Design of Shear Keys for Precast Segmental Box Girders Based on Bidirectional Evolutionary Structural Optimization Algorithm
This study investigates the load bearing behavior of shear keys in the cast-in-place(CIP)stitches of the precast segmental box girders responding to single load and load combinations.The viaduct carrying a section of the South Fourth Ring Road in Zhengzhou city is used as a case.Considering the load bearing behaviors and functions of the shear keys,finite element models of the typical box girder segments were developed in Abaqus,together with the bidirectional evolutionary structural optimization(BESO)algorithm,to figure out the arrangements of shear keys under different loading conditions,including unit axial forces,shear forces,torsional moments,bending moments and different load combinations.As per the analysis,the shear keys should be arranged in different places of the box girders under different forces,specifically arranged in top slabs under axial forces,in webs and bottom slabs under shear forces,in junction of top slabs and webs as well as exterior of webs under torsional moments,in top slabs,lower parts of webs and bottom slabs under lateral bending moments,and in the flanges of the top slabs under vertical moments.Under the combined action of axial and shear forces,especially when the proportion of the shear forces is less than 50％,the axial forces govern the arrangement of shear keys.When the proportion of shear forces reaches 95.24％,the shear forces dominate the arrangement of shear keys.Under the combined action of bending moments and shear forces,with the proportion of shear forces exceeding 4.76％,the shear forces control the arrangements of the shear keys,while the lateral bending moments play a dominant role when the proportion of shear forces is less than 0.50％.Under the combined action of torsional moments and shear forces,when the proportion of shear forces surpasses 0.10％,shear forces dictate the arrangement of shear keys.The types of loads and load combinations are critical to the arrangement of shear keys.The arrangement of shear keys in the CIP stitches of precast segmental box girders should be designed considering the actual loading conditions of the shear keys in different locations.
segmental box girdershear key arrangementbidirectional evolutionary structural optimization algorithmforce transfer mechanismsingle loadload combinationdesign optimizationfinite element method
万方数据
维普
