The seismic performance of precast portal frames typical of the industrial and commercial sector could be generally improved by providing additional mechanical devices at the beam-to-column joint. Such devices could provide an additional degree of fixity and energy dissipation in a joint generally characterized by a dry hinged connection, adopted to speed-up the construction phase. Another advantage of placing additional devices at the beam-to-column joint is the possibility to act as a fuse, concentrating the seismic damage on few sacrificial and replaceable elements. A procedure to design precast portal frames adopting additional devices is provided herein. The procedure moves from the Displacement-Based Design methodology proposed by M.J.N. Priestley, and it is applicable for both the design of new structures and the retrofit of existing ones. After the derivation of the required analytical formulations, the procedure is applied to select the additional devices for a new and an existing structural system. The validation through non-linear time history analyses allows to highlight the advantages and drawbacks of the considered devices and to prove the effectiveness of the proposed design procedure.

工业和商业部门典型的预制门式框架的抗震性能通常可以通过在梁柱接头处提供额外的机械装置来提高。这种装置可以在通常以干铰链连接为特征的接头中提供额外程度的固定和能量耗散，用于加快施工阶段。在梁柱接头处放置附加装置的另一个优点是可以充当保险丝，将地震损坏集中在少数牺牲和可更换元件上。本文提供了一种设计采用附加设备的预制门式框架的过程。该程序源自 MJN Priestley 提出的基于位移的设计方法，它适用于新结构的设计和现有结构的改造。在推导出所需的分析公式后，应用程序为新的和现有的结构系统选择附加设备。通过非线性时间历史分析的验证可以突出所考虑设备的优点和缺点，并证明所提出的设计程序的有效性。