UHPC大键齿干接缝直剪性能及尺寸参数分析
Direct Shear Behavior and Dimensional Parameter Analysis of UHPC Dry Joint with Big Shear Key

DOI：

 作者 单位 潘仁胜1，2?覮，何伟伟2，程灵霄2，李传习1，2 （1. 桥梁工程安全控制教育部重点实验室，长沙理工大学，湖南 长沙 410004； 2. 长沙理工大学 土木工程学院，湖南 长沙 410004）

预制拼装UHPC桥梁的拼接接缝是该类桥梁整体受力尤其是剪切受力的关键. 为探究UHPC大键齿干接缝的直剪性能，基于ABAQUS塑性损伤模型建立了非线性有限元模型，并采用现有文献的UHPC键齿干接缝试验数据进行了模型校验. 以校验的有限元模型为基础，研究了UHPC大键齿干接缝直剪性能及剪切破坏过程，揭示了其两种主要破坏模式，即滑移破坏和直剪破坏. 同时，开展了UHPC干接缝的大键齿尺寸参数分析，考虑的参数主要包括：键齿深度、键齿倾角和侧向应力；根据计算分析结果，大键齿尺寸建议取深齿比0.15~0.25且键齿倾角小于37°较为合理. 此外，基于摩尔应力圆理论和有限元计算结果，建立了UHPC大键齿干接缝直剪承载力计算公式，经试验数据验证具有良好的适用性.

The joints in the precast segmental ultra-high performance concrete（UHPC） bridge are quite critical for the mechanical performance of this type of bridge，especially for its shear performance. Based on the Plastic Damage Model in ABAQUS，the nonlinear finite element model（FEM） was built to investigate the direct shear behavior of the UHPC dry joints with big shear keys，and this FEM was corrected and verified by the experimental data from available literature. On the basis of the verified FEM，the direct shear behavior and the failure mechanism of the UHPC dry joint with big shear keys were investigated. Two failure modes of the UHPC joint，slip failure and direct shear failure，were found in this paper. Furthermore，a parameter analysis was conducted to the big shear key in the UHPC dry joint，where the considered parameters included the depth，inclination and lateral compressive stress. According to the modeling results，the reasonable big shear key is suggested to have the height to shear height ratio of 0.15~0.25 and the inclination angle smaller than 37°. Finally，based on the Mohr’s stress circle theory and FEM results，a formula for predicting the direct shear capacity of UHPC dry joints was established. It was proved that the formula had promising availabilities by test data.