An RC frame school building was designed with lower fortification requirements than required. It collapsed in the 2008 Ms8.0 Wenchuan earthquake. This study evaluated the building’s deficiency and practiced a retrofit design based on traditional demand-capacity method but with a displacement-based (DB) procedure, in which target capacities were obtained from the equivalent single-degree-of-freedom (ESDOF) systems defined by target mode shapes of the MDOF system, and shear demands were assessed using an R-μ-T relationship to match different capacity levels. To make the DB procedure code-conforming, the retrofitting elements (BRBs) were simplified as bi-linear elements, with the two-phase parameters corresponding to the code’s two-stage requirements. Shear distribution to the MDOF building was also determined by displacement shapes. BRBs’ stiffness demands and sizes were from the difference of the required and available shear resistances. The effectiveness of the method was validated by time history analyses. Different earthquake level simulations showed that, the method realized the design goals but did not lead to over-retrofitting; the BRBs took most of the shear demand but would not induce other unexpected failures. So the method was suitable for retrofitting similar structures.

RC框架学校建筑的设防要求低于要求。它在2008年汶川Ms8.0地震中坍塌。这项研究评估了建筑物的不足，并基于传统的需求容量方法但基于位移（DB）程序进行了改造设计，其中目标容量是从定义的等效单自由度（ESDOF）系统获得的通过MDOF系统的目标模式形状，并使用R - μ - T评估剪切需求关系以匹配不同的容量级别。为了使DB过程符合代码要求，将改装元素（BRB）简化为双线性元素，其两阶段参数对应于代码的两阶段要求。剪切分布到MDOF建筑物还取决于位移形状。BRB的刚度要求和尺寸来自所需抗剪强度和可用抗剪强度的差异。通过时间历史分析验证了该方法的有效性。不同的地震模拟表明，该方法可以达到设计目标，但不会导致过度改装。BRB承担了大部分剪切需求，但不会引发其他意外故障。因此，该方法适用于翻新类似的结构。