风沙滩地区煤层采动下潜水位恢复时间影响因素敏感性分析
Sensitivity analysis of factors affecting the phreatic water level recovery time caused by underground coal mining in wind-blown sand area
刘士亮 1张文慧 1王傲 1郑雨生 1王山林 1毛德强 1孙中光2
作者信息
- 1. 山东大学土建与水利学院,山东济南 250100
- 2. 中煤科工集团重庆研究院有限公司,重庆 400039
- 折叠
摘要
西北风沙滩地区煤层采动潜水微渗漏易诱发潜水位发生不同程度的恢复,其恢复时间影响因素敏感性对于矿区生态地质环境保护意义重大.为此,结合井流模型,建立了煤层采后潜水微渗漏下潜水位恢复预计模型;分析了煤层采动下潜水位恢复时间的影响因素;结合正交试验方法,模拟探究了煤层开采及采后恢复过程中潜水渗漏量演化规律,预计了潜水位恢复到采前潜水位埋深的30％,50％,80％所需的时间,并通过极差分析和矩阵分析厘清了潜水位恢复时间影响因素敏感性.结果表明:从地层结构、水文地质和采矿条件等角度确定了潜水位恢复的主要影响因素为基岩厚度Tb、红土厚度Tc、黄土厚度T1、潜水埋深b、含水层厚度Ta、含水层渗透系数K和煤层采厚Tco;潜水发生轻微渗漏的情况下,煤层采后恢复过程中潜水渗漏量整体呈现下降的趋势,采后恢复初期渗漏量下降速度较快,在1～2个月期间下降幅度减少、之后趋于稳定至基本不渗漏;当潜水位恢复到30％时,各因素敏感性次序为:Ta＞K＞Tc＞b＞T1＞Tb＞Tco;当潜水位恢复到50％和80％时,各因素敏感性次序均为:Ta＞K＞b＞T1＞Tc＞Tb＞Tco;影响因素最敏感的两项为T.和K,在水位恢复程度较少的情况下Tc的敏感性相对较大,当水位恢复程度超过50％后b的敏感性则相对较大;Tco和Tb的敏感性相对较小.采前潜水含水层的渗透系数及厚度越大,潜水位恢复所用时间越短.
Abstract
The phreatic micro-leakage caused by underground coal mining is prone to induce va-rying degrees of the phreatic level recovery in the wind-blown sand beach area of northwest,China.The sensitivity of factors affecting the recovery time is of great significance for the eco-geological environment protection of the mining area.Therefore,combined with the well flow model,a prediction model for the recovery time of phreatic water level under phreatic micro-leakage after coal mining was established.The factors influencing the recovery time of phreatic water level were analyzed.By combining the orthogonal experimental method,the evolution law of phreatic leakage during coal seam mining and post mining recovery process was simula-ted,and the time required for the post mining phreatic water level to 30％,50％,80％of the pre-mining phreatic water level buried depth was estimated.Furthermore,the sensitive factors influencing the recovery time of phreatic water level were determined using range analysis and matrix analysis.The results show that the main influencing factors for phreatic water recovery have been determined from the perspectives of stratigraphic structure,hydrogeologic and min-ing condition like bedrock thickness Tb,laterite thickness Tc,loess thickness T1,the buried depth of phreatic water level b,aquifer thickness Ta,aquifer permeability coefficient K,and coal seam mining thickness Tco.Under the condition of phreatic micro-leakage,the overall phreatic water leakage during the post mining recovery process shows a decreasing trend.In the initial stage of post-mining recovery,the leakage rate decreases rapidly,and after one to two months,the decline rate decreases and stabilizes to almost no leakage.When the phreatic water level is restored to 30％of the pre-mining phreatic water level buried depth,the sensitiv-ity order of each factor is Ta＞K＞Tc＞b＞T1＞Tb＞Tco.When the phreatic water level is re-stored to 50％and 80％of the pre-mining phreatic water level buried depth,the sensitivity or-der of each factor is Ta＞K＞b＞T1＞Tc＞Tb＞Tco.The two most sensitive influencing fac-tors are Ta and K,and the sensitivity of Tc is relatively large when the degree of phreatic wa-ter level recovery is less,and the sensitivity of b is relatively large when the degree of phreatic water level recovery exceeds 50％.The sensitivity of Tco and Tb is relatively small.The greater the permeability coefficient and thickness of the pre-mining phreatic water aquifer,the shorter the time required for the recovery of the phreatic water level.
关键词
煤层采动/潜水位恢复时间/影响因素/正交试验/敏感性Key words
orthogonal test/coal seam mining/phreatic water level recovery time/influencing factors/sensitivity引用本文复制引用
基金项目
国家自然科学基金项目(42007239)
济南市2023年科技创新发展计划第十七批(社会民生专项)项目(202317001)
重庆市博士"直通车"项目(CSTB2023NSCQ-BSX0009)
出版年
2024
NETL
NSTL
万方数据