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的抗震性能进行了试验评估。重点对弯矩节点和柱基节点角焊连接的强度和变形能力进行了检测。根据动荷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价。对20世纪80年代建成的三栋既有钢结构建筑的抗震性能进行了试验评价。研究了采用全连接焊连接的方管柱与宽法兰梁的贯通膜片式弯矩连接。2 .通过动载试验对焊缝进行检测，揭示了焊接缺陷的特征及其对弯矩连接变形能力的影响。为评价滞回阻尼器在长周期地震动作用下的变形能力，对约束支撑型阻尼器进行了全尺寸动力试验。试验结果表明，阻尼器有足够的能力对早期建成的既有高层建筑进行改造。对高层建筑大截面构件弯矩连接的抗震性能进行了试验研究。70年代采用电渣焊组合方管柱和大深度梁（800mm和1000mm）再现弯矩连接。试验研究了梁柱组件的变形能力。

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.