某框架结构消能减震分析与设计

Seismic Energy Dissipation Analysis and Design of a Reinforced Concrete Frame

采用黏滞阻尼器对层间位移角不满足规范要求的某框架结构进行消能减震设计,对比分析了多遇与罕遇地震下减震结构与非减震结构的地震响应,分析结果表明:1)多遇地震下,消能减震结构的层剪力较原结构减小40%以上;层间位移角远小于规范要求,具有良好的抗震性能及减震效果。等效附加阻尼比平均值为:X向13.82%和Y向20.63%,乘以安全系数0.7后分别为9.67%和14.44%,满足附加4%阻尼比的性能目标;2)罕遇地震作用下,结构层间位移角最大值仅为1/111,满足"大震不倒"的设计要求。大量框架梁先后进入屈服,竖向构件基本未进入屈服,实现了"强柱弱梁"的屈服机制;3)多遇地震、罕遇地震下,黏滞阻尼器滞回曲线饱满,耗散了大量地震输入结构的能量,有效提高了结构的抗震性能与安全储备。

Viscous dampers were used in the energy dissipation design of a frame structure, of which the interlayer displacement angle exceeds the limitation given in corresponding codes. The seismic responses of the frame were analyzed comparatively under frequent and rare earthquakes. The results show that compared to the original structure, the interlayer shear stress of the structure with viscous damper is reduced by 40%. The interlayer displacement angle is far less than the upper limitations in the corresponding codes. The equivalent additional damping ratios in X and Y directions is 13.82% and 20.63%, respectively. Even after being multiplying by factor0.7, the results of 9.67% and 14.44% also meet the energy dissipation performance target of larger than 4%. Under rare earthquake, the maximum the interlayer displacement is 1/111, which meets the requirements of design that no collapse or destructive damage under rare earthquake. A large number of frame beams are yielded successively,while negligible yielded is found in most of the vertical components, which is in accordance with the criterion of＂strong column and weak beam＂. Under both the frequent and rare earthquakes, the hysteresis curves of the viscous dampers are plump, which indicates that the energy input by earthquake is dissipated by viscous dampers and the seismic performance and safety reservation of the structure are improved effectively.