基于颗粒流分析的水利枢纽工程中沥青混凝土材料破坏试验研究

Experimental Research on the Failure of Asphalt Concrete Material in Water Conservancy Project based on Particle Flow Analysis

使用颗粒流分析软件PFC模拟计算了沥青混凝土材料三轴加载全过程试样应力应变特征。分析了试样三轴峰值应力、变形受围压影响增大效应,变形全过程历经压缩-扩容两阶段,围压增大会导致扩容点滞后,获得了试样破坏全过程裂隙演化特征,残余应力阶段贯通有大裂纹,倾角45°。分析了径高比对试样峰值应力影响,峰值应力与径高比关系呈正相关,但改变直径参数对轴向变形影响较小,且应力差异在屈服塑性阶段才显著。研究了围压增大可促进径高比对试样强度增长效应的影响,线弹性模量与围压关系呈负相关,且与径高比关联性不强。

In order to study the triaxial mechanical characteristics of asphalt concrete materials in a water conservancy pro-ject,the stress and strain characteristics of the sample during the whole process of triaxial loading are simulated and calcu⁃lated with the aid of the particle flow analysis software PFC.The increasing effect of the confining pressure on the triaxial peak stress and deformation of the sample is analyzed.The whole process of deformation undergoes two stages of compre-ssion and dilatancy while the increase of confining pressure would lead to the lag of dilatancy point and the maximum com⁃pression volumic strain would increase.The characteristics of the fracture evolution during the whole failure process of the sample are obtained.Large cracks are formed in the residual stress stage and the inclination Angle is 45°.The influence of the diameter-to-height ratio on the peak stress of the specimen is analyzed.The peak stress and the diameter-to-height ra⁃tio are positively correlated,but changing the diameter parameter has little effect on the axial deformation and the stress di-fference is more significant at the yield plastic stage.The increase of confining pressure can promote the influence of the dia-meter-to-height ratio on the strength growth of the sample,but the elastic modulus is negatively correlated with the confin⁃ing pressure,and the correlation with the diameter-to-height ratio is not strong.This paper can provide a certain reference for the understanding of mechanical properties of asphalt concrete materials in water conservancy projects.