低渗透岩土有效扩散系数的室内测定与分析
发布时间：2018-08-15 11:40
【摘要】：低渗透岩土是水文地质及环境地质研究的重点关注对象,有效扩散系数是研究低渗透岩土的关键参数之一。文章以原状黏土和粉砂质黏土为例,以Cl~-为示踪剂,利用自主研发的室内径向扩散实验装置,建立Cl~-径向运移模型,模拟其扩散运移过程。以实验模型为初始条件和边界条件,利用COMSOL软件模拟溶质理论浓度随时间变化的曲线,与实验数据进行拟合,利用绝对残差平均值进行理论浓度与实测值拟合优度统计,提取试样的有效扩散系数。结果表明:试样塘沽G1孔101.2~101.5 m、苏北SY1孔147.1~147.3 m、170.48~170.68 m的有效扩散系数分别为6.0×10~(-10)m~2/s、4.5×10~(-10)m~2/s、3.9×10~(-10)m~2/s时,理论浓度的绝对残差平均值最小,且孔隙度和有效扩散系数高度相关,进一步证明了该实验方法的可行性。同时,利用Archie定律有效孔隙度与有效扩散系数的关系,取常量n=1.9,预测了试验样品的有效孔隙度,分别为0.26,0.19,0.16。
[Abstract]:Low permeability rock and soil are the focus of hydrogeology and environmental geology research, and effective diffusion coefficient is one of the key parameters to study low permeability rock and soil. Taking the undisturbed clay and silty clay as examples, using Cln- as tracer, an indoor radial diffusion model is established to simulate the diffusion migration process. Taking the experimental model as the initial condition and the boundary condition, the curve of solute theoretical concentration varying with time is simulated by COMSOL software, which is fitted to the experimental data, and the absolute residual average value is used to calculate the goodness of fit between the theoretical concentration and the measured value. Effective diffusion coefficient of extracted sample. The results show that the effective diffusivity of sample is 6.0 脳 10 ~ (-10) m ~ (-10) m ~ (-2) / s ~ (4.5 脳 10 ~ (-10) ~ (-10) ~ (-10) ~ (-10) ~ (-10) mm ~ (-10) ~ (-10) mm ~ (-10) ~ (-1) m ~ (-1) ~ (-10) ~ (-10) mm ~ (-10) ~ (-10) ~ (-10) m ~ (-1) ~ (-10) ~ (-10) mm ~ (-10) ~ (-10)? The feasibility of the experimental method is further proved. At the same time, by using the relationship between effective porosity and effective diffusion coefficient of Archie's law, the effective porosity of test samples is predicted, which is 0.26 ~ (0.19) ~ (0.16).
【作者单位】： 国土资源部地裂缝地质灾害重点实验室;中国地质大学(武汉)环境学院;中国地质大学(武汉)盆地水文过程与湿地生态恢复学术创新基地;
【基金】：国土资源部地裂缝地质灾害重点实验室开放基金(江苏省地质调查研究院)(EFGD2013007) 国家自然科学基金(41272258) 湖北省自然科学基金(KZ15K380) 中国地质大学(武汉)教学实验室开放基金资助项目
【分类号】：P641.2;X14
，
本文编号：2184089
[Abstract]:Low permeability rock and soil are the focus of hydrogeology and environmental geology research, and effective diffusion coefficient is one of the key parameters to study low permeability rock and soil. Taking the undisturbed clay and silty clay as examples, using Cln- as tracer, an indoor radial diffusion model is established to simulate the diffusion migration process. Taking the experimental model as the initial condition and the boundary condition, the curve of solute theoretical concentration varying with time is simulated by COMSOL software, which is fitted to the experimental data, and the absolute residual average value is used to calculate the goodness of fit between the theoretical concentration and the measured value. Effective diffusion coefficient of extracted sample. The results show that the effective diffusivity of sample is 6.0 脳 10 ~ (-10) m ~ (-10) m ~ (-2) / s ~ (4.5 脳 10 ~ (-10) ~ (-10) ~ (-10) ~ (-10) ~ (-10) mm ~ (-10) ~ (-10) mm ~ (-10) ~ (-1) m ~ (-1) ~ (-10) ~ (-10) mm ~ (-10) ~ (-10) ~ (-10) m ~ (-1) ~ (-10) ~ (-10) mm ~ (-10) ~ (-10)? The feasibility of the experimental method is further proved. At the same time, by using the relationship between effective porosity and effective diffusion coefficient of Archie's law, the effective porosity of test samples is predicted, which is 0.26 ~ (0.19) ~ (0.16).
【作者单位】： 国土资源部地裂缝地质灾害重点实验室;中国地质大学(武汉)环境学院;中国地质大学(武汉)盆地水文过程与湿地生态恢复学术创新基地;
【基金】：国土资源部地裂缝地质灾害重点实验室开放基金(江苏省地质调查研究院)(EFGD2013007) 国家自然科学基金(41272258) 湖北省自然科学基金(KZ15K380) 中国地质大学(武汉)教学实验室开放基金资助项目
【分类号】：P641.2;X14
，
本文编号：2184089
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