双排栓钉型钢混凝土组合结构大偏心受压性能分析

Performance Analysis of Steel-concrete Composite Structures with Double-row Shear Studs under Large Eccentric Compression

  • 摘要: 为提高隧道初期支护结构在偏心受压条件下的承载性能,提出一种在型钢腹板双排布设栓钉剪力件的型钢-混凝土组合结构。通过开展不同加载偏心距下的大偏心加载试验,并结合数值模拟方法,系统分析该组合结构的承载特性及不同偏心距对结构承载能力的影响。研究结果表明:在自然粘结工况下,当大偏心距分别为0.5h和0.7h时,构件受压侧和受拉侧均出现裂缝并伴有混凝土剥落,导致构件结构整体完全丧失承载能力;而在型钢腹板布设双排栓钉剪力件能有效抑制型钢与混凝土接触界面间的滑移,使构件裂缝扩展范围相较于自然粘结工况条件下减小,结构整体承载性能提升;在0.5h与0.7h偏心距下,自然粘结构件的荷载位移曲线变化一致,加载后期构件承载力能维持在极限承载力的78%;而设置双排栓钉的构件荷载位移曲线变化也一致,加载后期构件承载力能维持在极限承载力的89%,且两种偏心距下的构件侧向挠度减小幅度相似,表明双排布设栓钉剪力件的构件其承载性能与韧性没有受到大偏心距变化的影响;数值模拟分析也进一步表明,大偏心距增加的情况下双排布设栓钉剪力件的构件相比自然粘结构件承载性能会不断加强,验证了该组合结构可以很好地适用于隧道初期支护设计。

     

    Abstract: To improve the load-bearing performance of tunnel initial support structures under eccentric compres? sion, a new type of steel-concrete composite structure with double-row shear studs arranged on both sides of the steel web was proposed. Large eccentric compression tests were carried out under different eccentricities, and finite element simulations were used to analyze the load bearing characteristics of the composite structure and the influence of eccentricity variation on its performance. The results show that under natural bonding conditions, when the large eccentricity reaches 0.5h or 0.7h, cracks appear on both the compression and tension sides of the component, accompanied by concrete spalling, leading to complete failure of the structure. In contrast, the use of double-row shear studs significantly inhibits the slip at the steel-concrete interface, reduces crack propagation, and enhances the overall bearing capacity of the structure. For natural bonding components, the load-displacement curves exhibit similar trends under both 0.5h and 0.7h eccentricities, with the post-load bearing capacity maintained at 78% of the peak load. For components with double-row shear studs, the curves are also consistent, with the post-load capacity maintained at 89% of the peak load. Moreover, lateral deflection is reduced to a similar extent in both eccentricity conditions, indicating that the bearing performance and ductility of the studded members are not significantly affected by large eccentricity variations. Numerical simulations further confirm that the bearing capacity of studded composite members continues to improve with increasing eccentricity, validating the applicability of this structural form in tunnel initial support design.

     

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