Friday Seminar (19 August) Rajesh Dhakal (Univ. Canterbury)

Title: Beyond Life-Safety: The Quest Continues


Current versions of seismic design codes worldwide aim to achieve life-safety in severe and rare earthquakes. As a result, not many modern buildings have collapsed, and people have rarely died in such buildings even in severe earthquakes. However, current seismic design principles allow structures to be damaged even in minor-moderate shakings. Consequently, modern building stocks have suffered damage in all recent earthquakes, and the financial losses to the community arising from damage and downtime of these buildings have been unacceptably high in many earthquakes.

Following the 2010-11 Canterbury (New Zealand) earthquake sequence, New Zealand engineers (justifiably) claimed that the performance of building stock in general was better than what they were designed to achieve. This has perplexed the New Zealand public who are still struggling to cope with the huge scale of financial loss caused by this earthquake sequence. Hence, it is necessary that the seismic design objectives be revised to meet public expectations.

Observations from recent earthquakes have highlighted that the majority of seismic loss in buildings are attributable to damage of secondary components (known as non-structural elements; i.e. NSEs). Hence, enhancing seismic performance of non-structural elements (SPONSE) is a must if we want to minimize financial implications of future earthquakes. Unsurprisingly, awareness of the importance of SPONSE research has significantly increased lately, and researchers are striving to better understand the inherent weaknesses in the current NSEs’ design and installation practices and to develop low-damage solutions for key NSEs.