基于能量耗散修正的Boom clay上下加载面模型及其数值实施

发布时间：2018-09-11 13:44

【摘要】：针对剑桥模型不适用于超固结土和结构性土的局限性,引入上下加载面模型以描述Boom clay的结构性;基于Boom clay的屈服面的特点,通过修改能量耗散函数对上下加载面的形状进行了修正,构造一个更好地反映其特性的弹塑性模型;以有限元程序ABAQUS的UMAT子程序接口为平台,采用隐式积分算法——最近点映射法(closest point projection method,CPPM)实现了模型的二次开发;最后利用该模型对不同围压下的Boom clay不排水三轴试验进行了模拟,并将该模型的计算结果与修正剑桥模型的计算结果以及试验实测结果进行比较,结果表明,该模型能较好地反映Boom clay在剪切过程中的结构性演化,且在一定程度上纠正了常规上下加载面模型高估重超固结土峰值强度而低估正常固结土和轻超固结土峰值强度的问题。
[Abstract]:In view of the limitation that Cambridge model is not suitable for overconsolidated soil and structural soil, the upper and lower loading surface model is introduced to describe the structure of Boom clay, and based on the characteristics of Boom clay yield surface, By modifying the energy dissipation function, the shape of the upper and lower loading surfaces is modified to construct an elastic-plastic model which better reflects its characteristics. The UMAT subroutine interface of the finite element program ABAQUS is used as the platform. The implicit integral algorithm-nearest point mapping method (closest point projection method,CPPM) is used to realize the secondary development of the model. Finally, the undrained triaxial test of Boom clay under different confining pressures is simulated by the model. The calculated results of the model are compared with those of the modified Cambridge model and the experimental results. The results show that the model can well reflect the structural evolution of Boom clay in the shear process. To some extent, the problem of overestimating the peak strength of heavy overconsolidated soil and underestimating the peak strength of normal and light overconsolidated soils is corrected by the conventional upper and lower loading surface models.
【作者单位】：中国科学院武汉岩土力学研究所岩土力学与工程国家重点实验室;山东大学岩土与结构工程研究中心;中煤科工集团西安研究院有限公司;Euridice SCK.CEN比利时核研究中心;
【基金】：国家杰出青年基金资助项目(51225902) 国家自然科学基金资助项目(51109207)
【分类号】：TU43

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