有轨电车嵌入式轨道路基不均匀沉降限值研究OA北大核心

In order to determine the specific threshold value of uneven settlement of subgrade under embedded rail track of tram,a coupled dynamic model of tram-embedded rail track-subgrade considering uneven settlement of subgrade is proposed according to the multi-rigid body dynamics and finite element method.The influence of subgrade settlement amplitude and wavelength on the geometry of embedded rail track under self weight load is investigated in detail.And the subgrade settlement wavelength that is sensitive to the dynamic responses of tram vehicle and track structure is identified.Then the threshold value of uneven settlement of subgrade is obtained on the basis of the fatigue life of track slab.The results show that,under the action of self-weight load,the following deformation curve of rail in the area of uneven settlement of cosine subgrade also presents cosine-like shape,which is basically the same as that of ballastless track supported by ordinary fasteners.Secondly,with the increase of the settlement wavelength,the vertical acceleration of the car body and the dynamic responses of the embedded rail track show a trend of first increasing and then decreasing.When the subgrade settlement wavelength is 10 m,the vertical acceleration of the car body,the dynamic displacement of the rail,the dynamic displacement of the track slab and the bending stress of the track slab all get the maximum value,which indicates that the sensitive subgrade settlement wavelength is 10 m.Finally,in order to ensure the 60-year service life of the embedded rail track of tram,it is recommended to strictly control the differential settlement of subgrade with wavelength below 10m,and the corresponding settlement amplitude of differential settlement of subgrade with wavelength of 20m shall not be greater than 24 mm.