Comparison of the Seismic Performance of Conventional Moment Resisting Frames and Innovative Dissipative Replaceable Link Frames

The Dissipative Replaceable Link Frame (DRLF) is an innovative lateral load resisting system, recently developed, investigated, and further optimized in the European research projects FUSEIS, MATCH, INNOSEIS and DISSIPABLE. The system consists of two strong columns, which are rigidly interconnected by several horizontal beams, forming a vertical VIERENDEEL beam. The interconnecting beams are attached by bolted end-plate connections, making them easily detachable. These links are separated from the slab; consequently, they do not take part in the gravity load bearing function. The dissipative replaceable links being the only intended spots of inelastic action and therefore energy dissipation act as replaceable seismic fuses during a strong earthquake. After such an event, exchanging the beam links is foreseen to restore the structure to its undamaged pre-earthquake conditions quickly. Thus, the structure must possess sufficient re-centring capabilities. Recently an improvement of the initial DRLF system has been introduced within the DISSIPABLE research project: i.e. DRLF’s joined by means of strong coupling beams, forming a Coupled Dissipative Replaceable Link Frame (CDRLF). These coupling beams are not intended to dissipate energy, but instead should remain elastic, in order to provide a source of re-centring. In this paper the basic concept of the DRLF and CDRLF is introduced and demonstrated by applying it to the design of a typical low- and mid-rise office building. The case study includes also two traditional Moment Resisting Frames (MRF). A rough cost comparison is made based on steel consumption, and the seismic performance of both strategies is investigated via non-linear static analyses. In comparison to MRF’s it is shown, how the CDRLF approach is better suited for modern performance driven seismic design, focusing on reparability and cost effectiveness.