基于位错理论的饱和土渗流特性CPTU评价研究

发布时间：2018-05-06 23:10

本文选题：孔压静力触探 + 孔压　；参考：《岩土工程学报》2014年03期

【摘要】：孔压静力触探(CPTU)测试数据通常用于土层划分和岩土工程设计参数评价。国际上CPTU测试技术的最新进展之一在于采用测得的锥尖阻力、侧壁摩阻力和孔隙水压力快速、连续地获得饱和土的渗透系数,以避免孔压消散试验费时的缺点。首先简要回顾了基于CPTU测试资料确定饱和土渗透系数的的研究成果,并进行了分析与改进,提出了基于位错理论和圆柱面径向流模型的水平向渗透系数预测新方法。选取典型场地进行了CPTU测试,并在黏性土场地采用薄壁取土器获得无扰动的原状试样,进行室内水平向渗透试验,在无黏性土场地进行现场钻孔抽水试验。以室内渗透试验和现场抽水试验的结果为参考,对3种基于CPTU连续评价饱和土渗透系数的方法进行了对比分析。研究表明,位错理论适用于评价饱和土的原位渗透系数,然而准确性与所采用的渗流模型有关。对国际标准CPTU探头,孔压过滤环位于锥肩(u2)位置时,采用圆柱面的径向流模型能够获得最为准确的水平向渗透系数预测结果,采用球面流或半球面流模型时趋于低估土层的渗透性。
[Abstract]:The test data of pore pressure static penetration (CPTU) is usually used for soil layer division and evaluation of geotechnical engineering design parameters. One of the latest developments of international CPTU testing technology is to use the measured cone tip resistance, side wall friction resistance and pore water pressure fast, to continuously obtain the permeability coefficient of saturated soil, in order to avoid the time-consuming shortcomings of the pore pressure dissipation test. Firstly, the research results of determining the permeability coefficient of saturated soil based on CPTU test data are briefly reviewed, and the analysis and improvement are carried out. A new method based on dislocation theory and radial flow model of cylindrical surface is proposed. A typical site is selected for CPTU test, and a thin-walled soil collector is obtained in the clay soil site. The undisturbed original specimen was tested in the indoor horizontal penetration test, and the field drilling test was carried out in the cohesionless soil site. Based on the results of indoor penetration test and spot pumping test, the analysis of 3 methods based on CPTU continuous evaluation of saturated soil permeability coefficient was analyzed. The study shows that the dislocation theory is suitable for evaluation of saturation. The accuracy of the in-situ permeability coefficient of soil is related to the seepage model adopted. For the international standard CPTU probe, when the pore pressure filter ring is located in the cone (U2) position, the radial flow model of the cylindrical surface can obtain the most accurate prediction results of the horizontal permeability coefficient, and the surface layer is underestimated when the spherical or hemispherical flow model is used. Permeability.

【作者单位】：东南大学岩土工程研究所;
【基金】：国家自然科学基金项目(41202203,41330641) 国家科技支撑计划项目(2012BAJ01B02) 教育部新世纪优秀人才支持计划(NCET-13-0118) 全国优秀博士学位论文作者专项资金项目(201353) 中央高校基本科研业务费资助项目(2242013R30014)
【分类号】：TU413

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