【摘要】 由于邓肯—张EB模型没有考虑颗粒破碎损伤对材料变形及强度的影响,不能模拟堆石料应变软化的缺陷,故将统计损伤理论引入邓肯—张双曲线模型。通过探讨堆石料应力—应变曲线不同阶段损伤变量的规律,描述堆石料的损伤破碎过程,考虑其损伤阈值的影响,建立了邓肯—张修正模型表达式,该模型参数能通过试验数据拟合得出。经过验证,邓肯张修正模型在高围压下能较好的模拟堆石料破碎损伤的全过程,低围压下退化为常规邓肯—张模型。与传统邓肯—张模型、统计损伤模型、弹塑性模型及试验结果相比较,其形式简单、参数少。研究成果可应用于底部围压较大的高堆石坝分析,为堆石坝的设计计算提供参考。更多还原

【Abstract】 As the impact from grain crushing damage on deformation and strength of materials is not considered,Duncan-Chang EB model cannot simulate the strain softening defect of the rockfill materials,the statistical damage theory is introduced into Duncan-Chang hyperbolic model.Through discussion on the law of the damage variables of the different phases of the stress-strain curve of the rockfill materials,description of the damage crushing process of the rockfill and consideration of the impact from the damage threshold of the rockfill materials,the modified Duncan-Chang model is established;for which the parameters can be obtained from the fitting of testing data.Through verification,the modified Duncan-Chang model can better simulate the full process of the crushing damage of rockfill materials under high surrounding pressure,and regress to the conventional Duncan-Chang model under lower surrounding pressure.Compared with the conventional Duncan-Chang model,the statistical damage model and the elastic-plastic model,the model has the merits of simple form and few parameters.The study result can be applied to the high rockfill dam with large bottom surrounding pressure,thus provide a reference for the design calculation of rockfill dam.更多还原