浇筑式沥青混凝土动应力-应变试验及影响因素敏感性分析

Stress-strain Experiment and Sensitivity Analysis of Influencing Factors on Pouring Asphalt Concrete

以新疆某心墙浇筑式沥青混凝土材料为例,对其进行动三轴试验,研究了浇筑式沥青混凝土动应力-应变骨干曲线的变化规律及不同围压、主应力比和振动频率对浇筑式沥青混凝土动应力-应变骨干曲线的影响,并基于正交设计方案,以动应力为考察指标,分别采用极差和方差分析法分析了围压、主应力比和振动频率的敏感性。试验结果表明,浇筑式沥青混凝土材料动应力-应变骨干曲线变化基本符合双曲线规律,围压和主应力比对动应力-应变骨干曲线的影响较大,随围压和主应力比的增加,沥青混凝土的动强度明显增大;振动频率对浇筑式沥青混凝土材料动应力-应变骨干曲线的影响较小,不同频率下的骨干曲线均集中于狭窄的分布带内,高振动频率的动强度略大于低频下的动强度。围压和主应力比对动应力的影响比较显著,是影响动应力的主要因素,振动频率对动应力的影响不显著,影响因素的敏感性依次为围压、主应力比和振动频率。

Based on the core wall material of pouring asphalt concrete in Xinjiang,the material was done the dynamic triaxial experiment.The change rule was studied on dynamic stress-strain backbone curve of pouring asphalt concrete and the influence rule was researched on different confined pressure,principal stress ratio and vibration frequency to the dynamic stress-strain backbone curve of pouring asphalt concrete.Using orthogonal design method for experiment,taking dynamic stress as examining index,the range and variance analysis method were respectively adopted to analyze the sensitivity of confined pressure,the principal stress ratio and vibration frequency.Test results show that the change of dynamic stress-strain backbone curve of pouring asphalt concrete material largely is in line with hyperbolic rule.Confined pressure and the principal stress ratio have great influence on the dynamic stress-strain backbone curve.With the increase of confined pressure and the principal stress ratio,the dynamic strength of asphalt concrete significantly increases.It is poor influence on vibration frequency to the dynamic stress-strain backbone curve of pouring asphalt concrete material.The backbone curves for different frequency are concentrated in a narrow distribution zone.The dynamic strength of high frequency is slightly bigger than under low frequency.The influence of confined pressure and the principal stress ratio are more significant on dynamic stress,and are the main factors which influence the dynamic stress.The influence of vibration frequency on dynamic stress is not obviously.The sensitivity order of influencing factors are the confined pressure,the principal stress ratio and vibration frequency.