BRT公交车制动状态下沥青铺面受力特征

发布时间：2018-10-30 11:47

【摘要】：为了揭示桥面铺装动态荷载下的力学响应规律,以成都某高架混凝土桥沥青铺装工程为依托,以BRT公交车进站制动情况为荷载背景,采用数值模拟分析方法,结合正交试验数值分析结果,进行了桥面铺装方案的结构优化比选.以正交试验得出的优选方案为对象,进一步分析了车辆移动速度对BRT停靠站刹车减速段桥面铺装体系的受力影响,解释了其作用机理.研究表明:振动冲击与作用时间的综合作用导致铺装层竖向变形和剪应力响应存在"临界速度"的现象;不同初始车速下,各轴轮印处面层弯拉应力及剪应力存在短时快变的正负应力交互作用;在制动荷载作用下,表层剪应力较大,并在初始速度60 km/h制动工况下达到极值;在靠近公交站台等车辆制动或加速相对频繁的路段,应特别注意提高铺装层的抗剪切及抗疲劳能力,同时加强层间粘结.
[Abstract]:In order to reveal the mechanics response law of bridge deck pavement under dynamic load, based on asphalt pavement engineering of an elevated concrete bridge in Chengdu, and taking the braking condition of BRT bus entering station as load background, numerical simulation analysis method is adopted. Based on the results of numerical analysis of orthogonal test, the structural optimization and selection of bridge deck paving scheme are carried out. Taking the optimal selection scheme obtained by orthogonal test as the object, the influence of vehicle moving speed on the bridge deck pavement system in braking deceleration section of BRT station is further analyzed, and the mechanism of its action is explained. The results show that the combined action of vibration shock and action time leads to the phenomenon of "critical velocity" in the vertical deformation and shear stress response of pavement. At different initial speeds, there is a short time and fast change interaction between the bending tensile stress and shear stress in the surface layer of each axle wheel, the surface shear stress is larger under braking load, and the maximum value is reached under the initial speed of 60 km/h braking condition. Special attention should be paid to improving the anti-shear and anti-fatigue ability of the pavement and strengthening the bond between the layers in the sections where vehicles brake or accelerate relatively frequently near the bus station.
【作者单位】：西南交通大学土木工程学院;西南交通大学道路工程四川省重点实验室;
【基金】：国家自然科学基金资助项目(51378438) 成都市交通科技资助项目(JHFDD-JSFW-001)
【分类号】：U443.33

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