一个考虑颗粒破碎的堆石料弹塑性本构模型  

An elastoplastic model for rockfill materials considering particle breakage

作　　者：陈生水[1] 傅中志[1] 韩华强[1] 彭成[1] 

机构地区：[1]南京水利科学研究院,江苏南京210029

出　　处：《岩土工程学报》2011年第10期1489-1495,共7页Chinese Journal of Geotechnical Engineering

基　　金：国家自然科学基金项目(90815024);国家重点基础研究发展规划项目(2007CB714103);水利行业公益性专项经费项目(201001034;200801014);"十一五"国家科技支撑计划专题项目(2009BK56B02)

摘　　要：基于广义塑性理论建立了一个考虑堆石料颗粒破碎的弹塑性本构模型。模型采用随平均应力增加而减小的峰值摩擦角和特征点摩擦角来反映堆石料因颗粒破碎而表现出的峰值应力比与剪胀应力比的非线性,在此基础上确定塑性流动和加载方向向量;运用指数型压缩函数建立依赖于体积应变和平均应力的压缩参数λ,并构造随平均应力与剪应力水平而变化的塑性模量表达式。模型共有8个参数,均可通过等向或单向压缩和三轴压缩试验确定。为验证本文模型的合理性,依据试验资料确定了3种不同堆石料的本构模型参数,并对典型三轴压缩试验进行了模拟。3种材料的模型预测结果与试验数据均吻合良好,表明本文模型可合理反映了颗粒破碎对堆石料强度与变形特性的影响。An elastoplastic constitutive model considering the particle breakage is proposed for rockfill materials within the framework of generalized plasticity.In the model,both the peak friction angle and the characteristic friction angle decrease with the increase of the mean stress so that the nonlinear dependence of the peak stress ratio and the dilatancy stress ratio on the mean stress is captured.The plastic flow direction and the loading direction are then formulated using the above characteristic stress ratios.Another feature of the model is the adoption of the exponential compression equation,based on which the representation of a volumetric strain-dependent and pressure-dependent compression index λ is established so as to formulate the plastic modulus,which is a function of the mean stress and the shear stress level.There are totally 8 parameters in the model,all of which can be determined by isotropic,oedometric and triaxial compression tests.To check the validity of the model,the parameters of three rockfill materials are calibrated based on the experimental data,and the typical triaxial compression tests are modelled.Satisfactory agreement between the numerical and experimental results confirms the capability of the proposed model in capturing the influences of the particle breakage on the strength and deformation behaviour of rockfill materials.

关 键 词：堆石料 颗粒破碎 广义弹塑性本构模型 

分 类 号：TU47[建筑科学—结构工程]