钢纤维混凝土管片不同接头型式力学性能研究

Mechanical Behavior of Steel Fiber Reinforced Concrete Segments with Different Joint Configurations

  • 摘要: 为研究钢纤维混凝土管片不同型式接头的力学性能特征,采用经室内试验验证的数值模拟方法,建立弯螺栓、斜螺栓以及双层螺栓等型式的钢纤维混凝土管片平直接头模型,重点分析钢纤维混凝土管片接头的抗弯刚度、极限承载能力、破坏特征。研究结果表明,钢纤维混凝土管片接头的极限承载力高于素混凝土管片接头与钢筋混凝土管片接头,在正弯矩工况下提升显著;弯矩增长阶段,钢筋混凝土管片接头刚度最大,钢纤维混凝土管片接头和素混凝土管片接头刚度相近,说明钢纤维的加入对管片接头刚度的影响有限;与单螺栓设计相比,双层螺栓设计可提高接头极限承载力和接头刚度,正弯矩工况下接头刚度最大可提升398%(弯螺栓)和225%(斜螺栓),负弯工况下极限承载力提升明显(约12%~14%);斜螺栓接头的极限承载力和抗弯刚度介于弯螺栓接头和双层螺栓接头之间,适用于一般工程;双层螺栓接头在负弯矩作用下具有较高的极限承载力,适用于对负弯矩承载力要求较高的工程。

     

    Abstract: This study investigates the mechanical behavior of steel fiber-reinforced concrete (SFRC) segments with different joint configurations (bent bolts, inclined bolts, and double-layer bolts) through numerical simulation method verified by laboratory tests, focusing on bending stiffness, ultimate bearing capacity, and failure modes. The results demonstrate that SFRC joints exhibit superior ultimate bearing capacity compared to plain concrete (PC) and reinforced concrete (RC) joints, particularly under positive bending moments, while their stiffness remains comparable to PC joints but lower than RC joints during the moment-increasing phase, indicating limited influence of steel fibers on joint rigidity. Compared with single-bolt designs, the double-layer bolt configuration significantly improves both ultimate bearing capacity and joint stiffness, demonstrating 398% (bent bolts) and 225% (inclined bolts) stiffness enhancement under positive bending, along with 12%-14% ultimate capacity improvement under negative bending. While inclined-bolt joints exhibit intermediate mechanical performance appropriate for conventional applications, double-layer bolt joints provide superior ultimate bearing capacity under negative bending conditions, making them ideal for projects demanding high negative moment resistance.

     

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