基于Talbot理论的断层破碎凝灰岩三轴渗透特性试验  

Triaxial permeability test of fault fractured tuff based on Talbot theory

作　　者：黄昌富 张帅龙[1,2] 高永涛 吴顺川[2,3] 周喻[2] 孙浩 王文强 王悦 杨文志 HUANG Changfu;ZHANG Shuailong;GAO Yongtao;WU Shunchuan;ZHOU Yu;SUN Hao;WANG Wenqiang;WANG Yue;YANG Wenzhi(China Railway 15th Bureau Group Co.Ltd.,Shanghai 200070,China;School of Civil and Resource Engineering,University of Science and Technology Beijing,Beijing 100083,China;Faculty of Land Resource Engineering,Kunming University of Science and Technology,Kunming 650093,China;School of Energy and Engineering,Henan Polytechnic University,Jiaozuo 454000,China;The First Engineering Co.Ltd.,China Railway 16th Bureau Group,Beijing 101300,China)

机构地区：[1]中铁十五局集团有限公司,上海200070 [2]北京科技大学土木与资源工程学院,北京100083 [3]昆明理工大学国土资源工程学院,云南昆明650093 [4]河南理工大学能源科学与工程学院,河南焦作454000 [5]中铁十六局集团第一工程有限公司,北京101300

出　　处：《中南大学学报（自然科学版）》2022年第8期3092-3103,共12页Journal of Central South University:Science and Technology

基　　金：国家自然科学基金资助项目(52004017);中央高校基本科研业务费专项资金资助项目(FRF-IDRY-20-024)。

摘　　要：为研究富水断层破碎凝灰岩在不同轴向位移、围压及渗透压条件下的渗流特性和渗流失稳基本特征,采用破碎岩石三轴渗流试验系统,开展三轴压缩条件下不同Talbot幂指数n的级配破碎凝灰岩渗流试验,得到破碎凝灰岩渗流特性参数及非线性渗流失稳特征,并研究渗流参数随孔隙率的演化规律。研究结果表明:1)在三轴应力条件下,不同幂指数n的级配破碎凝灰岩的渗透参数更加符合非线性Forchheimer关系,拟合度不低于99%。当幂指数n相同时,渗透率k随孔隙率φ_(0)增大而增大,非Darcy因子β随孔隙率φ_(0)增大而减小。β因子的绝对值反映了非线性渗流特征的强度,β因子为负值时,极有可能发生渗流失稳突变。2)当幂指数n为0.2和0.4时,级配试样在高应力及高水压条件下存在渗流失稳突变现象,利用雷诺数Re判断破碎凝灰岩试样在三轴应力条件下渗流紊乱程度,得到雷诺数的最大值为12.518。3)在三轴应力条件下,渗透率k随幂指数n和孔隙率φ_(0)增大而非线性增大,非Darcy因子β相应呈整体减小趋势。级配粒径越细小或孔隙结构越复杂,破碎凝灰岩渗流过程的非线性特征越明显。随着轴向位移与围压增大,渗透率k的量级为10^(−12)~10^(−13)m^(2),非Darcy流因子的量级为106~19 m^(−1)。In order to study the seepage characteristics and basic characteristics of infiltration and outflow stability of water-rich fault broken tuff with different axial displacements, confining pressures and osmotic pressures, the seepage tests of different Talbot power index n graded broken tuff samples under triaxial compression conditions were carried out using a broken rock triaxial seepage test system. The broken tuff seepage characteristic parameters and nonlinear infiltration and outflow stability characteristics were obtained, and the evolution law of seepage parameters with porosity was studied. The results show the following three facts. 1) Under the condition of triaxial stress, the permeability parameters of fractured tuff with different n-values gradation are more in line with the nonlinear Forchheimer relationship, and the fitting degree is not less than 99%. When the power index n is the same, the permeability k increases with the increase of the porosity φ_(0), and the non-Darcy factor β decreases with the increase of the porosity φ_(0). The absolute value of the β factor can reflect the strength of the nonlinear seepage characteristics. When the β factor is negative, it is very likely that the mutation of infiltration and outflow stability will occur. 2) When the power exponent n is 0.2 or 0.4, there exists the phenomenon of infiltration and outflow stable mutation under high stress and high water pressure conditions. The Re is used to determine the degree of seepage disturbance of the broken tuff sample under the condition of triaxial stress, and the maximum value of Reynolds number is 12.518. 3) Under the condition of triaxial stress, the permeability k increases nonlinearly with the increase of the power exponent n and the porosity φ, and the non-Darcy factor β shows an overall decreasing trend accordingly. The finer the gradation particle size or the more complex the pore structure,the more obvious the nonlinear characteristics of the seepage process of broken tuff. With the increase of axia

关 键 词：断层 破碎凝灰岩(颗粒) 三轴应力 渗流特性 孔隙率 雷诺数 

分 类 号：TU42[建筑科学—岩土工程]