超高性能混凝土预制节段梁剪切性能有限元分析

Finite Element Analysis of Shear Performance of Ultra-High Performance Concrete Precast Segmental Beams

超高性能混凝土(UHPC)因具有高强度、高耐久性而被广泛地应用到桥梁工程中,在UHPC预制节段梁中,剪力键的剪切特性因缺少相应的规范而成为大家共同关注的问题。因此,通过有限元软件ABAQUS模拟了UHPC的直剪性能,主要研究参数包括剪切面面积、侧向应力以及接缝类型,分析比较了不同工况下构件的破坏模式以及荷载位移曲线,得出了各参数对UHPC构件之间性能的影响规律。分析表明:随着剪力键剪切面面积的增加,构件的抗剪承载力明显提升;在侧向应力较小时(不高于0.3fc),随着侧向应力的增加,构件的破坏荷载近似线性增加;胶接缝构件因具有良好的整体性能而使抗剪承载力比同条件下干接缝构件的抗剪承载力高16%。此外,日本JSCE规范计算值与数值模拟试验结果吻合良好,表明日本JSCE规范剪力键的设计公式可用于预测UHPC节段接缝抗剪承载能力。

Ultra high performance concrete(UHPC) has been widely used in bridge engineering with its high strength and high durability. In precast UHPC segmental beams, the shear characteristics of shear keys have become a common concern due to the lack of corresponding specifications. Therefore, by using the finite element software ABAQUS, the direct shear performance of UHPC can be simulated, with three main research parameters included: shear area, lateral stress and joint type. An analysis and comparison have been made of the failure modes and load displacement curves of components under different working conditions, thus obtaining the influence rules of each parameter on the performance of UHPC components. The analysis shows that with the increase of the shear plane area, the shear capacity of the member is significantly improved;as the lateral stress, which is small, not higher than 0.3 fc, increases, the failure load of the component increases approximately linearly. Due to the good overall performance of the rubber joint component, the shear bearing capacity is 16%, which is higher than that of the dry joint component under the same conditions. The calculated values of the JSCE specification in Japan are in good agreement with the numerical simulation test results, which shows that the design formula of the Japanese JSCE specification shear key can predict the shear capacity of UHPC joints.