Paper 116-Seismic resilience of non-structural elements-practical solutions and implementation … Proposed areas of further improvement in terms of detailing and design are also identified with examples. Following this, the paper presents some of the design challenges in the current procurement and delivery model for the seismic restraint of NSEs, and the solutions adopted in some of our recent projects. The paper presents a project example of a practical implementation of the NZSEE / MBIE Technical Assessment Guidelines Part A and Section C10 in mitigating life safety hazards from NSEs. This paper looks back at the progress in the past 10 years in terms of key research findings and the updates of the design and assessment standards in New Zealand. Unsurprisingly, this leads to various issues when it comes to the procurement, cost estimate, execution of design, coordination and installation. These responsibilities, often driven by procurement, are split between the various designers (architects, structural and building services engineers), proprietary manufacturers, contractors, trades subcontractors, and increasingly a new group of seismic restraint specialists. Even though the industry is maturing, the design, documentation, coordination and construction monitoring responsibilities related to NSEs remain somewhat ambiguous. Since 2010, there has been a concentrated effort to raise awareness and to improve the design and assessment standards and guidelines in New Zealand. These major events, and more recently the 2016 Kaikoura Earthquake have confirmed the poor performance of non-structural elements (NSEs) such as non-loadbearing partition walls, suspended ceilings and suspended building services installed in existing buildings.
This suggests that the vertical strut system with free edges is vulnerable for multistory buildings located in any seismic zone due to its poor performance observed under large acceleration demands.Īlmost 10 years have passed since the 2010-2011 Canterbury Earthquake Sequence (CES). However, under sinusoidal excitation at the natural frequency of the ceiling systems, the strut system with free boundaries proved vulnerable as it slipped from the perimeter channel leading to major damage. All the ceiling systems performed well up to floor accelerations ranging from 1.4 to 1.6 g without any visible damage. Dynamic behavior and performance of these ceiling systems were evaluated to understand the effect of various boundary conditions and lateral force-resisting mechanisms at increasing intensity levels of input motion. Three different continuous plasterboard suspended ceiling systems were experimentally investigated through shake table-generated motions: (1) vertical strut ceiling system with all edges fixed, (2) vertical strut and lateral brace ceiling system with all edges free, and (3) vertical strut ceiling system with all edges free. The seismic clip also increased the deformability of the joint while it still carried reasonable amount of axial load. The results showed an improvement in the load bearing capacity of the joints under monotonic tension and compression loading. The tensile and compressive capacities of the grid joint with and without seismic clips in each failure mode were quantified and comparisons were made between the as-built and strengthened connections. Different failure mechanisms were identified in the monotonic experiments. Following these findings, the study reported herein aims at experimentally investigating the possibility of strengthening the connection between cross tees and main tees in suspended ceilings through the addition of a seismic clip.
Experimental tests of different suspended ceiling components have identified the grid connections and rivet fixtures as the weakest components. Hence, the ceiling system is only as strong as the weakest of the load path components. the main tees) to the buildings through the perimeter supports. cross tees) to the longitudinal grid members (i.e. In typical suspended ceilings, the seismic inertial force flows from the tiles to the transverse grid members (i.e. Suspended ceiling failure is frequently reported as a cause of financial loss following earthquakes.