砂介质渗透性影响因素的试验研究  

Experimental study on the influencing factors of permeability of sand media

作　　者：高宗军 丁子祺 刘久潭 刘文悦 GAO Zongjun;DING Ziqi;LIU Jiutan;LIU Wenyue(College of Earth Science and Engineering,Shandong University of Science and Technology,Qingdao,Shandong 266590,China)

机构地区：[1]山东科技大学地球科学与工程学院,山东青岛266590

出　　处：《水文地质工程地质》2024年第6期8-17,共10页Hydrogeology & Engineering Geology

基　　金：国家自然科学基金项目(41641022)。

摘　　要：达西试验是砂介质渗透性能的主要确定方法。但是受到砂介质粒度与压实度、水的溶解性总固体(TDS)与水头差、试验温度等多种因素的影响,获得的达西试验结果存在巨大差异,给实际应用造成很大的不确定性。为探究不同条件下达西试验产生的不同结果,在常温常压环境下,选择不同砂介质,开展不同温度、TDS、供排水水头差等情况下的试验。结果表明:(1)水温增高,渗透系数增大,渗透性越好的介质,受温度的影响越显著;(2)TDS增高,渗透系数减小,渗透性好的介质,渗透性随TDS呈对数函数或指数函数变化,即水在低TDS变化时引起的介质的渗透性变化剧烈,反之亦然,而渗透性差的介质,渗透性随着TDS增高近似呈线性减小;(3)供排水水头差增加到一定值时,渗透系数不再恒定,临界雷诺数细砂为0.4,中砂为3.3;(4)压实度越高,渗透系数越小;(5)孔隙度相同时,粒径越大则渗透系数越大。本试验结果将为今后渗透系数的获取、应用提供借鉴,为地下水评价、地质灾害防治等水文地质参数选取提供依据。The Darcy test is the primary method for determining the permeability of sand media.However,factors such as particle size and compaction of the sand medium,differences between the total dissolved solids(TDS)and the head of the water,and the test temperature,leading to great differences in the results of the Darcy test,cause great uncertainty to the practical application.To explore the variability in Darcy’s test results under different conditions,different sand media were selected under normal temperature and pressure,and tests were carried out considering varying temperatures,TDS,and poor water supply and drainage heads.The results show that the higher the water temperature,the higher the hydraulic conductivity,the better the permeability,and the more significant the influence of temperature.Higher TDS decreases the permeability.In media with high permeability,changes in hydraulic conductivity due to variations in TDS follow a power or exponential function,with low TDS causing drastic changes,while for poorly permeable media,hydraulic conductivity decreases linearly as TDS increases.When the difference between water supply and drainage head reaches a certain value,the hydraulic conductivity is no longer constant,with the limit Reynolds number of 0.4 for fine sand and 3.3 for medium sand.The higher the degree of compaction,the smaller the hydraulic conductivity.when the porosity is the same,the larger the particle size,the greater the hydraulic conductivity.The test findings provide valuable information for the acquisition and application of hydraulic conductivity in the future,and also provide a basis for the selection of hydrogeological parameters such as groundwater evaluation and geological disaster prevention.

关 键 词：达西试验 渗透系数 温度 溶解性总固体 供排水水头差 压实度 砂介质粒度 

分 类 号：P641.2[天文地球—地质矿产勘探]