非饱和黄土的结构性与强度特性的关系  

Relationship between structure and strength property of unsaturated loess

作　　者：张宁宁[1] 骆亚生[1] 

机构地区：[1]西北农林科技大学水利与建筑工程学院,陕西杨凌712100

出　　处：《中南大学学报（自然科学版）》2015年第5期1838-1844,共7页Journal of Central South University:Science and Technology

基　　金：国家自然科学基金资助项目(51178392)~~

摘　　要：根据原状黄土、重塑黄土和饱和重塑黄土的应力-应变曲线对比,定义黄土结构强度势参数η。通过三轴试验探讨不同围压和含水率对土体结构强度势参数的影响,研究土体结构强度势参数与其抗剪强度指标之间的关系。研究结果表明:围压和含水率是影响土体结构性的2个主要因素,结构强度势参数随不同围压的变化曲线均处在一较狭窄的条带范围内,具有很好的归一性,结构强度势参数随含水率的增大而减小;土体结构强度势参数随着轴向应变的增长先线性增长在达到峰值后又呈指数形式迅速衰减;结构强度势参数与黏聚力具有指数关系,结构强度势参数与内摩擦角具有线性关系;考虑结构强度势参数的抗剪强度准则可以全面地反映具有结构性土体的强度特性,比莫尔-库仑强度准则更符合实际工程。Based on the stress-strain curves of undisturbed loess, disturbed loess and saturated disturbed loess, structural parameter η was defined. The effect of confining pressure and moisture content on structural parameter was analyzed, and the relationship between structural strength potential parameter and shearing strength parameter was discussed. The results indicate that the structure of loess is mainly affected by confining pressure and moisture content. The relationship curves between structural strength potential parameter and confining pressure have the very good normalization in a relatively narrow band range. The water content of loess is larger, and its structure parameter＇ peak is stronger. The structure parameter increases linearly, then reaches the peak, and later decreases exponentially with the increment of strain. The relationship between structural strength potential parameter and cohesion is exponential and the structural strength potential parameter is linearly related to internal friction angle. The shear strength criterion, which considers structural strength potential parameter, comprehensively specifies strength property of structural soil, and it is superior to Mohr-Coulomb strength criterion, and more in line with actual engineering.

关 键 词：非饱和黄土 结构强度势参数 抗剪强度 围压 含水率 

分 类 号：TU444[建筑科学—岩土工程]