不平整条件下过渡段车辆运行平稳性

Vehicle Smoothness Through Highway Bridge Approach Under Condition of Pavement Roughness

以内蒙古110国道改扩建项目为背景,建立了路桥过渡段三维模型及七自由度整车模型,分析了当路面出现波浪形不平顺以及左右车轮处路面沉降不均等破坏类型时,以车体垂向加速度、车轮动荷载系数以及前后轮垂向位移差作为评价指标,综合评价搭板对路面不平整的改善效果。结果表明:无搭板时,随着路面等级从A降低到C,车体最大垂向加速度由0.96m/s^2增大到3.78m/s^2,前后轮最大垂向位移差由20.5mm增大至114.8mm;设置搭板后,最大垂向加速度由0.87m/s^2增大到2.93m/s^2,前后轮最大垂向位移差由18.7mm增大到34.2mm;搭板的设置可以将前轮动荷载系数降低到更高一级路面的水平。在左右车轮所处路面沉降不均时,由无搭板到板厚30cm时,车体最大垂向加速度由1.92m/s^2降低到1.13m/s^2;板厚由30cm增大到45cm时,最大垂向加速度只从1.13m/s^2降低到1.03m/s^2,均处在人体不舒适的范围之内。可见,当左右车轮所处路面沉降不均时,搭板的改善效果不显著,需要采取其他工程补救措施。

Against the background of the Inner-Mongolia 110 national highway reconstruction project and with the three-dimensional model of transition section and seven DOFs vehicle model is established,the influence of slabs on the pavement roughness is comprehensively analyzed when types of damages are done to the pavement,such as wavy irregularity and uneven settlement where left and right wheels go through,by taking car vertical acceleration,the wheel dynamic loading coefficient,and the front-rear wheel′s vertical displacement difference as the evaluation criteria.The results are as follows:without any slabs,the maximum vertical acceleration increases from 0.96 m/s2 to 3.78 m/s2 with the road grade reducing from A to C,and the maximum vertical displacement difference between front and rear wheels increases from 20.5 mm to 114.8 mm.While with slabs,the maximum vertical acceleration increases from 0.87 m/s2 to 2.93 m/s2,and the maximum vertical displacement difference between front and rear wheels increases from 18.7 mm to 34.2 mm,which indicates that the slabs intend to make the front wheel dynamic load coefficient reduce to a lower level the same as that on the higher grade road.But under the condition of uneven settlement road where left and right wheels go through,with the slab′s thickness increasing from 0 cm to 30 cm,the maximum vertical acceleration of car body reduces from 1.92 m/s2 to 1.13 m/s2.When the slab′s thickness increases from 30 cm to 45 cm,the acceleration only reduces from 1.13 m/s2 to 1.03 m/s2,which is within the scope of uncomfortable standard of human body.Therefore,When the pavement where left and right wheels go through suffers from uneven settlement,the slabs have no significant effects on improving the vehicle smoothness,which requires other remedial measures.