Tuesday, April 7, 2020

Pesquera: “We need to find a way to identify which schools are at more risk”

By on January 10, 2020

Gov. Wanda Vázquez announced late Thursday afternoon that she has appointed structural engineer Carlos Pesquera to assist the government in the implementation of a damage risk mitigation caused by the recent earthquakes in the island’s public school structures.

“Amid the emergency caused by the various earthquakes that have shaken Puerto Rico, I have taken on the task of consulting with various experts in the areas that involve addressing this situation,” Vázquez said in a statement issued by La Fortaleza. “Engineer Pesquera has demonstrated great interest in helping Puerto Rico. We appreciate his availability in providing knowledge in the structural engineering area, in which he has doctorates degree in. His experience is of extreme necessity in making informed decisions at the moment.”

Pesquera, who spoke with Caribbean Business a day prior to being appointed to the task, had suggested that one of the first matters that should be tackled to ensure that public schools structures are safe before classes can resume is that  “we need to find the way to identify which schools are at more risk.”

Pesquera said that initial assessments should first be carried out in schools in the island’s southern region to bring calm and certainty to families with students before they can return to the classroom.

Pesquera made his comments after Vázquez declared a state of emergency following Tuesday’s 6.4-magnitude earthquake. Vázquez said that the island’s public schools would have to be inspected and certified as being safe before classes resume.

Pesquera had also met with Vázquez Wednesday night to discuss some ideas as to how the process should take place.

Some 294,000 students are enrolled in the 856 public schools across the island.

Initially, seven public-school buildings in the southern coastal town of Guánica had been reported with damages, the governor said earlier this week, adding that she had ordered the inspection of all public schools before they reopen. On Thursday, the Education Department said that preliminary some 24 public suffered damages, mainly in the southern region of the island.

Meanwhile, a change.org petition had been signed by some 3,708 people as of Thursday at 7:08 p.m. by parents of public school students, urging the government to ensure that the public school structures be inspected by structural engineers and that evidence of the same be certified.

The Education Department said in a written statement Thursday that over 50 licensed engineers would be tasked with inspecting the public schools.

Meanwhile, Pesquera said that once schools in the southern region of the island are inspected by engineers the next step he recommends is to systematically check all other public-school structures on the island, noting that this is a process that could take years.

 “So, a group of experienced engineers can assess which schools are more vulnerable if another earthquake happens and create a plan to put facilities back in use as soon as possible,” Pesquera added. “But there is always going to be a risk; you have to put into perspective that a student will be at his [or her] home or at school [during an earthquake, and] you have to determine where the student is more at risk.”

The former Transportation and Public Works (DTOP by its Spanish acronym) Secretary said that: “Once you finish the mitigation measures, then you have to design and determine if in the retrofitting you need to add more steel plates or whatever needs to be done to make the structure stronger.”

The engineer further explained that there is no structure in the world that will not be at risk of some kind of damage in the event of an earthquake.

“There is no [building] code that prevents some kind of damage,” he stressed. “The codes protect and try to prevent collapses, but the structure affected by an earthquake will show some kind of sign that an earthquake happened there. You protect lives making sure structures won’t collapse, … that there are no catastrophic events.”

Pesquera said strengthening structures can be completed pretty easily with a reasonable investment.

Furthermore, the standards established to ensure schools can resume operations do not necessarily have to be based on the current construction code, Pesquera noted. He said the process of retrofitting, or structural strengthening, of any facility, whether it is a school, housing development or building, should comply with the standards that are determined will be used.

“You don’t necessarily establish the standards based on the current [building] code; you establish them so they offer a certain amount of compliance and [the structures] are secure,” he noted. “You don’t necessarily have to rehabilitate a structure based on the current code, but you do have to strengthen it. Let’s presume the intention is that they comply with the current code, then any process to strengthen a structure to withstand an earthquake takes time.”

He explained that the process starts by analyzing documents and verifying the blueprints for each structure.

“Probably for a school facility that is relatively modern, these blueprints exist and that will help determine how the construction was carried out, in terms of what structural system was used,” he stated. “And then it’s possible that based on that analysis of the documents, you can determine that field tests have to be made to establish the concrete’s stability, to collaborate if in effect the reinforcements were placed as stated in the blueprint.”

After that initial assessment, a mathematical model is created, and along with that model, you apply the lateral load that is required in the building code to ensure the structure can withstand an earthquake or hurricane event based on its location and type of structure.

“In the end, all structural designs made to withstand hurricane-force winds and earthquakes become lateral loads, which generally is the weight of the structure, [meaning] the weight of the structure becomes a lateral load,” he said. “So, you have to verify if the lateral load can withstand these kinds of events.”

In the case of excising structures, engineers will need to determine if the structure can withstand those lateral loads, Pesquera explained. If deficiencies are found, he added, then retrofitting measures have to be completed to strengthen the structure.

The Education Department, meanwhile, published a letter in social media that “Classes in the public school system will not resume until all evaluations of the public schools are carried out in their totality.”

The letter further adds that structural engineers will make onsite inspections of the buildings. The engineers conducting the onsite inspections will certify in writing what damages were caused by the recent seismic events to help ensure the safety of the public-school community.

Education Secretary Eligio Hernández said Thursday that the Regional Education Office had started to visit schools in Ponce, Guaníca, Guayanilla, and Peñuelas. Schools in

Mayagüez, Arecibo, Humacao, Caguas, and Bayamón will be visited by the Regional Education Office staff next, according to the Education Department. Three companies staffed with structural engineers will be offering the inspections, the Education Department added. These are ROV Engineering Services, Benítez, Ramos y Asociados and E.A.S. & Associates, PSC. Contracts to these companies were awarded due to the emergency under the applicable norms and procedures after Vázquez signed an executive order declaring a state of emergency. In addition, the Infrastructure Financing Authority (AFI by its Spanish acronym) contracted Ingenium Professional Group to carry out inspections. The Public Buildings Authority (AEP by its Spanish acronym) is continuing the contracting process to complete the task of inspecting all public school structure islandwide.

“We started the visits with specialized staff in the Mayagüez region,” Hernández said. “It’s important to point out that this process will be detailed, serious and what it seeks, above anything else, is to offer security to our school communities.”

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