复杂应力路径下堆石体本构模型比较验证

目前对堆石体应力-应变关系特性的研究主要建立在常规三轴试验的基础上,对复杂应力路径上堆石体本构模型的验证工作尚不充分.利用糯扎渡高心墙堆石坝主堆石料复杂应力路径大型三轴试验成果,对国内常用的堆石体本构模型——邓肯-张EB模型、清华非线性解耦KG模型和沈珠江双屈服而模型进行了比较和验证.结果表明,邓肯-张EB模型通常会夸大堆石体的体积压缩变形,其加卸载准则无法正确判别一些复杂应力路径的加卸载状况,清华KG模型和沈珠江双屈服面模型对堆石体复杂应力路径的适应性相对较好.

Comparison and verification of constitutive models for rockfill materials under complex stress path

The present studies on stress-strain characteristics of rockfill materials are mainly performed with the conventional triaxial test; and the verification of constitutive model under complex stress path is unsufficient. Using the large scale triaxial test results of Nuozhadu Rockfill materials under complex stress path, the commonly used constitutive models such as Duncan-Chang’s EB model, nonlinear uncoupled Tsinghua KG model and Shen’s double yielding surfaces model are compared and verified. The results show that the Duncan-Chang’s EB model often overestimates the volumetric compression and give incorrect loading-unloading criterion under some complex stress paths. The other two models are more applicable for rockfill materials under complex stress path.