基于现场大型承载试验的原级配筑坝堆石料力学参数反演研究

基于水布垭面板坝的现场大型承载试验成果,采用基于IGA的反演方法,研究了栖霞组灰岩、茅口组灰岩两种原级配筑坝堆石料的邓肯E–B模型参数。结果表明:在相同应力加载路径条件下,现场原级配堆石料比经过缩尺后的室内三轴试验试样具有更大的体积变形和更高的切线弹性模量,两者的力学性状存在较大差别。对栖霞组原级配灰岩堆石料的回弹模量参数反演分析得到K ur约为K值的2倍,而nu r远大于邓肯建议的直接引用加载时的弹性模量指数n值。宜加强现场原级配粗粒堆石料的力学性质研究,为超高堆石坝的建设提供更为可靠的理论依据。

Back analysis of mechanical parameters of naturally graded rockfill materials based on large-scale loading plate tests

Based on the results of large-scale loading plate tests of Shuibuya Dam,the Duncan-Chang E-B model parameters under two kinds of naturally graded rockfill materials,Qixia group limestone and Maokou group limestone,are studied by use of the back analysis method based on the IGA.The test results indicate that under the same loading path,the volumetric deformation and tangent modulus of naturally graded rockfill materials are larger than those of the scaled indoor triaxial tests,and there are distinct differences between them in mechanical property.Kur,obtained from the back analysis of the resilience modulus of naturally graded rockfill on Qixia group limestone,is approximately twice as K,however,nur is much larger than the elastic modulus index n proposed by Duncan.The researches on mechanical property of naturally graded coarse rockfill materials should be strengthened to provide a more reliable theoretical basis for the construction of super-high rockfill dams.