Experimental and numerical analysis on interface damage of slab track under freeze-thaw cycles
任娟娟 1杜威 1叶文龙 1许雪山 2邓世杰1
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作者信息
1. School of Civil Engineering,Southwest Jiaotong University,Chengdu 610031,China;Key Laboratory of High-speed Railway Engineering of Ministry of Education,Southwest Jiaotong University,Chengdu 610031,China
2. China Railway First Survey and Design Institute Group Co.,Ltd.,Xi'an 710043,China
The interface of slab track laid in cold regions is prone to debonding under the coupling of freeze-thaw cycles and temperature loads.Based on the composite specimen tests,the parameters of cohesive zone model were obtained and used in a simulation model of CRTS Ⅲ prefabricated slab track to study the interlayer damage.The results show that 1)the digital image correlation(DIC)technique can accurately capture the strain field changes on the interface of composite specimens under splitting and shear loading;2)when the temperature gradient is-40 ℃/m-60 ℃/m,the interface damage of the slab track is minimal and presents different patterns of expansion under positive and negative temperature gradients,each corresponding to damage of the cohesive element dominated by shear stress and normal tensile stress,respectively;3)the reduction of the elastic modulus at the concrete base after freeze-thaw inhibits interface damage and leads to a higher starting temperature gradient load,but cracking can occur on the concrete base after 150 freeze-thaws.For this reason,in the light of damage control of both the interface and concrete base,the elastic modulus of the concrete base is 54％or over that without freeze-thaw cycles.
关键词
板式无砟轨道/冻融循环/粘结性能/内聚力模型/界面损伤
Key words
CRTS Ⅲ prefabricated slab track/freeze-thaw cycle/bonding performance/cohesive zone model/interface damage
万方数据