【摘要】：低滲透巖土是水文地質(zhì)及環(huán)境地質(zhì)研究的重點(diǎn)關(guān)注對象,有效擴(kuò)散系數(shù)是研究低滲透巖土的關(guān)鍵參數(shù)之一。文章以原狀黏土和粉砂質(zhì)黏土為例,以Cl~-為示蹤劑,利用自主研發(fā)的室內(nèi)徑向擴(kuò)散實(shí)驗(yàn)裝置,建立Cl~-徑向運(yùn)移模型,模擬其擴(kuò)散運(yùn)移過程。以實(shí)驗(yàn)?zāi)Ｐ蜑槌跏紬l件和邊界條件,利用COMSOL軟件模擬溶質(zhì)理論濃度隨時間變化的曲線,與實(shí)驗(yàn)數(shù)據(jù)進(jìn)行擬合,利用絕對殘差平均值進(jìn)行理論濃度與實(shí)測值擬合優(yōu)度統(tǒng)計(jì),提取試樣的有效擴(kuò)散系數(shù)。結(jié)果表明:試樣塘沽G1孔101.2~101.5 m、蘇北SY1孔147.1~147.3 m、170.48~170.68 m的有效擴(kuò)散系數(shù)分別為6.0×10~(-10)m~2/s、4.5×10~(-10)m~2/s、3.9×10~(-10)m~2/s時,理論濃度的絕對殘差平均值最小,且孔隙度和有效擴(kuò)散系數(shù)高度相關(guān),進(jìn)一步證明了該實(shí)驗(yàn)方法的可行性。同時,利用Archie定律有效孔隙度與有效擴(kuò)散系數(shù)的關(guān)系,取常量n=1.9,預(yù)測了試驗(yàn)樣品的有效孔隙度,分別為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).
【作者單位】： 國土資源部地裂縫地質(zhì)災(zāi)害重點(diǎn)實(shí)驗(yàn)室;中國地質(zhì)大學(xué)(武漢)環(huán)境學(xué)院;中國地質(zhì)大學(xué)(武漢)盆地水文過程與濕地生態(tài)恢復(fù)學(xué)術(shù)創(chuàng)新基地;
【基金】：國土資源部地裂縫地質(zhì)災(zāi)害重點(diǎn)實(shí)驗(yàn)室開放基金(江蘇省地質(zhì)調(diào)查研究院)(EFGD2013007) 國家自然科學(xué)基金(41272258) 湖北省自然科學(xué)基金(KZ15K380) 中國地質(zhì)大學(xué)(武漢)教學(xué)實(shí)驗(yàn)室開放基金資助項(xiàng)目
【分類號】：P641.2;X14
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本文編號：2184089