On Monday, the Myanmar March 28 earthquake news cycle continued. This time, it was reported that the Bangkok skyscraper that collapsed during the 7.7-magnitude quake had construction irregularities and used substandard steel, according to a Thai watchdog agency.
Aftershocks from the quake that devastated Myanmar and rattled Thailand will reverberate for years. The immediate emergency has engineers scrambling, but engineers not on the ground are also contemplating possible repercussions for building locally and globally. Here are things to consider in Myanmar and Thailand, as well as California, Bangladesh, the Philippines, Kenya and other countries that live on fault lines or aren’t anywhere near them.
US (California)
Friday’s earthquake in Myanmar occurred on a continental transform fault called the Sagaing Fault, which is 62 miles wide and a fairly straight 750 miles long. California’s San Andreas Fault is the same length and runs vertically along the state.
This design makes an associated earthquake especially destructive, says Rebecca Bell, a tectonics reader at the Imperial College London.
“The straight nature means earthquakes can rupture over large areas- and the larger the area of the fault that slips the larger the earthquake. … Earthquakes on transform faults within continents can be particularly destructive as the earthquake rupture can be very shallow, causing a lot of shaking at the surface, and their continental nature means population centers can be located very close to the fault,” Bell says.
Myanmar
While Myanmar, like California, is prone to earthquakes, the actual quake isn’t the only factor when considering associated damage and a cultural understanding of such damage, says Senior Lecturer Ian Watkinson from the Department of Earth Sciences at Royal Holloway, University of London.
“During all previous magnitude 7 or larger earthquakes along the Sagaing Fault, Myanmar was relatively undeveloped, with mostly low-rise timber-framed buildings and brick-built religious monuments. But during the 20th century, there has been substantial development, especially in major cities.
“In 2012 there was a magnitude 6.8 earthquake about 120 km north of Mandalay, which affected relatively small villages and towns. Despite the moderate size of the earthquake, still there was substantial damage and 26 people died,” Watkinson says.
Friday’s quake, however, tested Myanmar’s new, modern infrastructure.
Watkinson says the most vulnerable in Myanmar include those in or near reinforced concrete structures, in or near buildings made of brick, near the banks of the Ayerwaddy River and in less accessible rural areas.
Thailand
Bangkok’s earthquake awareness among engineers may be worse than in Myanmar. A year ago, Suchatvee Suwansawat, a civil engineering professor at King Mongkut University and a former Council of Engineers Thailand president, came to lecture on the topic, but was disappointed in the level of interest locally. Suwansawat says the 30-story, under-construction building that collapsed shouldn’t have.
Most of Thailand’s buildings withstood the quake, perhaps due to its building code, updated in 2007 to include Bangkok and then again in 2009 to be more comprehensive, though it lacked detailed seismic design rules. Some engineers are calling for further upgrades and oversight.
While Bangkok doesn’t sit on an active fault, soft soil allows things built on it to shake relatively easily, says Christian Málaga-Chuquitaype, senior lecturer at the Department of Civil and Environmental Engineering, Imperial College London.
Málaga-Chuquitaype adds that developers in Thailand often use post-tensioning, slender columns and flat slab construction for tall buildings. Like a table with four legs, flat slab design dispenses with horizontal support.
“While this design has cost and architectural advantages, it performs poorly during earthquakes, often failing in a brittle and sudden (almost explosive) manner,” as evidenced in the video of the Thai building collapse, he says.
Su Su Nwal, president of the Thailand Section of the American Society of Civil Engineers, reported that many Bangkok high-rises suffered cracks and plaster falling.
Bangladesh
On the opposite side of Myanmar, Bangladesh officials considered its earthquake resilience options. Bangladesh’s Institute for Planning and Development warns that most of the nation’s cities are unprepared for earthquakes, citing widespread building code violations and poor urban planning. IPD urges 10 actions, including building retrofitting, comprehensive land-use planning, emergency shelter creation and code enforcement.
Philippines
Friday’s quake reverberated throughout Asia, including in the Philippines. In reaction to Friday’s quake, Philippine Senate President Francis Escudero on Monday called for new inspections of public and private infrastructure and buildings. The nation’s building code lacks quake-specific provisions, Escudero says. Several bills that seek to standardize and strengthen inspections have recently advanced in the Senate.
Kenya
No one seems immune, though some nations are becoming proactive.
A week ago in Kenya, updates to the nation’s circa 1968 building code went into effect. More comprehensive and less prescriptive, it better enables the use of new materials and solutions, according to the National Construction Authority. It also increases penalties for noncompliance.
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