采用劈裂法试验获得了非饱和原状黄土的抗拉强度, 并用滤纸法对劈裂破坏后的黄土试样进行了基质吸力的 测定, 分析了含水率和基质吸力对抗拉强度的影响, 同时探讨了抗拉强度与粘聚力的关系。试验结果表明: 非饱和 原状黄土的抗拉强度很小, 抗拉强度随含水率的增大而减小, 基本为负的指数函数关系; 抗拉强度随基质吸力的增 大而增大, 两者之间呈幂函数关系; 当土体含水率小于缩限时, 抗拉强度的增大幅度远远小于基质吸力; 抗拉强度随 粘聚力的增大而增大, 两者之间为良好的线性关系, 此种线性关系应是土体的固有性质。

The tensile strength o f unsaturated natural lo ess w as determined by the splitt ing method. The matric suctio n of loess sample aft er fractur ing w as measured using the filt er paper method. T he effects o f water co ntent and matric suction on the ten2 sile st rength w ere ana lyzed and the relatio nship betw een the tensile str eng th and cohesion was discussed. The results show ed the tensile strength of unsatur ated natural lo ess is ver y small and it decreases w ith the increasing o f w ater content in a neg ativ e ex2 ponent ial function; t he tensile str eng th incr eases w ith the increasing o f matric suction in a pow er functio n; the incr easing rate of tensile streng th is f ar less than that o f mat ric suctio n when w ater content is less than shrinkage limit of so il sample; and the ten2 sile strength increases with the incr easing of cohesion in a g ood linear relationship, and this r elationship is t he int rinsic charac2 ter istic of natural lo ess.

陕西省科技统筹创新工程计划项目( 2012KTDZD03203)