development for the western coal mining area in China,the coordinated development of coal resources development,ecological environment and water resources protection in western mining areas is becoming more and more important.Coal mine underground reservoir technology inno-vatively enhances the green development of western coalfield,however,there are still many scientific challenges to overcome.In order to study the seepage law,the deformation and failure characteristics of underground reservoir floor under the stress-seepage coupling condition,and to analyze the multi-field information in the seepage channel evolution process,a seepage simulation test system of underground reservoir floor was developed independently.The test system mainly consists of a servo stabilized voltage control system,a test chamber system and a computer monitoring and data acquisition system.Among them,the servo stabilized voltage control system can use gas pressure instead of water pressure to simulate the pressure generated by the waterbody of underground reservoir and the pressure generated by overlying strata.It realizes the digital control of overall pressure,and the range of that is 0-0.8 MPa.Test chamber system can realize the simulation test of fluid-solid coupling at different water levels,which is a steel frame structure.The maximum model size is 1 000 mm×600 mm×500 mm (length × width × height).Taking the geological condition of Shendong mining area as the background,the similarity simulation test of floor seepage was carried out.The variation laws of pore water pressure and water leakage were obtained.Also the rationality and practicability of the equipment were verified.The results showed that the pore water pressure and water leakage could characterize the rock seepage macroscopically.Pore water pressure generally needed to go through the initial maintenance stage,the increase stage,the maximum stable stage,the decrease stage and the stable stage.The maximum increase was about 0.8 kPa,and the difference of pore water pressure between the initial value and the stable value was about 0.1 kPa.The trend of pore water pressure variation curve of measuring points at different positions in the same layer and at the same position in different layers was basically similar.The main factors that influenced the pore water pressure include the measuring point,rock lithology,permeability and the heterogeneity of the laying model.The water leakage was influenced by the size of the flow section and permeability coefficient,and the maximum water leakage ranged from 14 to 15 mL/s.