堆石料等应力比路径三模量增量非线性模型

已有研究表明,土石坝内堆石料在填筑期的应力路径可近似为等应力比的路径。根据等应力比三轴排水剪切试验,介绍了一个三模量增量非线性模型,即模型除给出堆石体积模量K和剪切模量G的表达式外,对剪应力产生的体变和平均主应力产生的剪切应变也采用了交叉模量J表达。采用粒子群优化算法通过全量本构关系曲线确定增量模型参数。通过对试验数据的拟合发现,三模量模型可以较好地反映堆石料的应力与变形特性。

Three-modulus incremental nonlinear model of rockfill under paths of constant stress ratio

It was indicated by the existing researches that the principal stress ratio in the stress path of rockfill dams kept constant during the period of dam construction.According to the drained triaxial tests under the path of constant stress ratio,a three-modulus incremental nonlinear model was proposed.It could not only provide functional expressions for bulk modulus K and shear modulus G,but also consider the volumetric strain due to the shear stress and the shear strain due to the mean stress with the coupling modulus J.The particle swarm optimization algorithm was used to determine the incremental model parameters through the total constitutive relation curves.Compared with the experimentally measured values,the model could provide good predictions of stress and deformation behavior of rockfill materials.