黄土的独立物性指标及其与湿陷性参数的相关性分析  

Correlation analysis of collapsible parameters and independent physical indices of loess

作　　者：邵生俊[1,2] 杨春鸣[1,2] 马秀婷[1,2] 陆斯[1,2] 

机构地区：[1]西安理工大学岩土工程研究所,西安710048 [2]西安理工大学陕西省黄土力学与工程重点实验室,西安710048

出　　处：《岩土力学》2013年第S2期27-34,共8页Rock and Soil Mechanics

基　　金：国家自然科学基金项目(No.41272320)

摘　　要：黄土的湿陷性是其重要的工程特性,常用一维压缩应力条件下的湿陷系数、自重湿陷系数和湿陷起始压力等指标定量评价。影响黄土湿陷性的因素较多,包括土的粒度、密度、湿度等基本物理性质指标,且各因素之间并非完全独立,存在一定相关性。采用因子分析法,通过对西安地铁4号线黄土高台地和宝鸡—兰州高速铁路隧道黄土塬湿陷性黄土场地地层物性质指标的统计分析和相关性分析,首先确定了相对独立的含水比(含水率与液限之比)和孔隙比3个物性指标反映的两个因子。然后,依据湿陷性黄土场地的试验资料,通过多元线性回归分析,分别得到了两个场地黄土的自重湿陷系数、湿陷起始压力以及压缩模量与含水比和孔隙比之间的相关关系。最后,比较分析了两个场地黄土自重湿陷系数、湿陷起始压力和压缩模量计算值与实测值,验证了利用因子分析法寻找影响黄土湿陷性的独立因子,建立黄土湿陷性参数与独立影响因子之间相关关系的合理性和准确性。针对两个地区两类地貌单元湿陷性黄土场地,建立的黄土湿陷性参数的相关关系具有快速、准确的评价黄土湿陷性和黄土地基湿陷变形的实际意义。Collapsibility is an important engineering characteristic of loess, which is indicated by the collapsibility coefficients, dead weight collapsibility coefficients and the initial collapse pressure under the condition of one-dimensional compression stress. There are many influencing factors of collapsible deformation characteristics such as grain size, density and moisture of soil. There is a certain correlation between the influencing factors which are not completely independent. Based on the physical indices statistical analysis and correlation analysis on the collapsible loess fields of loess high platform of Xi'an metro line No.4 and loess tableland of high-speed railway tunnel from Baoji to Lanzhou, the ratio of water content to the liquid limit, and the void ratio are determined to be the factors by the factor analysis method. The multiple linear regression analysis method is used to obtain the relationship between the dead weight collapsibility coefficients, the initial collapse pressure, the modulus of compressibility and the factors according to the test data of two collapsible loess fields. The deviation tests of calculated value and the measured value of the dead weight collapsibility coefficients, the initial collapse pressure and the modulus of compressibility are carried out. The rationality and the accuracy of determining the factors and establishing the relationship between the collapsible parameters and the independent influence factors are verified by the factor analysis method. The valuable significance of the rapid and accurate evaluation of collapsibility and the collapsible deformation of loess foundation is proved by setting up the correlativity of the collapsible parameters of loess in two types of topographic feature of two loess regions.

关 键 词：湿陷性黄土 湿陷变形 物性指标 因子分析法 相关分析 

分 类 号：TU444[建筑科学—岩土工程]