Stairs and Access Ramps between Floors in Multi-storey Buildings
This report, which was written by Des Bull of Holmes Consulting Group, indicates that in light of the damage sustained to stairs and access ramps in the Christchurch earthquakes a review was needed into the way these items are designed. It is clear that inadequate allowance has been made in the past for the relative movement that occurs between floors in a major earthquake.
The report noted that in both previous and current design standards the displacements that stairs must sustain in a major earthquake are under-estimated. A method of determining the required design displacements for stairs in new buildings is outlined and an approach for assessing the required displacements for retrofit of existing stairs on the basis of existing design calculations is given.
Stairs and Access Ramps Between Floors in Multi-storey Buildings (.PDF) 138 kb