堆石料的劣化变形和本构模型

Degrading deformation of rockfill materials and its constitutive model

利用新研制的大型堆石料风化试验仪,对一典型泥质粉砂岩堆石料进行了荷载作用下干湿和温度耦合变化的风化试验。研究了在湿冷–干热耦合循环作用下堆石料颗粒的劣化机理,分析了劣化过程所产生的堆石料变形的规律。试验结果表明:湿冷–干热循环可使堆石料试样发生显著的劣化变形,堆石料在自然环境中的劣化变形应是高堆石坝后期变形的重要组成部分。根据试验结果,建立了可以描述堆石料劣化变形的4参数模型,可采用初应变法进行有限元计算。

Laboratory weathering tests on a loaded argillaceous siltstone rockfiU are performed by use of a newly developed test apparatus. The degrading mechanism of rockfill particles and the degrading strain of rockfill materials under the coupled wetting-cooling and drying-heating cycles are investigated. The test results show that the coupled wetting-cooling and drying-heating cycles can induce a remarkable degrading strain for rockfill materials, therefore the degrading strain of rockfill materials owing to variation of natural environment conditions should be a main source of long-term deformation of a high rockfill dam. Based on the test results, a constitutive model for rockfill degrading with four parameters is established, which can be applied to the finite element analysis by the initial strain method.