基于岩体蠕变试验的Burgers改进模型

Research on improved Burgers model based on rock mass creep test

以湖北潘口水电站进水口边坡岩体为研究对象进行室内蠕变试验,得到岩样的应力-应变曲线和相应的力学参数;对本构模型进行分析,提出改进方法。在Mohr-Coulomb准则(M-C准则)基础上引入新的M-C塑性元件,提出Burgers改进蠕变模型。研究结果表明:白云石英片岩和绿泥钠长片岩具有明显的蠕变特性,在不同级别的荷载力加载下,加载应力与应变以比例方式增大;这2种岩体材料同时具有黏塑、瞬塑、瞬弹和黏弹特性,这4种特性随着应力增大也呈增强趋势;这2种岩体材料在饱和状态下蠕变现象更明显;Burgers改进蠕变模型能够对黏弹塑性偏量特征及弹塑性体积进行模拟。

Taking Hubei Pankou hydropower station intake rock slope as object, creep test in laboratory was made to obtain the stress strain curve of rock mass and the corresponding mechanical parameters. The constitutive model was analyzed and an improvement method was proposed. A new M-C plastic component was introduced and the Burgers improved creep was proposed. The results show that muscovite quartz schist and sodium chlorite schist have obvious creep properties. At different levels of load stress, load stress and strain increase proportionately, and the two kinds of rock mass materials possess the characteristics of viscous-plastic, instantaneous-plastic, instantaneous-elastic and viscous-elastic. The four properties improve with the increase of the stress. The creep phenomenon of the two kinds of rock mass materials is more obvious in saturation condition. The Burgers improved creep can simulate the viscoelastic plastic displacement characteristics and the elastic-plastic volume behavior.