| 引用本文: | 李镜培,李险峰,张亚国.CPTU确定饱和土体水平渗透系数的改进方法[J].哈尔滨工业大学学报,2016,48(8):185.DOI:10.11918/j.issn.0367-6234.2016.08.031 |
| LI Jingpe,LI Xianfeng,ZHANG Yaguo.A modified approach to determine horizontal permeability coefficient of saturated soils based on CPTU[J].Journal of Harbin Institute of Technology,2016,48(8):185.DOI:10.11918/j.issn.0367-6234.2016.08.031 |
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| 摘要: |
| 目前采用的球面流或半球面流模型所预测的饱和土体渗透系数普遍低于实测值, 为提高孔压静力触探(CPTU)测试技术确定饱和土体水平渗透系数的准确性，针对初始超孔隙水压力的分布形式、孔压过滤环的位置和渗流模型3个主要问题，在回顾前人方法基础上，提出一种基于CPTU确定饱和土体水平渗透系数kh的改进方法.根据已有研究成果，将锥肩附近初始超孔隙水压力视为负指数型衰减分布，结合圆柱面径向渗流模型，推导出饱和土体水平渗透系数的计算公式，应用算例验证了本文方法的合理性，再结合上海某地的实测数据，将本文方法与已有方法进行对比分析，研究结果显示：本文方法计算的渗透系数大于已有方法，更接近室内渗透试验的结果；CPTU测试技术可用于连续且快速地计算饱和土体水平渗透系数.
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| 关键词: 孔压静力触探 饱和土体 改进方法 水平渗透系数 |
| DOI：10.11918/j.issn.0367-6234.2016.08.031 |
| 分类号:TU413 |
| 文献标识码:A |
| 基金项目:国家自然科学基金(41272288) |
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| A modified approach to determine horizontal permeability coefficient of saturated soils based on CPTU |
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LI Jingpe1,2, LI Xianfeng1,2 , ZHANG Yaguo1,2
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(1.Department of Geotechnical Engineering, Tongji University, Shanghai 200092, China; 2.Key Laboratory of Geotechnical and Underground Engineering (Tongji University), Ministry of Education, Shanghai 200092, China)
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| Abstract: |
| To increase accuracy of estimating permeability coefficient of saturated soils using piezocone penetration tests (CPTU), taking account that the permeability coefficient of saturated soils estimated by the existing flow model to the spherical or the hemispherical surface is generally lower than the measured value, a modified approach was proposed, in which the initial excess pore water pressure, the location of filter element and seepage model were studied after the researches on evaluation of permeability coefficient of saturated soils were briefly reviewed. Based on the existing results, the initial excess pore water pressure around the shoulder of the cone was regarded as negative exponential attenuation distribution. Combined with the radial flow model to a cylindrical surface, the expression of horizontal permeability coefficient of saturated soils was derived. The comparison between the predicted and measured values demonstrates that the modified approach is reasonable and effective. The results show that the horizontal permeability coefficient determined by the modified approach is larger than that of previous approaches and more close to the corresponding measured value in laboratory tests. The horizontal permeability coefficient of saturated soils can be continuously and rapidly determined by CPTU.
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| Key words: piezocone penetration test saturated soils modified approach horizontal permeability coefficient |
