钙质结核含量对黄土强度及变形特性的影响

Effect of Calcium Tuberculosis Content on Strength and Deformation Characteristics of Loess

通过室内直剪试验研究不同钙质结核含量对试样的强度、变形等特性的影响。研究发现,钙质结核对试样的抗剪强度指标影响很大,随着钙质结核含量增多,试样的粘聚力降低,内摩擦角增加。在高正应力下试样中的钙质结核的骨架作用能够充分发挥,含量越高强度越大。低正应力下,含钙质结核试样的剪切变形曲线是应变软化型,而不含钙质结核试样的应力-应变曲线为应变硬化型。随着钙质结核含量、正应力的增加,在理想塑性阶段曲线明显不同。

Through the indoor direct shear test,the influence of different calcareous tuberculosis content on the strength and deformation characteristics of the sample was tested,which provides theoretical guidance for engineering construction.It was found through experiments that calcareous tuberculosis has a great influence on the shear strength index of the sample.As the calcium tuberculosis content increases,the cohesive force of the sample decreases and the internal friction angle increases.The skeleton effect of calcareous nodules in the sample under high normal stress can be fully exerted,and the higher the content is,the greater the strength will be.Under low normal stress,the calcium-containing tuberculosis samples are strain-softened,while the calcium-free tuberculosis samples are strain-hardened.With the increase of calcareous tuberculosis content and normal stress,the curves in the ideal plasticity stage are significantly different.