Creep analysis of high concrete-faced rockfill dam

摘要

The focus of the present study of a concrete-faced rockfill dam (CFRD) is the time-dependent deformation problem of rockfill, especially under a high confining pressure. In this paper, a new creep constitutive model for rockfill is introduced. A numerical realization step and algorithm applied to the analysis using the general finite element method is also presented for the creep model. The numerical simulation result of the creep model is compared with data from a laboratory triaxial creep test. It is concluded that the creep model can describe the real creep characteristics and mechanical behavior of rockfill. In studying the stress and deformation behavior of the high rockfill dam, and considering the creep effect, the creep model is applied in performing creep analysis of the Shuibuya CFRD with 200 m high in China, now the highest constructed CFRD in the world. In comparing the creep numerical simulation results with those of previous analyses that did not consider the creep effect, the deformation of the dam exhibits an evident increment, and the rockfill creep has an obvious influence on the deformation and stress of the concrete-face slab. The prediction of the final maximum settlement was 2.09 m for the Shuibuya Dam, with the rockfill creep effect in accord with the creep parameters of the triaxial creep test.