摘要
为揭示罗埠大桥双层SMA铺装层早期病害原因,利用ABAQUS有限元分析软件对钢桥面建立了三维有限元模型,并施加了移动荷载,首先研究了沿行车纵向各典型位置处双层SMA铺装层力学响应,对比分析找出了力学指标的最不利断面;然后研究了3种具有代表性的荷载移动带下双层SMA铺装层力学指标沿横向和竖向的分布规律,揭示了力学指标的最不利位置;最后,基于双层SMA铺装层早期病害原因,对其进行了有针对性的结构优化,进一步对比研究了设置缓冲层的双层SMA铺装层力学响应,并验证了优化后的双层SMA铺装层具有较好的力学结构性能。研究表明:双层SMA铺装层层间滑移病害主要是层间剪应力的“揉搓”作用导致。该“揉搓”作用具有方向相反且峰值间隔时间极短的特点;双层SMA铺装层与钢桥面层间接触条件的恶化,会加速双层SMA铺装层的疲劳开裂,摩擦系数每降低0.2,沥青层拉应变平均增加3.26%;设置缓冲层的双层SMA铺装层层间和自身受剪情况较优化前,有着较为明显的改善;在同等工况下,优化后的双层SMA铺装层层间剪应力和沥青层最大剪应力分别较优化前减少了25%~30%和12%~16%。
In order to reveal the reason for the early disease of the double-layer stone mastic asphalt(SMA)pavement of Luobu bridge,a 3D finite element model was established by ABAQUS finite element analysis software.The mobile load was applied on the model.Firstly,the mechanical response of the pavement layers was studied along the driving longitudinal direction.The most unfavorable section of the mechanics index was compared and found;Then,the distribution rules of mechanical indicators in the horizontal and vertical direction was studied under three representative mobile loads to reveal the most unfavorable position of mechanical indicators;Finally,based on the cause of early disease of double-layer SMA steel bridge pavement,the structure was targeted optimized.The mechanical response with buffer layer was further studied.It was verified that the optimized pavement layer has better mechanical structural performance.Research shows that the inter-layer sliding disease of double-layer SMA steel bridge pavement is mainly caused by"rubbing"of inter-layer shear stress.The“”rubbing"effect has the characteristics of the opposite directions and the short peak interval;That the worse contact conditions of the pavement layer and steel bridge surface layer will accelerate the fatigue and cracking of the paving layer;When the friction coefficient is reduced by 0.2,tensile strain of asphalt layer increase by 3.26%averagely;The shear stress situation of inter-layer and the SMA bridge buffer layers has obvious more improvement than before optimization;Under the same working conditions,the optimized maximum shear stress of the inter-layer and asphalt layer are reduced by 25%~30%and 12%~16%respectively.
作者
王礼根
许文斌
Wang Ligen;Xu Wenbin(Anhui Transport Survey&Design Institute Co.,Ltd.,Hefei 230000,China)
出处
《市政技术》
2024年第1期41-48,54,共9页
Journal of Municipal Technology
基金
引江济淮工程基于耐久性的双层SMA钢桥面沥青铺装层应用关键技术研究(KY220061HF)。
关键词
道路工程
钢桥面铺装
结构优化
数值模拟
移动荷载
road engineering
steel bridge pavement
structure optimization
numerical simulation
mobile load
