华北水利水电大学学报（自然科学版）2024，Vol.45Issue(6)：97-108,12.DOI:10.19760/j.ncwu.zk.2024071
基于自然电位的裂隙-基质系统溶质运移试验研究
Experimental Study of Solute Transport in Fracture-matrix System Based on Self-potential
摘要
Abstract
In order to finely delineate the process and characteristics of solute transport in the rock fractures,a sandbox(0.20 m×0.03 m×0.50 m,L×W×H)was made by plexiglass plates.There is a fracture in the center of the sandbox,and on both sides of the fracture is the matrix.The fracture and matrix in the sandbox form a fracture-matrix system.The solute transport experiments were carried out under different grain size matrix seepage velocities by self-potential,a nondestructive and fast monitoring means,to study the solute transport characteristics of the fissure-matrix system.The results are as fol-lows.①In the range of test flow rate 0.009 7～3.195 9 mm/s,the fracture permeability coefficient in the system is 5.5×10-2 m/s,and the difference between matrix permeability coefficient 2.4×10-3 m/s and 3.5×10-4 m/s steps is not signifi-cant,the flow conforms to Darcy's law.And with the continuous reduction of matrix particle size,the water flow changes from Darcy flow to non-Darcy flow when the difference between fracture permeability coefficient 5.5×10-2 m/s and matrix permeability coefficient 3.6×10-5 m/s is about 3 orders of magnitude.②Follow the solute transport direction under three different matrix conditions with different particle sizes,the peak SP of the fracture domain and matrix domain electrode measurement points decreased continuously and the peak arrival time increased one by one with the decreasing matrix per-meability coefficient.③With the increasing flow rate,the peak SP time of the slit domain and matrix domain electrode points appeared earlier and the peak SP time of the slit domain electrode measurement points at the same system flow rate was shorter compared with the matrix domain.④Flow velocity can be quantified by SP peak time and solute transport dis-tance.The calculated flow velocity value is slightly smaller than the measured flow velocity value of the system,and the correlation fitting coefficient R2 is greater than 0.99,among which the error coefficient calculated by using the self-potential value of the measurement point of the fracture domain electrode is controlled within 10%,which is higher than the calcula-tion accuracy of the flow rate in the matrix domain,which is highly consistent with the experimental phenomenon and pro-vides a reference for exploring the solute transport process in the fracture-system.关键词
自然电位/溶质运移/裂隙-基质系统/非达西流Key words
self-potential/solute transport/fracture-matrix system/non-Darcy flow分类
天文与地球科学引用本文复制引用
王展,闫亚景,赵贵章,丁力,刘少康,李文曦..基于自然电位的裂隙-基质系统溶质运移试验研究[J].华北水利水电大学学报（自然科学版）,2024,45(6):97-108,12.基金项目
国家自然科学基金面上项目(41372260) （41372260）
南京水利科学研究院水文水资源与水利工程科学国家重点实验室"一带一路"水与可持续发展科技基金资助项目(2021490511) （2021490511）
华北水利水电大学研究生教育创新计划基金项目(YK-2021-68). （YK-2021-68）
