压实黄土非线性压缩应力-应变关系在地基沉降计算中的应用  

Nonlinear compression stress-strain relationship of compacted loess and its application to calculation of foundation settlement

作　　者：杨晶[1,2] 白晓红[2] 

机构地区：[1]山西大学土木工程系,山西太原030013 [2]太原理工大学建筑与土木工程学院土木工程系,山西太原030024

出　　处：《岩土力学》2015年第4期1002-1008,共7页Rock and Soil Mechanics

基　　金：国家自然科学基金(No.51178287);山西省自然科学基金(No.2010011029)

摘　　要：目前以压缩试验得到的e-p曲线为基础的分层总和法仍然是地基沉降分析中最常用的方法。割线模量法是近年来为人们所熟知的计算地基沉降的新方法,具有不受初始孔隙比影响、便于电算等优点。传统的割线模量法将土体的压缩应力-应变关系视为双曲线形式。通过对压实黄土压缩应力-应变关系曲线的研究和对传统割线模量法计算的割线模量与压缩模量的比较表明,导致割线模量法和e-p曲线法计算结果差异的主要原因是土体压缩应力-应变关系符合双曲线的假定,将压实黄土的应力-应变关系用更符合实际情况的幂函数进行拟合,得到了基于幂函数形式的压缩应力-应变关系曲线的沉降量计算公式,并结合具体工程进行了沉降计算对比分析,将割线模量法进行了推广应用。It is still a common practice to calculate the foundation settlement through the layer-wise summation method using the e-p curve obtained with a compression test. In recent years the secant modulus method（SMM） is increasingly used to calculate the foundation settlement, which is not affected by the initial void ratio of the soil and convenient for computer. The compression stress-strain relationship of soil is expressed as a form of hyperbola in the traditional SMM. The compression stress-strain relationship of loess is discussed and the differences between the secant modulus and compression modulus are analyzed. It is found that the main reason for the discrepancy of calculated results between the SMM and the e-p curve-based method is related to a hyperbolic hypothesis, which assumes that the stress-strain relationship of compacted soils follows hyperbola. To fix the problem, we define the stress-strain relationship of compacted loess using a power function, which can match the actual situation correctly. The settlement formulation using the compression stress-strain relationship with a power function is developed. The proposed method is applied to a practical engineering problem, indicating that the calculated results agree well with measurements.

关 键 词：压实黄土 非线性应力-应变关系 沉降计算 割线模量 双曲线 幂函数 

分 类 号：TU443[建筑科学—岩土工程]