桥梁结构在近场脉冲型地震作用下可能会产生严重的塑性变形，致使结构在震后留有较大的残余变形。震后较大的残余变形会减小桥梁结构抵抗余震的能力，并且会增加震后结构加固维修的费用甚至需要将结构推倒重建。为满足桥梁结构在震后继续使用的要求，需发展能在震后快速自恢复的桥梁体系。本项目拟开发一种以形状记忆合金绞线为自复位材料的新型自复位耗能支撑；通过拟静力试验研究新型自复位耗能支撑的滞回性能及破坏机理；基于Bouc-Wen模型，建立自复位耗能支撑的恢复力模型；然后基于新型支撑稳定的耗能能力和良好的自恢复功能，提出通过附加自复位耗能支撑来实现桥梁结构震后自恢复的设计理念；同时给出附加于桥梁结构的自复位耗能支撑设计参数选取的设计方法；研究自复位耗能桥梁结构在近场脉冲型地震动作用下的抗震性能及震后恢复能力，并揭示结构地震破坏机理。本项目将扩展基于保险丝和自恢复的抗震设计理念，推动桥梁自恢复设计的发展。

Bridge structures may suffer the large plastic deformation after near-field ground motions with pulse-type that result in extensive structural damage along with the large residual deformations. The large residual displacements substantially reduce the anti-seismic capacity of bridge structures during the aftershock and increase the difficulty and cost of structural repairs after the earthquake. In order to meet the functional requirement of bridge structures after the earthquake, a resilient structure system was proposed. This project intends to develop a novel self-centering energy dissipation brace with shape memory alloy cables. The hysteretic behavior and the failure mechanism of the brace are studied by the quasi-static test. Based on Bouc-Wen model, the restoring force model of the self-centering energy dissipation brace is established. The design concept for the bridge structures with the self-centering energy dissipation brace as a resilient structure was developed based on the stable energy dissipation and excellent self-centering capacities. The design method of the design parameters of the self-centering energy dissipation brace for the bridge structure is also given. The seismic performance, failure mechanism and post-earthquake recovery capability of self-centering energy-dissipated bridge structures under near-field ground motion with pulse-type are then studied. The project will further extend the design concept of the structural fuse and the resilient structure and promote the development of the self-resetting energy-dissipated bridge structure design.