温变条件下石灰岩裂隙渗透特性实验研究  

Experiment study on permeability of limestone fracture under temperature variation

作　　者：盛金昌[1] 张肖肖[1] 贾春兰[1,2] 杜昀宸 周庆[1] 詹美礼[1] 罗玉龙[1] 何淑媛[1] 

机构地区：[1]河海大学水利水电学院,江苏南京210098 [2]新疆博衍水利水电环境科技有限公司,新疆乌鲁木齐830000

出　　处：《岩石力学与工程学报》2017年第8期1832-1840,共9页Chinese Journal of Rock Mechanics and Engineering

基　　金：国家自然科学基金资助项目(51579078;51474204;51679070)~~

摘　　要：在中等温度(25℃~90℃)和渗透压的条件下,裂隙渗透性对矿物质的溶解表现的很敏感。因此重点通过4个温度平台阶段(25℃,50℃,70℃,90℃),以温变对流量和等效水力开度的调节过程来反映温度对石灰岩裂隙渗透特性演化规律的影响。测量反应过程中岩样的渗透流量和渗出液的离子浓度,并将测量的渗流量经过经典的立方定律变换得到裂隙开度随时间的变化情况。实验结果表明:升温过程中流量和等效水力开度表现出明显增大的趋势,恒温过程中等效水力开度逐渐变小并趋于稳定;在不变的有效应力下,经历渗透压增大后,随着温度的升高,裂隙开度总体呈下降趋势。通过分析渗流量、等效水力开度和矿物离子浓度随时间变化的过程,以及它们之间的内部关系,得出温度升高能促进应力作用和渗流作用,渗流通道的局部溶解作用也随着温度的变化而改变,从而影响压力溶解和自由溶解的进程。Permeability of fracture is sensitive to the dissolution of minerals under the medium temperatures（25 ℃ - 90 ℃） and osmotic pressures. The flow-through experiments were therefore conducted on the limestone containing a single fracture under 4 different temperatures, 25 ℃, 50 ℃, 70 ;C and 90℃ respectively. The seepage discharge and hydraulic equivalent width of aperture affected by the temperature variation was studied to investigated the permeability characteristics of limestone fracture. During the reaction process, the seepage discharge and the ionic concentration of percolate were measured. The seepage discharge was transformed through the cubic law to obtain the variation of fracture width with time. The experimental results show that the seepage discharge and the hydraulic equivalent width of aperture in the process of temperature rising increase significantly with the time. The hydraulic equivalent width of aperture in the process of constant temperature decreases gradually and finally reaches a stable value. After the increase of osmotic pressure, the width of aperture under the constant effective stress decreases as the increase of temperature. It was found that raising temperature promoted the effect of stress and seepage, and the partial dissolution of seepage channel also changed with the variation of temperature, thus influenced the process of pressure dissolution and free dissolution.

关 键 词：岩石力学 石灰岩裂隙 渗透特性 温度改变 渗流应力耦合 

分 类 号：TU45[建筑科学—岩土工程]