土木工程与力学学院知识库

本文在系统分析大厚度自重湿陷性黄土地基湿陷及渗透特性国内外研究现状的基础上，在我国关中、豫西、青海等地选择多处典型湿陷性黄土场地，通过大规模现场试坑浸水试验、室内试验、理论分析和数值模拟相结合的手段，对大厚度湿陷性黄土浸水后的湿陷变形特性、湿陷性黄土下限评价方法以及大厚度黄土地基水分入渗和消散规律进行了系统研究。取得的主要创新性成果有： （1）基于大量现场试坑浸水试验，获得了浸水后大厚度黄土地基自重湿陷变形的时域衍生特征及三维发展规律。 （2）建立了自重湿陷性黄土下限现场试坑浸水试验实测值和相应的室内试验值之间的定量关系；分析了二者差异的形成机理；首次提出了现场试验中湿陷性黄土下限的确定方法以及对室内试验结果的修正方法。 （3）提出了大厚度黄土湿陷性综合评价方法。 （4）揭示了水在大厚度原状黄土地基中的入渗规律、浸水影响范围，得到了大厚度黄土地基竖向和水平向不同部位的渗透系数及其变化规律，分析了水分渗透与湿陷变形的关系，为定量评价黄土湿陷性以及工程防排水设计提供了直接依据。 （5）建立了可用于估算大厚度黄土地基剩余含水率的经验公式，填补了该领域的研究空白。

In this thesis, based on literature study on domestic and international study on collapse and seepage, through pit flooding test, laboratory test, theoretical analysis and numerical simulation, the collapse, depth limit assessment of collapse, pore water seepage and dissipation of sites respectively in central Shaanxi, west Henan and Qinghai are studied. The new findings obtained with this study are as follows: (1) The time-domain and 3D collapse deformation development under pit flooding was systematically studied. (2) The comparison of collapse depth limit of self-weight collapse of loess respectively by field tests and laboratory tests found that generally and site-independently the results obtained from the two kinds of tests are objectively different. For the first time, a modification method was proposed to modify the collapse depth limit got from the laboratory loess test (3) A comprehensive evaluation method of collapsible loess with large thickness is put forward. (4) The patter and range of seepage were revealed quantitatively, both horizontal and vertical permeability coefficient were measured to provide reference for loess seepage damage control and drainage design. (5) An empirical formula was established to assess the residual water cut of large depth loess ground, which fills the blank in this study field.