颗粒破碎效应对堆石坝应力变形的影响

颗粒破碎对堆石体的变形有重大影响，颗粒破碎除与母岩强度有关外，与应力状态密切相关，高堆石坝堆石体的大部分变形正是高应力场下颗粒破碎的反映。沈珠江院士提出的南水双屈服面模型虽可以较全面地反映堆石体的变形特性，但未充分考虑颗粒破碎引起的剪缩特性，因此坝体变形计算结果往往偏小，适用于中低堆石坝的分析中。本文的计算方法在南水双屈服面模型的基础上，考虑了堆石体在一定应力状态下颗粒破碎引起的应变，较真实地反映了堆石体的变形特性，可为堆石坝尤其是高堆石坝的应力变形研究提供更为合理的结果。

Analysis of particle breakage influence stress-strain behavior of rockfill dams

The particle breakage has a great influence on the deformations of a rockfill body. Apart from the strength of parent rocks, stress state of rockfill is losely related with the particle breakage degree. Most of the deformations of a high rockfill dam is a reflection of particle breakage under high stress state. Although NHRI’s double yield surface model puts forward by Shen Zhu-jiang (member of CAS) well reflects the deformability of rockfill, the model can not adequately reflect the shear shrinkage induced by particle breakage. So the deformation calculated by NHRI’s model is usually smaller than the real one, and therefore NHRI’s model is only applicable to stress-strain analysis for medium and low rockfill dam. Based on NHRI’s double yield surface model, a numerical analysis method considering strain effects induced by particle breakage is presented in this paper. The method can better reflect the deformability of rockfill. So its calculation result is more reasonable for rockfill dams, especially the high rockfill dam.