Technical Services Division of the Kingston and St Andrew Municipal Corporation (KSAMC) has come under heavy demand from several major public institutions for post-earthquake assessments following Monday’s magnitude 5.6 earthquake which primarily rattled east coast parishes just three weeks after the island was hit by a 4.9-magnitude tremor.
City engineer at the KSAMC Xavier Chevannes told the Jamaica Observer that the entity is launching a wide-scale assessment to look at the full effect of the quake on structures most frequented by the public in the Kingston and St Andrew area. The assessment is expected to last two weeks after which an official report will be compiled.
According to Chevannes, the duration of the quake — which forced evacuations, knocked out power and resulted in some businesses and schools closing early — was one of the most “worrying” factors.
“Today, we went to St Joseph’s Field Hospital and we got some reports of structural damage but they are not worrying… the structural integrity of the building is still intact. We got reports from the Court of Appeal and Supreme Court, our officers are doing checks. This report is going to take some time because we are looking at major structures that house a lot of persons on a daily basis, first. So we will be looking at schools, hospitals, major gathering areas, and so forth,” he told the Observer.
“This activity itself, because of the duration of the tremor and the frequency of earthquakes, we decided to do a broad-scale approach rather than doing spearfishing as we used to do,” Chevannes said, adding that the data from the assessment will be used to improve building codes. He said fortuitously the quake hit while a training session regarding the building code, which is due for review, was under way.
“Knowing how buildings perform during seismic activity will better prepare us so we can build more sustainable buildings,” he noted.
In the meantime, the city engineer said initial assessments indicate that multi-storey structures in particular stood up to the test.
“Based on our analysis, just moments after the earthquake our officers were on the road; we noticed in most of the areas that they performed very well, which we anticipated based on the assessment they passed through before we issued the permits. The buildings were swaying which, in keeping with best standards, is what we wanted them to; to sway in order to dissipate the energy from these earthquakes,” he pointed out.
“We stood up well and the rigorous process we have been going through, moreso for the past 15 to 20 years at the KSAC, we expect that persons will adhere. We have been doing monitoring but we have a resource constraint which is seriously hampering our performance,” Chevannes said.
He said, while the earthquake was not a major one — tremors magnitude 7 and above are considered destructive — Monday’s quake, which went on for seconds, “could have caused massive destruction if we weren’t observing proper building practices”.
In the meantime, however, he said KSAMC experts have noticed some damage.
“Some were superficial, meaning that the structural members of the building were not severely affected so we are looking at façade and other stuff that were compromised. There were some structures that were constructed from in the 1940s-1950s in Kingston that were compromised and we have noticed some also that were compromised because of poor building practices,” Chevannes told the Observer.
“But all in all, most of the structures that would have gone through our rigours have stood up, but these are just initial assessments. We are still continuing our assessment to look at the full effect of this earthquake,” he said.
The KSAMC, he added, will be partnering with the engineering departments of the ministries of health and education as well as with the private sector to access updates from their structural engineers to get information on the performance of buildings and if these buildings were impacted.
Meanwhile, engineer Noel daCosta, past chair of the Building Code Committee of the Jamaica Institution of Engineers, told the Observer that while the quake was not a major one, a more powerful quake could have yielded more sobering results.
“We started working on a modern building code in 2003, we handed it over to the Government in 2009 as a gift to the Jamaican Government because it was put together by over 100 engineers and other building professionals on a voluntary basis. In 2018, they came out with a Building Act that would make the code mandatory, but making a law is one thing, enforcing is another and I think the enforcement mechanisms are not as robust as they could to be, and that is where I think some effort needs to be concentrated,” he said.
“As far as buildings that were put up before the code was promulgated, building contractors used whatever code they found convenient and some of it was merely custom and practice. Also, many of our buildings have not been designed by professionals. The buildings you see damaged after the 5.6 earthquake would have fared a lot worse if the earthquake was of more intensity. There are buildings that were not damaged today that might not withstand a magnitude 6,” the veteran engineer warned.
“We suspect that because a majority of buildings that were put up were not designed or monitored by professionals, then we have to expect that we are all at risk. Going forward we can insist that they use the code and inspect to make sure that they do,” he also stated.
Furthermore, he said attention should be paid to the integrity of the foundations on which buildings are mounted as well as the subsurface conditions.
Monday’s quake was felt islandwide with an epicentre located about 4 km (2.5 miles) west-northwest of Hope Bay, Portland, at approximately 10:57 am.
The quake which had a focal depth of 18 km disrupted proceedings at the Supreme Court in downtown Kingston and the Half-Way-Tree Criminal Court in St Andrew. The University of the West Indies, Mona in a statement issued to the media said in order to ensure the structural integrity of all buildings on the Mona Campus, the management would suspend operations for the rest of the day.
Chaotic scenes dominated roads in the Corporate Area as scores of students and workers headed home.