三剪统一屈服准则在柱形孔扩张问题中的应用

Application of the Triple-shear Unified Yield Criterion in the Expansion of Cylindrical Cavity

基于三剪统一屈服准则,通过用3条折线来描述土体的本构特征,对柱形孔扩张问题进行分析,考虑岩土材料的软化和剪胀特性,推导出柱形孔扩张问题下的应力场、应变场、扩张压力、塑性区半径的解析解。算例表明,临界扩孔压力随土的软化程度的减小而增大,在一定剪胀和软化程度下,临界扩孔压力随b的增大而增大。

A unified analytical solution to the stress fields,stain fields,expansion pressure and radius of the plastic is given by considering the strain-softening and shear dilatation characteristics of geotechnical material,basing on the triple-shear unified yield theory and the constitutive relation with the three-line of the soils.The calculation shows that the critical expansion pressure increases with the decreasing of softening.In a certain degree of shear dilation and softening,the critical expansion pressure increases with the increase of b.