重复荷载作用下碎石粒料弹塑性变形显著非线性阶段的量化表征  

Quantitative Characterization of Significant Nonlinear Stage of Elasto-plastic Deformation of Unbound Granular Materials under Repeated Loads

作　　者：李宁 马骉[3] 王杰[1] LI Ning;MA Biao;WANG Jie(Key Laboratory of Road Structure and Material of Transport Industry,Research Institute of Highway,Ministry of Transport,Beijing 100088,China;School of Civil Engineering,Xi'an University of Architecture and Technology,Xi'an Shaanxi 710055,China;Key Laboratory of Special Area Road Engineering of Ministry of Education,Chang'an University,Xi'an Shaanxi 710064,China)

机构地区：[1]交通运输部公路科学研究院道路结构与材料交通运输行业重点实验室,北京100088 [2]西安建筑科技大学土木工程学院,陕西西安710055 [3]长安大学特殊地区公路工程教育部重点实验室,陕西西安710064

出　　处：《公路交通科技》2023年第4期68-77,87,共11页Journal of Highway and Transportation Research and Development

基　　金：中国博士后科学基金项目(2019M663649);道路结构与材料交通运输行业重点实验室(交通运输部公路科学研究院)开放基金项目(0220KY99ZY0052-01);陕西省自然科学基金青年项目(2022JQ-560)。

摘　　要：为了确定重复荷载作用下碎石粒料弹塑性变形的显著非线性表征阶段,采用精密非黏结材料分析仪(PUMA)进行了100000次重复荷载试验,分析了3种碎石粒料在4种荷载强度下的弹性应变、塑性应变及塑性应变率,借助3种安定准则探讨了不同荷载强度下3种碎石粒料的安定状态,对重复荷载作用下碎石粒料的弹性应变与塑性应变近似线性阶段进行了参数分析,确定了重复荷载作用下碎石粒料弹塑性变形的显著非线性表征阶段。结果表明:当采用Werkmeister安定准则判定时,碎石粒料变形处于Range B安定区间,而采用Chen等和Xiao等提出的安定准则进行判定时,碎石粒料变形处于Range A安定区间,采用Xiao提出的安定准则进行判定时,第1阶段和第2阶段变形的分界点变化规律不明显,且不存在明显的第3阶段;弹性应变和塑性应变线性阶段拟合的斜率参数随起始点位置变化显著,且存在趋稳态势,而截距参数随起始点位置变化不明显;起始点为20000次的线性拟合参数与起始点为30000次、40000次的线性拟合参数相近,且20000次荷载的弹塑性应变占100000次弹塑性应变的93%以上,确定采用前20000次荷载作为碎石粒料显著非线性变形的表征阶段,有利于提高碎石粒料变形行为研究的高效性和经济性。In order to determine the significant nonlinear characterization stage of elastic-plastic deformation of unbound granular materials under repeated loads,100000 times repeated load test are carried out by using precision unbound materials analyzer(PUMA).The elastic strain,plastic strain and plastic strain rate of 3 forms of unbound granular materials under 4 loading intensities are analyzed.The shakedown states of 3 forms of unbound granular material are explored under different loading intensities by using 3 shakedown criteria.Under repeated Loads,the parametric analyses of the approximate linear phases of the elastic and plastic strain are carried out,and the significant nonlinear characterization stages of elastic and plastic deformation of unbound granular materials are determined.The result shows that(1)When using Werkmeister shakedown criterion for judgment,the unbound granular material deformation is in Range B,while it is in Range A when using the shakedown criteria proposed by Chen and Xiao,et al.When using Xiao's shakedown criterion for judgment,the variation of boundary point between the first and second stages is not obvious,and there is no the third stage.(2)The slope parameters of linear fitting stage of elastic and plastic strain significantly vary with the position of start point,and tend to be stable.However,the intercept parameters do not change obviously with the position of start point.(3)The linear fitting parameters at 20000 repetitions are similar to which at 30000 and 40000 repetitions,and the elastic and plastic strains at 20000 repetitions account for more than 93%of 100000 repetitions.It is determined that the first 20000 repetitions can be used as the characterization stage of significant nonlinear deformation of unbound granular materials,which is benefit for improving the efficiency and economy of deformation behavior research of unbound granular materials.

关 键 词：道路工程 弹塑性变形 试验研究 重复荷载 碎石粒料 非线性阶段 

分 类 号：U416.214[交通运输工程—道路与铁道工程]