When earthquakes occur, it is the older buildings that often collapse first because they are not engineered to resist powerful earthquake forces. Those newer buildings, however, that look structurally sound often sustain non-structural damage that, despite appearances, can become unusable. This is what happened last week in Christchurch, resulting in many buildings that can no longer be occupied.
Last week our firm sent in an investigative team of structural engineers to assess the damage to Christchurch. As engineers, what we found was quite shocking but not unexpected: 30-50% of buildings constructed of unreinforced masonry (URM) sustained severe damage or collapsed. By comparison, the total damage in Port-au-Prince, Haiti as a result of last year’s earthquake was less from a percentage standpoint than what was experienced in downtown Christchurch last week. Several older non-ductile concrete buildings (existing structures that fail in a brittle manner under the load of an earthquake) have also been severely damaged or collapsed.
These findings provide proof that countries and cities that do not have mandatory retrofit ordinances for hazardous buildings are exposed to tremendous risk – not only in New Zealand, but everywhere else in the world.
Our team also observed that many, newer buildings experienced significant non-structural damage, which is dangerous for building inhabitants and greatly impacts functionality and business continuity.
People in cities situated in areas of high earthquake risk may have a false sense of security because they do not fully understand the intent of most building codes and equate code compliance to mean earthquake-proof. In fact, even in advanced earthquake engineering countries such as New Zealand, the US and Japan, most building codes are minimum guidelines for “life safety” only and have often proven to be inadequate for building sustainability, and at times, survivability.
Buildings must be better designed for disasters. Mandatory URM and non-ductile concrete structure retrofit ordinances must be put in place to save lives. And high-performance earthquake engineering must be practiced for sustainability of new buildings so they can support continued functionality of cities after a disaster. This must be done worldwide.
Together with my team, I have spent the past 13 months in Haiti working with the Ministry of Public Works, the United Nations and the Pan American Development Foundation assisting Haitian engineers to assess the damage to 400,000 buildings and repair 2,000 damaged houses as a USAID pilot project. The tragedy has to be experienced to be understood. Hiroshima is one of the great disasters of the twentieth century and has a firm place in our historical imaginations. The bomb killed 200,000 people. Yet, in terms of the loss of human life, Haiti’s earthquake caused even greater loss – over 230,000 lives.
The unfortunate truth is that engineers have predicted major earthquakes in Christchurch and Port-au-Prince for years. Of course, we could not say when but we knew there was a high probability of another earthquake. Little was done by the respective governments or the private sector. How distressing to realize that with proper engineering, much of the loss of life, structural damage and financial loss could have been reduced significantly.
Today, we know enough about constructing seismic-resistant buildings that allow them to withstand large earthquakes, protect their inhabitants and allow businesses to continue functioning. That said, today’s earthquake damage repair technology has also advanced so that in the next 24 months 100,000 homes in Haiti can be repaired with local materials and masons so that they are safer than before and can be reoccupied by their inhabitants, allowing them to leave the terrible conditions in the tent cities.
Preparing for disasters is not difficult. Responsible governments, the private sector and residents must act on the knowledge that these events can be anticipated and preparations must be made for their eventual occurrence, thereby saving lives and minimizing damage.
Dr. Miyamoto is President and CEO of Miyamoto International, a global earthquake and structural engineering firm.
Related Stories
| Nov 11, 2011
Streamline Design-build with BIM
How construction manager Barton Malow utilized BIM and design-build to deliver a quick turnaround for Georgia Tech’s new practice facility.
| Nov 11, 2011
AIA: Engineered Brick + Masonry for Commercial Buildings
Earn 1.0 AIA/CES learning units by studying this article and successfully completing the online exam.
| Nov 11, 2011
How Your Firm Can Win Federal + Military Projects
The civilian and military branches of the federal government are looking for innovative, smart-thinking AEC firms to design and construct their capital projects. Our sources give you the inside story.
| Nov 10, 2011
BD+C's 28th Annual Reconstruction Awards
A total of 13 projects recognized as part of BD+C's 28th Annual Reconstruction Awards.
| Nov 10, 2011
Grousbeck Center for Students & Technology opens doors
New Perkins School for the Blind Building is dedicated to innovation, interaction, and independence for students.
| Nov 10, 2011
Skanska Moss to expand and renovate Greenville-Spartanburg International Airport
The multi-phase terminal improvement program consists of an overall expansion to the airport’s footprint and major renovations to the existing airport terminal.
| Nov 10, 2011
Suffolk Construction awarded MBTA transit facility and streetscape project
The 21,000-sf project will feature construction of a cable-stayed pedestrian bridge over Ocean Avenue, an elevated plaza deck above Wonderland MBTA Station, a central plaza, and an at-grade pedestrian crossing over Revere Beach Boulevard
| Nov 10, 2011
Thornton Tomasetti’s Joseph and Choi to co-chair the Council on Tall Buildings and Urban Habitat’s Outrigger Design Working Group
Design guide will describe in detail the application of outriggers within the lateral load resisting systems of tall buildings, effects on building behavior and recommendations for design.
| Nov 9, 2011
Lincoln Center Pavilion wins national architecture and engineering award
The project team members include owner Lincoln Center for the Performing Arts, New York; design architect and interior designer of the restaurant, Diller Scofidio + Renfro, New York; executive architect, FXFOWLE, New York; and architect and interior designer of the film center, Rockwell Group, New York; structural engineer Arup (AISC Member), New York; and general contractor Turner Construction Company (AISC Member), New York.