现浇箱梁顶板预留孔形状及位置的优化分析

Optimization Analysis of the Position and the Shape of the Pre-setting Hole in Cast-in-situ Box Girder Top Slab

文章分析了某大桥预应力混凝土箱梁施工过程中,顶板开设预留孔所引起的孔口附近顶板破坏现象,并在考虑不同开孔位置及开孔形状的情况下,使用ANSYS有限元程序对节段进行了整体式分析。结果表明开孔位置和孔的形状对孔口附近顶板的应力影响很大,同时指出开孔位置应尽量远离纵向预应力孔道,孔的形状应以圆形或带切角的多边形为主,在满足施工中正常使用的前提下尽量缩小孔的尺寸。

This paper analyzes the phenomena of top slab failure near the hole when the reserved hole is pre-set during the construction process of the bridge, furthermore in consideration of different hole position and shape, integral analysis of segment has been made using the ANSYS finite element program. The results show that pre-setting hole position and the shape have the strong influence to the stress of top slab near the hole and simultaneously proposed that the pre-setting hole should be positioned as far from prestressed passageway as possible. The holes should be in the circular shape or the polygonal with corner cut primarily. Under the premise of construction, the dimensions of hole should be reduced as far as possible.