5.3 Lessons from Recent Earthquakes
The Performance of Lifeline Utilities following the 27th February 2010 Maule Earthquake Chile
N.L. Evans & C. McGhie
ABSTRACT: In May 2010 the New Zealand Society for Earthquake Engineering sent a group of professionals to Chile following the catastrophic February 27 Maule Earthquake to identify lessons that could be learnt by New Zealand. Included in these studies was the performance of lifeline utilities following the earthquake and tsunami and how they responded to the devastation.
Modern and Historic Earth Buildings: Observations of the 4th September 2010 Darfield Earthquake
H.W. Morris, R. Walker & T. Drupsteen
ABSTRACT: The New Zealand Earth Building Standards published in 1998 are very comprehensive and gain considerable attention internationally. The Darfield earthquake is the first time that the NZ reinforcing approach has been tested in the field. Ten modern style houses using rammed earth, adobe, pressed earth brick, and poured earth technologies were surveyed. Where good reinforcement and design was applied the minor damage was due to differential ground movement, very high walls, or inadequate detailing. Four unreinforced historic, or reconstructed, cob and sod cottages were investigated including some major damage. Two cottages include earth walls from the 1860’s, for the most severely damaged it is important to preserve the original material components.
Seismic Assessment of the R/C Buildings: The Case Study of Di.Coma.C Centre After the L’Aquila (Italy) 2009 Seismic Sequence
F.C. Ponzo, A. Mossucca, A. Di Cesare, D. Nigro, M. Dolce & C. Moroni
ABSTRACT: On the 6th of April 2009 a Mw = 6.3 earthquake occurred in the region of Abruzzo situated in central Italy having an epicenter very close to the centre of the city of L’Aquila. The event produced casualties and damage to buildings, lifelines and other infrastructures. The headquarters of the post-earthquake emergency management, directed by the command and control (Di.Coma.C) task force, was established temporarily in the training academy of the Guardia di Finanza (Finance Police). This complex of structures is located 3km from the epicenter of the earthquake in the suburb of Coppito. During the first two months following the event, all the buildings in the complex were subjected to an extensive Seismic Vulnerability evaluation. The academy complex is principally composed of r/c structural buildings with the addition of some steel and precast r/c structures .This fast seismic evaluation was performed in order to assess the structural safety level of all buildings and their suitability for hosting the emergency response coordination as well as special events such as the G8 summit which took place on the 8th of July 2009. All activities were carried out in coordination with the Italian civil defense department and RELUIS (a Network of Seismic Engineering Laboratories). Several operation units (UO) coming from different Italian universities participated in the structural assessment and the general outcomes of the vulnerability assessment performed by the University of Basilicata (UNIBAS) are reported in this paper. In particular, the results of: (i) the building damage assessment, (ii) in-situ diagnostic investigations on constitutive materials, (iii) dynamic identification tests and (iv) the evaluation of the residual resistance of the structure through a simplified procedure are detailed.
Post-Earthquake Field Mission to Haiti
S.P.G. Madabhushi, K. Saito & E. Booth
ABSTRACT: The Haiti earthquake of 12th January 2010 caused extensive damage in the epicentral region in and around Port-au-Prince. The moment magnitude of this earthquake was about Mw = 7.2 and the damage caused by the earthquake was wide spread. The Earthquake Engineering Field Investigation Team (EEFIT) in the UK organised a field mission to earthquake-hit Haiti with the authors as the team members. In this paper the preliminary observations made during the field visit will be made. These observations will emphasise on the geotechnical aspects including soil liquefaction and lateral spreading that were observed in Haiti. Also, damage assessment of the port and harbour structures in the Port-Au-Prince area will be carried out to validate the information obtained from pre and post-earthquake satellite imagery. In addition attempts to validate the new technique of aerial pictometric images that were available for the Port-au-Prince area will be discussed. The paper discusses disaster preparedness and the importance of certain key infrastructure such as ports and harbours in the immediate post-earthquake period with regards to relief measures flowing into the earthquake-hit zones.
Soil Liquefaction during the 2010 Darfield and 1990 Luzon Earthquakes: A Comparative Study
R.P. Orense
ABSTRACT: Soil liquefaction and associated ground deformations caused extensive damage to residential buildings and lifeline facilities in many areas in Christchurch City (New Zealand) during the 2010 Darfield Earthquake. Twenty years earlier, the 1990 Luzon (Philippines) earthquake also caused widespread damage in Dagupan City due to liquefaction. This paper compares the liquefaction phenomenon observed in both earthquakes, with emphasis on the characteristics of the sites affected by liquefaction, the extent of ground deformations observed and the influence of liquefaction-induced settlement and lateral spreading on the built environment. In addition, the reconstruction works done in Dagupan City in the aftermath of the disaster are discussed, with emphasis on repair of tilted buildings.
Building Evaluation Processes following the Darfield Earthquake
H.J. Hare & B.D. Galloway
ABSTRACT: Following the Darfield Earthquake, a series of building evaluations were carried out of increasing depth and detail. Rapid structural assessments, following the guidelines produced by the NZSEE, were initially carried out during the State of Emergency to identify hazards to the immediate occupation of the buildings.
Following the lifting of the State of Emergency, buildings with yellow or red placards were declared dangerous and will ultimately be required to be demolished or repaired. In response to a lack of any central policy in the Building Act in this regard, the Christchurch City Council amended their Earthquake Prone Building Policy to include provisions for the repair of earthquake damaged structures to 67% of code loading.
Initial structural assessments were by necessity visual only. Detailed structural assessments involved review of the original drawings as well as intrusive investigations, with the intention of detecting underlying damage that might otherwise remain hidden. The need for such investigation has been demonstrated by some of the findings of the investigations undertaken and learnings from previous earthquakes overseas, but there is no specific policy mandating detailed assessment.
This paper addresses the different stages of structural evaluations performed following the Darfield Earthquake and provides comment on the effectiveness of policies in relation to resumption of occupancy. Recommendations for efficiencies in both the initial and detailed evaluation processes are discussed, along with recommendations for legislative and policy changes to facilitate the recovery process.