SEISMIC PERFORMANCE EVALUATION AND RETROFIT FOR STRUCTURAL CONNECTIONS OF EXISTING STEEL BUILDINGS

1.对一座建于1969年的既有钢结构建筑进行了抗震性能试验评估。重点检查了角焊连接的弯矩节点和柱脚节点的强度和变形能力。基于动力加载试验得到的滞回关系，对整个建筑的地震反应和性能进行了分析评估。2.对三座80年代建成的既有钢结构建筑的抗震性能进行了试验评估。重点研究了方管柱与宽翼梁采用完全接头熔透焊连接的横隔板式弯矩节点。通过动载试验揭示了焊接缺陷的特征以及对弯矩节点变形能力的影响。3.对约束支撑式阻尼器进行了长周期地震动作用下的足尺动力试验，以评价滞回阻尼器的变形能力。试验结果表明，阻尼器对早期修建的既有高层建筑具有足够的抗震能力。4.对高层建筑采用大截面杆件组成的弯矩节点的抗震性能进行了试验研究。20世纪70年代，采用电渣焊接的组合方管柱和大跨度梁(800 mm和1000 mm)再现了弯矩连接。对梁柱组合件的变形能力进行了试验研究。

1.Seismic performance of an existing steel building constructed in 1969 was experimentally evaluated. The inspection was focused on strength and deformation capacity of moment connections and column base connections jointed by fillet welding. Based on hysteresis relations obtained from dynamic loading test, the seismic responses and performance of the overall building was analytically evaluated.2.Seismic performance of three existing steel buildings constructed in 1980s were experimentally evaluated. The research was focused on through diaphragm type moment connections composed of square tube columns and wide flange beams joined by complete joint penetration welding. Inspections on welding revealed characteristics of welding defects and the effect on deformation capacity of moment connections by dynamic loading tests.3.Full-scale dynamic tests on restrained brace type dampers subjected long-period ground motions were conducted to evaluate deformation capacity of hysteretic dampers. The test results revealed sufficient capacity of dampers to retrofit of existing tall buildings constructed in early period.4.Seismic performance of moment connections composed of large section members adopted for tall buildings was experimentally examined. Built-up Square tube columns fabricated by electro-slag welding and large depth beams (800mm and 1000mm) were used to reproduce the moment connections in 1970s. The deformation capacity of the beam-column subassemblies were experimentally investigated.