考虑颗粒破碎的堆石体本构模型

Constitutive model for rockfill material considering grain crushing

对于高堆石坝而言,在高应力场作用下堆石颗粒将明显破碎,从而导致坝体变形率增加,因此,在高坝数值计算中必须考虑颗粒破碎的影响。传统的堆石体本构模型由于不能合理反映颗粒破碎的影响,导致计算变形与实测变形差别较大。在基于岩土破损力学二元介质模型概念的基础上,将堆石体视为结构体和破损带组成的二元介质,建立了颗粒破碎率和破损参数之间的关系,提出了可以考虑颗粒破碎的堆石体本构模型。并通过一个大型三轴剪切试验的算例,说明了该模型的合理性。

For high rockfill dams, the grain crushing in high stress field may raise the deformation rate of dam body and should be considered in numerical calculation. Because the traditional constitutive model for rockfill material can not reasonably reflect the effect of grain crushing, the calculated deformation of dam body is much different from the measured one. Based on the concept of binary medium model proposed by Professor Shen Zhujiang, a constitutive model of rockfill material considering grain crushing which was conceptualized as binary medium model consisting of structural system and breaking bond was presented, and the relationship between grain crushing rate and breaking parameter was established. An example of large scale triaxiai test was taken to prove the rationality of the present model.