Soil tests vital to protect buildings, say experts
Geology and construction experts urge builders to conduct soil tests before erecting buildings to ensure their ability to survive earthquakes, as the number of quakes increases in Myanmar.
GEOLOGY and construction experts are urging building companies to conduct soil tests before erecting buildings to ensure safety amid increasing earthquakes.
Government data show that over 60 earthquakes struck Myanmar in 2017 and about 40 the year before.
U Saw Htwe Zaw, vice chairman of the Myanmar Earthquake Committee (MEC), said that under the country’s National Building Code, construction of new buildings are not allowed unless soil tests have been conducted.
“We know that permission is not granted unless a soil test is conducted,” he told participants at the earthquake education media forum organised by the Myanmar Red Cross Society in Yangon on Tuesday.
“That rule should not be broken,” he said.
The Myanmar National Building Code was launched in 2016. It contains disaster-proof design norms for situations such as earthquakes, floods, wind storms and landslides. It also has a map of disaster-prone areas in the country.
But a participant at the forum, a teacher from Technical University and member of the Myanmar Earthquake Committee, said construction companies do not follow the soil tests requirement.
“Some construction companies are not following the rules. Before a soil test is completed, they start construction,” he said. “They assume construction can be done safely by looking at nearby old buildings. We advise systematic construction.”
Soil tests include on site tests, laboratory tests, soil and rock classifications and quake design based on soil type.
The on-site test includes a required number of bores depending on land and space, required depths, testing soil type, soil samples, sys- tematic recording and earthquake design.
If compared to total cost of construction, soil test costs constitute only 0.1 percent, so builders should obey the rules. For breaches, some have been suspended, said U Tun Naing, a teacher at Technical University and a member of the Myanmar Earthquake Committee.
“The cost is just a little, but people don’t do it. In Myanmar, builders make only five bores instead of 10,” he said.
Only when they work on a basement, do they find new soil types unexpectedly. So, they have to demolish some parts,” he added, noting that if work has to be suspended for one month because of the new finding, the cost is very high.
U Tun Naing lamented that the government does not have a strong inspection team to enforce the building code.
He noted that during the 1930 earthquake in Bago Region, some 50 people died and several structures were damaged in Yangon.
“We have to accept the possibility that it could happen again,” U Tun Naing said. “When 50 casualties at that time is converted to today’s equivalent, it will become a huge number.”
“Myanmar has different kinds of quake-causing faults,” he warned.
U Myo Thant, vice-chairman of the MEC, said that recent earthquakes are like ringing alarms.
“The main thing is, strong earthquakes are occurring. We are lucky that they are occurring in rural places where it is not crowded,” said U Myo Thant.
One of the main worries of the experts is the Sagaing fault, where strong quakes happened in 1929 and twice in 1930. The fault has remained quiet for nearly nine decades.
“Our building always shakes, even when a truck passes by, so I have never noticed recent quakes. For people like us who happen to live on such soft soil, officials from the township or organisations should advise us how to prepare,” a 50-year old woman in Thaketa said.
Among the townships in Yangon Region that have soft soil are Dagon Seikkan, Dala and Thaketa.
A 6.0 magnitude quake hit near Phyu township, Bago Region, on January 12, resulting in about 60 aftershocks, Yangon Region Department of Meteorology and Hydrology Director Daw Yi Yi Nyein said.
“Yangon has become a disasterprone city, with strong winds, unprecedented flooding and quakes,” she said. “All organisations and individuals should cooperate on preparedness. We need to know which areas and buildings are located on soft soil. We need to prepare for quakes depending on our location. Alluvial land is the most dangerous.”
The MEC is going to release a new quake hazard map in February based on the latest survey data in addition to previous data obtained by local research.
“Building without soil tests is dangerous to both present and future generations,” U Tun Naing warned.