土的三维渐近状态准则

Three-dimensional asymptotic state criterion for soils

天然地基中土是在某种约束下而受力变形的,试验结果表明,土在等应变增量比的路径约束下,无论应力路径的起点如何最终都会逼近于应力比为一常数的稳定状态,称为渐近状态。简要分析了渐近状态下土的剪胀规律,应变增量比作为反映剪胀性的一个参数,可以用来描述渐近状态应力比,结合广义非线性强度准则,把土渐近状态应力比的计算推广到三维,提出了土的三维渐近状态准则,并详细分析了该准则中各参数对渐近状态应力比的影响程度,最后通过试验验证了准则的有效性。

The deformation is suffered by shearing when the natural soils are in some strain constraints.The experimental results show that a constant strain increment ratio path in soils will lead to a constant stress ratio for any initial stress state.These states are called the asymptotic ones.The shearing deformation mechanism of the soils in the asymptotic state is analyzed.The stress ratio in the asymptotic state is affected by a volumetric strain increment ratio which controls the dilatancy of the soils.The equation,used to calculate the stress ratio in the asymptotic state,is developed to three-dimensional stress state based on the generalized nonlinear strength criterion.This equation is called the three-dimensional asymptotic state criterion.The comparison between the test results and criterion calculation is analyzed.