Comparison of shear performance of in-service hollow slab beams based on abandoned standards
LU Qiaoqiao
SONG Shuqin
ZHAO Kunpeng
LIANG Maojing
Abstract：To analyze the shear resistance performance of the existing old hollow slab beam bearing shear zone,to ensure the safety and durability of the bridge,considering the factors such as the section form of the slab beam,the layout of ordinary steel bars,the arrangement of prestressed steel bars,the strength of concrete materials,and the combination of load effects,the software MIDAS CIVIL is used to design hollow slab beams S1 and S2 according to Code for Design of Highway Reinforced Concrete and Prestressed Concrete Bridges and Culverts JTJ 023-1985 and JTG D62-2004,and to perform shear analysis under static loads and moving loads;according to the scale ratio of 1:4,experimental beams T1 and T2 are designed and manufactured according to the requirements of JTJ 023-1985 and JTJ D62-2004,and loaded in a stepwise manner to the normal service limit state and ultimate limit state design loads specified in JTJ D62-2004 until the failure of the experimental beams.Research on the shear resistance performance of the hollow slab beams designed according to JTJ 023-1985 and JTJ D62-2004 under the lane load effects specified in Specifications for Design of Highway Reinforced Concrete and Prestressed Concrete Bridges and Culverts(JTG 3362-2018),and comparison of the results of finite element model analysis with the results of scaled model loading tests.The results show:1)Under constant load,the shear force on S1 is generally slightly smaller than S2,the maximum shear stress of hollow slab beams S1 and S2 increases significantly with the increase of the combined effect of lane load in JTG 3362-2018,by 26.8％and 16.8％respectively.2)The experimental phenomena of beams T1 and T2 are similar:As the load increases,cracks appear successively at the loading point bottom plate,pure bending zone bottom plate,and shear compression zone,the inclined cracks in the shear compression zone extend as the main cracks,secondary cracks appear near the main cracks,and transverse cracks at the loading point extend to the web plate.3)The deflection of beam T1 is greater than that of beam T2.4)At the beginning of loading,the relationship between the main tensile strain and the load is roughly linear.As the load increases,the main tensile strain in the midspan increases the fastest,followed by the bottom,cracks first appear in the shear compression zone in the middle of the beam,extending to the bottom,the top main tensile strain changes less;the later stage has a larger slope,when the load slightly increases,the strain increase is too fast,and the crack changes greatly.5)Beams T1 and T2 have not reached the failure state when loaded to the design carrying capacity limit state in JTG 3362-2018,the overall safety margin of the slab beams meets the requirements,but the margin is small.6)The deflection and strain verification factors of beams T1 and T2 meet the requirements,but early appearance of cracks in the shear zone will directly affect the durability of bridge usage and reduce the overall stiffness of the bridge.
Keywords：bridge engineeringshear-resistanthollow beam in servicecontrast test
Publication Date：2025-03-30
Online Publishing Date：2026-05-22(First online date of this platform, not the publication date of the document)
Pages：11( 120-130 )