建筑固废再生填料累积变形及临界动应力试验研究  

Experimental investigation of accumulated plastic strain and critical dynamic stress of unbound aggregates recycled from construction and demolition waste

作　　者：孔坤锋 陈锋 肖源杰 姜钰[2] Umar Faruk Aminu 陈宇亮 李志勇 KONG Kunfeng;CHEN Feng;XIAO Yuanjie;JIANG Yu;Umar Faruk Aminu;CHEN Yuliang;LI Zhiyong(Railway Engineering Research Institute,China Academy of Railway Sciences Corporation Limited,Beijing 100081,China;School of Civil Engineering,Central South University,Changsha,Hunan 410075,China;Ministry of Education(MOE)Key Laboratory of Engineering Structures of Heavy-haul Railway,Central South University,Changsha,Hunan 410075,China;Hunan Communications Research Institute Co.,Ltd.,Changsha,Hunan 410015,China)

机构地区：[1]中国铁道科学研究院集团有限公司铁道建筑研究所,北京100081 [2]中南大学土木工程学院,湖南长沙410075 [3]中南大学重载铁路工程结构教育部重点实验室,湖南长沙410075 [4]湖南省交通科学研究院有限公司,湖南长沙410015

出　　处：《岩石力学与工程学报》2023年第11期2820-2831,共12页Chinese Journal of Rock Mechanics and Engineering

基　　金：中国铁道科学研究院集团有限公司基金项目(2022YJ120);国家自然科学基金资助项目(52178443);国家重点研发计划项目(2019YFC1904704)。

摘　　要：建筑固废用作粒料基层填料的资源化回收利用可从环境、经济和社会等各方面受益。重复交通荷载作用下粒料基层永久变形的逐渐累积可导致车辙和开裂等路面病害,从而降低其使用寿命。通过循环加载三轴试验研究建筑固废再生粗粒土填料在不同应力状态下的塑性变形特性,并通过设计5种不同级配的试样研究颗粒破碎状态对塑性变形和临界动应力的影响规律;进而基于实测数据建立可综合考虑颗粒破碎状态和应力水平的累积塑性应变和临界动应力预测模型。试验结果表明,再生骨料的轴向累积应变随围压的增大或动应力幅值的降低而逐渐减小;颗粒破碎程度的增大削弱了试样抵抗塑性变形的能力。所建立的累积塑性应变预测模型克服了不同级配条件下累积塑性应变计算模型参数的分散性;基于安定理论提出的临界动应力经验公式为合理评估交通荷载作用下再生粗粒土填料的动力稳定性提供了理论依据。Recycling construction and demolition waste(CDW) in the construction of transportation infrastructure can benefit from various environmental,economic and social aspects.The gradual accumulation of permanent deformation of the granular structural layer under traffic loading may lead to rutting,cracking,and other diseases of the pavement,thus reducing its service life.In this paper,the plastic deformation characteristics of coarse-grained soil filler recycled from CDW under different stress states were studied by repeated-load triaxial tests,and the influence law of particle breakage state on plastic deformation and critical dynamic stress was investigated by designing five different graduation specimens.The prediction models of accumulated plastic strain and critical dynamic stress were established based on the measured data,which can comprehensively consider the particle breakage state and stress level.The test results show that the axial accumulated strain of recycled aggregates gradually decreases with the increase of confining pressure or the decrease of dynamic stress amplitude;the increase of particle breakage weakens the ability of specimens to resist plastic deformation.The established accumulated plastic strain prediction model overcomes the dispersion of the parameters of the accumulated plastic strain calculation model under different gradation conditions.The empirical equation for the critical dynamic stress based on the shake-down theory provides a theoretical basis for the reasonable assessment of the dynamic stability of the recycled coarse-grained soil filler under the action of traffic load.

关 键 词：道路工程 累积塑性应变 循环加载三轴试验 建筑固废再生填料 临界动应力 颗粒破碎 

分 类 号：U41[交通运输工程—道路与铁道工程]