体外预应力自复位钢筋混凝土框架抗震性能振动台试验研究

Study on the seismic performance of a 3D external prestressed self-centering reinforced concrete frame by shaking table test

体外预应力自复位框架结构(EPSCF)是一种新型结构控制抗震结构,主要结构控制技术包括铰接节点构造、提供结构抗侧刚度的体外预应力措施以及采用阻尼器的位移控制措施。在已有二维EPSCF结构基础上提出三维EPSCF结构,并进行1/3比尺三维EPSCF模型结构振动台试验研究其抗震性能,试验内容包括模型设计与制作、测点布置以及结构地震响应分析。试验结果表明:罕遇地震作用下,经过设计的EPSCF结构的加速度地震响应仅为常规设计框架的1/3~1/2,而位移地震响应能满足预设要求,罕遇地震作用下的层间位移角约为1/60、接近于常规设计框架,试验结果表明EPSCF结构具有更小的加速度响应,位移响应能得到有效控制。在地震作用下,EPSCF主体结构无损伤、残余变形很小、仅阻尼器屈服,表现出良好的免损伤、易更换的韧性结构特性。

External prestressed self-centering frame(EPSCF)is a new type of controllable seismic structure.The main techniques used in EPSCF are pure hinged joints,external prestressed tendons providing lateral stiffness of structure and displacement control technique by employing dampers.Based on the previous research of the 2 D-EPSCF,the 3 D-EPSCF was proposed and a shaking table test of a 1/3-scale 3 D-EPSCF structure model was conducted to study the seismic behavior of 3 D-EPSCF.The shaking table test included design and fabrication,arrangement of measuring points,and seismic response analysis.The experimental results showed that under the earthquake the acceleration responses of the designed EPSCF is only 1/3 to 1/2 to the conventional structure and the displacement response can meet the preset design requirement.Moreover,the inter-story angle of EPSCF is about 1/60 and near to that of a conventional reinforced concrete frame(RCF).Test results indicate that EPSCF has smaller acceleration responses compared with RCF and the displacement response can be effectively controlled.Under earthquake,no damage occurred in the main components of EPSCF,the residual deformation is small,and only the inter-story dampers yielded,that show the EPSCF has resilient structural characteristics of damage-free and convenient replacement.