预应力对截面不对称槽形梁空间受力的影响分析

Influence Analysis of Prestress on Spatial Force of Asymmetrical Groove Beam with Cross Section

为了研究预应力对截面不对称开口薄壁连续梁空间受力的影响,以某单侧悬挑人行道的不对称截面槽形混凝土连续梁为依托,采用有限元软件ANSYS建立实体模型,分析计算仅考虑自重荷载及考虑不同布束方式的预应力荷载作用时,槽形梁剪力滞效应及横向受力情况。通过对比分析可以发现:自重作用下槽形梁剪力滞效应明显且两侧受力不平衡,预应力荷载对剪力滞效应有明显平抑作用,将靠近人行道侧腹板增加5%预应力,改善行车道板两侧受力不均衡情况;在腹板及行车道板处布置横向预应力能有效调整截面横向受力情况,但人行道部分仍为受拉应力,将横向预应力延伸到人行道后结构整体受力安全,故建议在人行道布置横向预应力。

In order to study the effect of prestress on the spatial stress of asymmetric open section thin-walled continuous beam,the asymmetrical section concrete continuous beam with one side suspended sidewalk is taken as the background.The finite element software ANSYS is used to establish the solid model to analyze and calculate the shear lag effect and transverse force condition of slot girders,considering only the self-weight load and the prestressing load considering different modes of beam arrangement.Through comparative analysis,it can be found that the shear lag effect of the grooved beam is obvious under the action of self-weight,the force on both sides is unbalanced,and the prestress load should have a significant stabilizing effect on the shear lag effect.The 5%prestress is added near the sidewalk side web,and the force imbalance between the two sides of the lane can be changed.The Transverse Prestress at the web and lane can effectively adjust the transverse force of the section,but the sidewalk part is still tensile stress.When the transverse prestress extends to the sidewalk,the whole structure is safe.Therefore,it is suggested to arrange transverse prestress on the sidewalk.