Development of LSN-based pipe repair rate models utilising data from the 2011 Christchurch earthquakes

The Canterbury Earthquake Sequence (CES) adversely impacted built, economic and social environments. This included widespread physical damage to the water supply pipe network in Christchurch, resulting long service disruptions. transient permanent ground deformations generated by earthquakes CES caused a range of damage, particularly MW 6.2 22 February 2011 relatively less damaging 6.0 13 June event. Damage pipes both events was largely attributed liquefaction lateral spreading effects. Pipes made ductile material (e.g. PVC, HDPE) sustained lesser (and therefore lower repair rates) compared non-ductile AC, CI). In all cases, rates (number repairs per kilometre) typically increased with increasing severity. Utilising dataset Liquefaction Severity Number (LSN) maps from extensive geotechnical investigation following events, new rate prediction models for subjected effects have been derived are presented this paper. Repair data has analysed independently combination, providing two sets functions different levels uncertainty. were first grouped combination diameter (i.e. ϕ < 75 mm or ≥ mm) type non-ductile). then refined adding correction factors those types diameters sufficient sample length. Correction CI, PVC ≥75 MDPE HDPE80 <75 mm. Galvanised Iron (GI) performed poorly during earthquakes, very high other damaged network; warranted separate model be developed type. proposed can used risk assessment networks; i.e. estimate number potential future earthquakes.