POST EARTHQUAKE FIELD INVESTIGATION OF THE MW7.6 PADANG EARTHQUAKE OF 30TH SEPTEMBER 2009

Lead Research Organisation: Newcastle University
Department Name: Civil Engineering and Geosciences

Abstract

The UK based Earthquake Engineering Field Investigation Team (EEFIT) will be conducting a reconnaissance mission to the Padang region of Sumatra, Indonesia to study the effects of the M7.6 earthquake that occurred on the 30th September 2009. The purpose of this mission is to gain insight into how buildings and infrastructure performed during this earthquake and the consequent effect on the local community. To do this a team of six people will spend approximately 1 week in the field collecting data. On their return, this data will be analysed using novel disaster management tools that will be developed as part of the project and the findings disseminated to both researchers and professional engineers. This grant application seeks financial assistance for the academic members of the EEFIT group to participate in this mission.

Planned Impact

Who will benefit from this research? Arguably the greatest disturbance to quality of life is the misery caused by natural disasters. In the case of earthquakes, the affected area is so large, the devastation caused so great and usually, although not always, the people affected so vulnerable, that even the smallest measures to reduce the impact will have an enormous effect on the quality of life of those affected. Progress in earthquake mitigation is mainly achieved by informing researchers of gaps in our earthquake engineering knowledge, informing designers of the flaws in existing design practices, informing disaster management planners and policy makers of how to ensure safer systems, and teaching local communities how they can best prepare for the next event. All will benefit from the research; however in the longer term it is the world's most vulnerable communities that will see the greatest impact. The field observations will serve as guidance to the improvement of building codes in both the affected region and to seismic zones in general. They will be particular important for informing the reconstruction process and will have a direct impact on the future resilience of the local community. An important part of EEFITs work is the training of people in both field collection techniques and practical aspects of earthquake engineering design. In Britain, there is an excellent and active earthquake engineering community; however, it can be difficult for young researchers and engineers to gain practical experience in this important discipline. The three PhD students will receive invaluable training and experience, by visiting the region, collecting data and make damage assessments, this will in turn be of great benefit to the earthquake engineering community in general. How will they benefit from this research? The research proposed in this application will provide benefits in three ways. Firstly, it will identify poor structural design and inform researchers of areas for new research needed to remedy this situation; secondly, it will inform practicing engineers of potentially unsafe structural details and, thirdly, it will assess the ability to provide infrastructure planners with a tool that will give them the potential of protecting infrastructure networks from earthquake induced landslides. This tool will also enable disaster management planners to assess not only the likelihood of landslides, but also the potential impacts of landslides resulting from earthquake events by predicting the resulting run-outs. As many of the countries that experience earthquakes are poor, it is not always possible to find the funds to divert potentially vulnerable roads; however, when complete, the VDV will enable the prioritisation of upgrades to infrastructure networks and planning for alternative ways of supplying disaster relief.

Publications

10 25 50
 
Description The key findings of this ifield investigation are

•The design and construction of schools was such that they had poor earthquake resistance and as a result, schools suffered very badly.

•The engineered buildings observed in Pariaman, although much closer to the epicentre, seemed to fare better than those in Padang (although this is difficult to say with certainty as there were far fewer of them). The reasons for this seemingly superior behaviour could have been due to either the focus of the earthquake being very deep and/or different soil conditions in the two areas resulting in significantly different characteristics of the ground shaking or differences in the quality of the design and construction of buildings in the two regions.

•In Padang, extensive damage was observed in many engineered buildings. Implementation of strong column/weak beam design philosophy has not been widely adopted in Padang and so soft storey collapse was the major failure mode observed in engineered buildings.

•There were examples of buildings that had received strong ground shaking (evidenced by the major damage to masonry infill) that had suffered little structural damage. This suggests that the latest Indonesian earthquake code, its design practices and construction, is capable of providing the guidelines for designing and constructing buildings that are seismically sufficient for an earthquake of this intensity (structurally, at least).

•There was extensive major damage to masonry infill. This is a major problem with West Sumatran (and possibly Indonesian) construction.

•It is likely that buildings are either not being designed to the code, or what is being designed is not being constructed (although this may only be true for older buildings). Building supervision and approval procedures should be revised.

•The response of lifelines was variable, with the major problems resulting from lack of electricity for 10 days, damage to the main water line, and lack of mobile phone coverage. Temporary water tanks, water storage trucks, and transportable, diesel_generator mobile phone masts were used as short_term solutions. The main Padang hospital (Dr. M. Djamil) responded well and effectively gathered its resources to treat all incoming patients from surrounding areas.

•Tsunami evacuation plans need to be revisited. The warning time for the tsunami is too long to effectively stop the evacuation response due to non tsunamigenic earthquakes and the evacuation routes may be inadequate for tsunamigenic earthquakes.

•Building foundation failures were minimal in Padang, which indicates proper foundation design for engineered buildings in general. Settlements were most significant near the coast, with continuous cracks on floor slabs of buildings and flexible road pavements. Evidences of soil liquefaction in the form of sand boil deposition and upheaval of floor slabs were observed. Lateral spreading was also seen along the coastline.

•Landslides are a major threat to this region. The landslides visited by the team can only be described as "enormous and lethal." The greatest number of deaths from this earthquake resulted from landslides and there was very little chance of survival for the residents of the houses in the paths of the landslides. Considering there is likely to be another event in the not_too_distant future, there is an urgent need to assess the risk posed by earthquake induced landslide in Western Sumatra. The devastating effect that these landslides had on the communities in Pariaman is also a very strong argument to perform hazard assessment in other regions of the world.
Exploitation Route our publications on landslide hazard assessment, could be used to inform policy on risk to communities in the region and our methodology could be used to assess landslide risk in other regions
Sectors Communities and Social Services/Policy,Construction

 
Description EEFIT EARTHQUAKE MISSION GRANT: FUNDING FOR IMPROVED RESPONSE AND DISSEMINATION
Amount £205,494 (GBP)
Funding ID EP/I01778X/1 
Organisation Engineering and Physical Sciences Research Council (EPSRC) 
Sector Public
Country United Kingdom
Start 03/2011 
End 03/2016