基于不同行驶状态下桥面沥青铺装层间力学行为研究

Study on Mechanical Behavior of Bridge Asphalt Pavement Interlayer Under Different Driving States

为探究车辆行驶状态(匀速、制动和加速)和层间接触差异对连续箱梁桥沥青铺装结构力学行为的影响规律,分别以接触模型和连续模型表征层间联结特性建立桥面沥青铺装结构仿真模型,以车辆行驶状态下桥面沥青铺装结构力学响应差异进行层间联结模型比选;对比分析车辆行驶状态和层间摩擦系数μ(0.0、0.2、0.4、0.6、0.8)对桥面沥青铺装结构的力学响应影响规律。结果表明,层间联结采用接触模型时所得结构层各响应指标值均大于连续模型,接触模型能更好地反映桥面沥青铺装结构层间真实联结状态。相同层间摩擦系数下,车辆制动和加速行驶状态下的结构层各动态响应指标均大于匀速状态,其中纵向剪应力增涨幅度最明显,为匀速行驶状态下的2倍左右;随着层间摩擦系数的增加,铺装结构黏结层的S 11、S 22、S 33、S 12减小,纵向剪应力S 23增加。车辆在加速或制动过程中会对桥面沥青铺装结构层间黏结产生较大的损伤,因此在桥梁限速区间采取措施适当地提高层间黏结力,有利于减缓沥青铺装层层间滑移破坏。

In order to explore the influence of interlayer contact difference and vehicle driving states(uniform speed,braking,and acceleration)on the mechanical behavior of asphalt pavement of continuous box girder bridge,the contact model and the continuous model were used to characterize the interlayer connection to construct the simulation model,and the difference of the mechanical response of the bridge asphalt pavement under the vehicle driving state was used to compare the interlayer connection model.In addition,the influence of vehicle driving state and interlayer friction coefficients(0.0、0.2、0.4、0.6、0.8)on the mechanical response of bridge asphalt pavement was comparatively analyzed.The results showed that the response index values of the structural layer obtained by the contact model are greater than those of the continuous model,which can better reflect the true connection state between the layers of the bridge asphalt pavement.Under the same interlayer friction coefficient,the dynamic response indexes of the structural layer under the braking and accelerating driving conditions of the vehicle are greater than those under the uniform driving condition.Among them,the increase of longitudinal shear stress is the most obvious,which is 2 times that under the uniform driving condition.The S 11,S 22,S 33,and S 12 of the bonding layer of the pavement structure decrease with the increase of interlayer friction coefficient,and the longitudinal shear stress S 23 increases.In the process of acceleration or braking,the vehicle will cause great damage to the interlayer bonding of the bridge asphalt pavement.Therefore,measures should be taken to properly improve the interlayer bonding force in the speed limit interval of the bridge,which is conducive to slowing down the interlayer slip failure of the asphalt pavement.