University of Auckland Centre for Earthquake Engineering Research


Infrastructure

Recent earthquakes have shown that liquefaction and associated ground deformations are major geotechnical hazards to civil engineering infrastructure such as pipelines. In particular, sewer pipes have been damaged as a result of liquefaction-induced ground movement near waterways. The objective is to develop earthquake-resistant underground pipe system.

 
 

Performance of sewer pipes with liner during earthquakes


R Orense

Recent earthquakes, such as the 2010 Darfield and 2011 Christchurch earthquakes, have shown that liquefaction and associated ground deformations are major geotechnical hazards to civil engineering infrastructures, such as pipelines, during earthquakes. In particular, sewer pipes have been damaged in many areas in Christchurch as a result of liquefaction-induced lateral spreading near waterways and ground oscillation induced by seismic shaking. Although most of the damaged pipes in Christchurch were in sections made of asbestos cement, several segments of PVC and PE pipes were also sheared, pulled-out or compressed at various levels, and these damages affected the function of the sewer network in many places.

The aim of this research is to investigate the performance of sewer pipes equipped with liner during earthquakes. Although re-lining has been conventionally used to rehabilitate cracked/damaged portions of pipe as a means of completely trenchless form of restoration, its performance as structural retrofitting measure to earthquake-proof sewer pipes has never been established.

To achieve this objective, a three-stage research programme is being conducted:

  1. Numerical simulation of pipeline response using finite element (FE)- based software.
  2. Physical modelling through small-scale shaking table tests.
  3. Synthesis of test results by combining the results of numerical studies and model tests.

From the results obtained in these three stages, more comprehensive performance criteria will be established for the specified pipe and liner types.

 
 

The impact of vertical motion on bridges and infrastructure damage in the Canterbury earthquakes of 2010 and 2011


T Larkin, N Chouw

This study will address the particular characteristics of the motion inflicted on bridges and infrastructure from these events and ascertain the role these particular characteristics played in the resulting structural damage.

Two key components of the dynamics of these earthquakes are the near source effects and the very large vertical components of the resulting ground motion in some cases. Both of these factors place significant additional demands on infrastructure in some cases.

The study will address the significance of these factors in creating structural damage. It is likely that the effect of concurrent horizontal and vertical motion will be more than the sum of each part considered on its own.

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