剪胀性饱和砂土弹塑性模型

The dilatancy saturated dense sand elastic-plastic model

在修正剑桥模型基础上,本文建立的剪胀性饱和砂土弹塑性模型使用相变状态参数描述剪胀性饱和砂土剪胀特性,克服了修正剑桥模型不能直接模拟剪胀砂土力学行为这一局限性。该模型有两方面的改进:一方面,模型将剪胀应力比Md引入剪胀方程;另一方面,模型在塑性功基础上提出用与应力路径无关的硬化参数来替代修正剑桥模型中的塑性体积应变增量。通过试验验证及与修正剑桥模型计算结果对比,结果表明,该模型较适合模拟剪胀性饱和砂土的力学性能,同时也能较好地体现较密实砂土的硬化及软化现象。模型共8个参数,用常规三轴试验就可获取。

Based on the modified Cambridge model, the dilatancy saturated dense sand elastic-plastic model in this paper uses the dilatancy parameters and may overcome the shortcomings of the modified Cambridge model which can not directly simulates the dilatancy of the saturated sand. The improvements embody in the following two aspects, firstly, the dilatancy stress ratio Md is introduced into dilatancy equation, and secondly, based on the plastic work, the model presents a hardening parameter independent of stress path and replaces plastic strain increment of the modified Cambridge model. Verified by some test results with the results of the modified Cambridge model, the model is suitable for simulating the characteristics of saturated dilatancy sand, and it also can reflect the hardening and softening characteristics during the shearing process. The model contains 8 parameters that can be obtained directly by the conventional triaxial test.