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.