梁桥多级设防SMA减震装置

A multi-level performance SMA-based isolation system in girder bridges

近场地震动输入下,减隔震桥梁会发生比较大的位移和残余变形,导致落梁等严重震害。拟提出一种新型多级设防SMA减震装置,由三级SMA索与铅芯橡胶支座并联组成;随地震强度增大,各级SMA索依次张紧,满足不同性能需求;基于OpenSees和Sap2000软件,探索多级设防SMA减震装置恢复力模型和滞回模型,对比分析两种软件对多级设防SMA减震装置的模拟效果。以某一连续梁桥为例,以SMA索截面积进行参数分析,研究其多级减震效果。结果表明,该装置具有较好的自复位、限位和耗能能力,兼具多级设防的优点。

During the near-fault earthquake action,isolated bridges experience significant in-plane displacement and residual displacements,which may cause the bridge girders to unseating and even complete collapse.In this paper,a multi-level performance SMA-based isolation system was proposed.This device consists of 3-levels of SMA cables and conventional isolators,which are assembled in parallel.With the intensity of earthquake increasing,each level of SMA cables will be activated in a sequence to meet different performance requirements.Based on OpenSees and Sap2000 platforms,the lateral restoring force-displacement relationship and the hysteresis model of a specific SMA-based isolator was explored.The effectiveness of the two platforms for simulating the isolator was also investigated.Furthermore,a case study of a continuous bridge was conducted and parameter analysis about effective sectional area was conducted to testify the effectiveness of the isolation system in multi-level aseismic design.It turns out that this device has better displacement reduction,restoration,and energy dissipation capability.In addition,it has the advantages of multi-level performances,which ensures itself a bright prospect in application.