不同饱和黏性土渗透系数预测方法的应用与对比:以苏北沿海平原黏土为例

发布时间：2018-02-28 23:32

本文关键词： 黏性土渗透系数 δO化学示踪室内实验经验公式苏北沿海平原水文地质　出处：《地球科学》2017年05期 　论文类型：期刊论文

【摘要】：渗透系数(K)是水文地质、岩土工程领域的重要参数,而低渗透介质的结构较为复杂,在实际应用中,场地的尺度、介质的扰动程度等均会对K的确定产生影响.利用δ~(18) O化学示踪法、室内试验及经验公式法估算饱和黏性土的垂向渗透系数,并对比分析不同预测方法的适用性.以苏北沿海平原第四纪厚层黏土为例,δ~(18) O化学示踪法预测厚层黏性土的渗透系数低于10~(-11) m/s,室内法测得渗透系数为2.61×10~(-8)~9×10~(-12) m/s,经验法预测值较大,是室内法的几倍到几十倍.δ~(18) O化学示踪法是表征天然条件下长时间的实验结果,除了反映数十米厚层黏性土的等效渗透性能,还可预测黏土孔隙水的渗流时间;结合测定黏土样品液塑限等室内实验参数,室内实验和经验公式法可以提供系列剖面黏土的渗透系数,更清晰地说明厚层黏土剖面不同渗透系数预测方法的差异性.
[Abstract]:Permeability coefficient K) is an important parameter in the field of hydrogeology and geotechnical engineering, but the structure of low permeability medium is more complicated. The degree of disturbance in the medium has an effect on the determination of K. The vertical permeability coefficient of saturated clay is estimated by means of 未 ~ (18) O chemical tracer method, laboratory test and empirical formula method. The applicability of different prediction methods was compared and analyzed. Taking the Quaternary thick clay in the coastal plain of northern Jiangsu Province as an example, the 未 ~ (18) O chemical tracer method was used to predict the permeability coefficient of thick clay layer less than 10 ~ 10 ~ (-11) m / s, and the permeability coefficient measured by indoor method was 2.61 脳 10 ~ (-8) ~ (-8) 脳 10 ~ (-12) m / s. The 未 ~ (18) O chemical tracer method is the experimental result of long time under natural conditions, which not only reflects the equivalent permeability of tens of meters thick layer clay, but also predicts the percolation time of clay pore water. The laboratory experiment and empirical formula method can provide the permeability coefficient of clay in a series of sections, and more clearly explain the difference of different permeability coefficient prediction methods in thick clay profile.
【作者单位】：国土资源部地裂缝地质灾害重点实验室;中国地质大学环境学院;中国地质大学湿地演化与生态恢复湖北省重点实验室;
【基金】：国家自然科学基金项目(No.41272258) 国土资源部地裂缝地质灾害重点实验室开放基金项目(No.EFGD2013007)
【分类号】：TU43

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