钢-混凝土组合箱梁底板局部屈曲失稳分析

Analysis on local buckling instability at the bottom of steel-concrete composite box beams

针对钢-混凝土组合箱梁负弯矩区底板在受压状态下的力学性能,建立箱梁底板在受压作用下的局部稳定性计算模型。通过对一般箱梁底板在受压作用下的局部稳定性计算和对箱梁底板焊接栓钉并浇筑一定厚度的混凝土板的局部稳定性的计算进行对比分析。结果表明:在受压状态下现浇混凝土板可以有效防止发生局部屈曲失稳,降低箱梁底板的应力,提高弯矩区混凝土梁的极限承载能力。

Tests have been carried out to study the mechanical property when the negative bending region of combination of steel-concrete composite box beams is under compression.This paper emphasizes the discussion of the computation model of the local stability when box beams is under compression.By comparing the local stability of box beams when under compression with the box beams which is welding studs,pouring concrete slab of certain thickness,this paper is to provide the reference for the optimization design of the bottom slabs of the negative bending region of combination of steel concrete composite box beams.Results showed that cast-in-place concrete slab in compression state can effectively prevent the occurrence of local buckling instability;it can reduce the stress of the concrete slab and improve the negative bending region of concrete beams of the ultimate bearing capacity.