铁路活性粉末混凝土槽形梁的空间作用效应

Spatial Effect on Railway Trough Girder with Reactive Powder Concrete

对32 m铁路活性粉末混凝土槽形梁进行三维有限元分析,计算出不同工况下的剪力滞系数,并对剪力滞规律进行分析,研究表明该梁的剪力滞效应较普通混凝土梁更加明显;对其横向和纵向弯矩的空间效应进行分析,对横向弯矩影响线的研究表明,受空间作用的影响,梁上任意一点受力均会在某一截面产生不可忽略的横向弯矩;对纵向弯矩影响线的研究表明空间作用对活性粉末混凝土槽形梁换算荷载的影响在越靠近端部影响越明显,且该影响不可忽略,所以在设计该种梁时需要在靠近端部位置充分考虑空间作用的影响。

The authors carried out three-dimensional finite element analysis on a 32 m railway trough girder which was made of reactive powder concrete. After working out shear lag coefficients under different load conditions, the rule of shear lag was analyzed, and the results indicated that the shear lag effect in this reactive powder concrete trough girder was larger than that of common concrete girder. Further, the spatial effect on transversal and longitudinal bending moments was analyzed, and the study result on the influence lines of transversal bending moments indicated that, due to the spatial effect, any force on any point of the trough girder would cause transversal bending moment which should not be ignored. Finally, the study result on influence lines of longitudinal bending moments showed that, there was spatial effect on equivalent load in reactive powder concrete trough girder; the closer to the girder end the place was, the more obviously the effect became, which also should not be ignored. Therefore, in the design of this kind of railway girder, the spatial effect on the vicinity of girder end should be taken seriously.