Yan Lei, Li Guo, Gou Xiaoying, Zhang Ping, Wang Xinyong, Jiang Yu
School of Civil Engineering, Chongqing Three Gorges University, Chongqing 404100, China.
School of Civil Engineering, Chongqing Jiaotong University, Chongqing 400060, China.
Polymers (Basel). 2022 Aug 26;14(17):3506. doi: 10.3390/polym14173506.
Focusing on the dilemma that the traditional lateral shear keys are ineffectual in limiting the displacement and repair of small-to-medium spanning highway bridges, this paper briefly describes the necessity of considering fiber-reinforced polymer concrete with the shear keys design, and studies the seismic performance of an alternative retainer that focuses on three functions of "limiting displacement", "energy consumption", and "alternative link". In order to study the anti-seismic effectiveness under the seismic loads, four alternative retainer specimens with different sizes were designed. The quasi-static tests were carried out on four specimens, respectively. The seismic damage mode of the quasi-static alternative retainer was investigated. We examined the influence of the designed parameter of the alternative retainer on the anti-seismic effectiveness of the alternative retainer. Taking a two-span simply supported girder bridge, for example, the comparison between the seismic response of the bridge with retainers and without is analyzed based on a consideration of the sliding plate rubber bearings and the test results of the new retainers. The results show that the failure mode of the new alternative retainers is a two-stage process involving the alternative links: firstly shear failure and then the overall retainer damages, which is convenient to retrofit and reinforce post-earthquake. The thickness of the web of the alternative link, as a sensitive factor, influences the bearing capacity of the new retainers, yield displacement, ultimate displacement, ductility coefficient and overall energy consumption. The height of the alternative link will merely influence the ultimate bearing capacity, and transverse replacement of the main girder with the new alternative retainers is greatly reduced compared to without retainers, and the seismic response increase in the pier is gentle.
针对传统横向剪力键在限制中小跨径公路桥梁位移和修复方面效果不佳的困境，本文简要阐述了在剪力键设计中考虑纤维增强聚合物混凝土的必要性，并研究了一种侧重于“限位”“耗能”和“替代连接”三种功能的新型挡块的抗震性能。为研究地震作用下的抗震效果，设计了4个不同尺寸的新型挡块试件，分别对4个试件进行拟静力试验，研究拟静力新型挡块的地震破坏模式，考察新型挡块设计参数对其抗震效果的影响。以一座两跨简支梁桥为例，基于滑板橡胶支座并结合新型挡块的试验结果，分析了设置挡块与未设置挡块时桥梁地震响应的对比情况。结果表明，新型挡块的破坏模式为替代连接的两阶段过程：先是剪切破坏，然后是挡块整体破坏，便于震后修复加固。替代连接腹板厚度作为敏感因素，影响新型挡块的承载力、屈服位移、极限位移、延性系数和整体耗能。替代连接高度仅影响极限承载力，与未设置挡块相比，采用新型挡块对主梁进行横向置换大幅减小，桥墩地震响应增幅平缓。
