SR105 Torsional response of house subfloor systems (2002)

NZS 3604:1999 stipulates the layout of bracing piles in a house piled foundation. This can still result in significantly non-symmetrical layouts. This paper describes a ‘pushover’ seismic analysis of the foundations of 20 conceptual buildings founded on piles and foundation walls. These included the more extreme eccentric situations that could be considered acceptable by NZS 3604:1999.

Recommendations are made for suitable provisions in NZS 3604:1999 to mitigate against torsion and on suitable design strength for lateral loads transmitted to foundation walls.

This report presents test results from lateral loading of house bearers to foundation walls connections. It also discusses a field survey and test results to examine the maximum deflections a house founded on piles can sustain before rupture of building services occur.