摘要
考虑到高速铁路沥青混凝土层在复杂荷载作用下可能出现层间离缝及开裂而导致路基失稳,引入黏弹性内聚力模型模拟底座板与沥青层间黏结-脱黏-分离-开裂的复杂相互作用关系,建立车辆-轨道-路基三维精细化有限元模型,并利用现场推板试验获得层间接触参数,借助基床表层动位移数据验证模型的正确性,系统分析复杂荷载作用下沥青混凝土层的受力性能及裂纹扩展特性。研究结果表明:在正温度梯度作用下,温度敏感区处于底座板边缘有效接触区的边角位置;在负温度梯度作用下,最大应力和应变都较小,且温度敏感区处于底座板有效接触区中部;当温度骤降时,裂纹扩展以张开型裂纹为主;低温场或高温场-列车荷载耦合作用下易出现横向滑移型裂纹;在伸缩缝位置处铺设长度为1.0~1.5 m的复合土工膜可有效地控制层间离缝及裂纹扩展。
Considering that asphalt concrete layer of high-speed railway under complex load may cause interlayer separation and cracking, which results in the instability of roadbed, a viscoelastic cohesion model was established to simulate the complex interactions between the bottom slab and the asphalt layer, including bonding, debonding,separation, and cracking. A three-dimensional refined finite element model of the vehicle-track-subgrade was established. The contact parameters between the layers were obtained using field push plate tests. The correctness of the model was verified by the dynamic displacement data of the bed surface. The mechanical properties and crack propagation types of asphalt concrete layer under complex load were analyzed. The results show that under the effect of positive temperature gradient, the temperature sensitive area is located at the corner of the effective contact area of the bottom slab. Under the effect of negative temperature gradient, the maximum stress and strain are small, and the temperature sensitive area is in the middle of the effective contact area of the bottom slab. When the temperature drops sharply, the crack growth is mainly open-type cracks. Low-temperature or high-temperature field-train load coupling is prone to lateral slip cracks. The composite geomembrane with length of 1.0-1.5 m can effectively control the gap between layers and crack propagation at the expansion joint position.
作者
吕宋
肖宏
张智海
LU Song;XIAO Hong;ZHANG Zhihai(Beijing Key Lab of Track Engineering,Beijing Jiaotong University,Beijing 100044,China;Railway Engineering Research Institute,China Academy of Railway Sciences Co,Ltd.,Beijing 100081,China)
出处
《中南大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2020年第10期2893-2905,共13页
Journal of Central South University:Science and Technology
基金
国家自然科学基金资助项目(51978045)
高速铁路轨道技术国家重点实验室开放基金资助项目(2017YJ166)。
关键词
高速铁路
沥青混凝土层
内聚力模型
裂纹扩展
复合土工膜
high-speed railway
asphalt concrete layer
cohesion model
crack propagation
composite geomembrane
作者简介
通信作者:肖宏,博士,教授,从事铁道工程研究,E-mail:xiaoh@bjtu.edu.cn。
