The Nigerian Institution of Structural Engineers (NIStructE) has attributed the cause of the collapsed building on Gerald Road, Ikoyi, Lagos State, on November 1, to several variations on the original design of the building that was initially planned to be six-storey, but was later increased to 21-storey.
The NIStructE’s view was contained in statement obtained on Tuesday, which was signed by the President of NIStructE, Dr. Kehinde B. Osifala.
Osifala explained: “There are clear indications of several design brief changes on the project and the engineering and management of these changes appear to have been seriously inadequate. The building that collapsed was initially designed for just six floors, and later to 12 floors, before this was further changed to Fifteen 15 floors.
“It could not yet be established the adequacy of any properly designed and documented further revision to the eventual (and tragically, final) Twenty-One (21) floors that was being implemented and which collapsed.”
He also said the preliminary investigation on the collapsed building showed that, “there are also indications that more than two structural engineering design firms worked on the project at different times.
“The preliminary investigation also revealed some evidence of structural inadequacy in the construction and that signs of some structural distress had already started to show within certain elements of the building. Some remedial measures were already being undertaken to address some of this. The method of implementation of this was not in accordance with sound structural engineering practices.”
Furthermore, Osifala explained that, “lack of proper quality control and quality assurance measures and processes during the construction was evident becoming noticeable as seen in the poor quality of concrete materials and workmanship observed during the examination of the collapse debris.
“All the above findings, which are very significant from the structural engineering point of view, need to be investigated further during the detailed investigation stage so that all factors related to the cause or causes of the collapse can be truly established and the appropriate lessons identified and implemented.
“We expect that the various committees that are being set up will have full access to much more information (such as all the structural drawings, the calculations, documents prepared and submitted for planning approval and for construction, material test results, site instructions and records, records of meetings, more eyewitness accounts, etc.”
The institute stated that a thorough and comprehensive structural integrity appraisal should be carried out on the other two buildings respectively that are on same site, in the light of the already gathered preliminary information about the noted inadequacies of the collapsed building.
Osifala advised members of the public to always engage only competent and capable registered professionals on their projects, adding that “it is extremely important that the appraisal is carried out by qualified and registered structural engineers who have the requisite experience.”
He stated that a ‘Structural Integrity Appraisal’ should not be limited to carrying out some non-destructive tests to evaluate the properties of the concrete, but should be “comprehensive and all-inclusive structural engineering evaluation of the entire structure, which is tailored to suit the full objectives of the appraisal. It is only after this that a clean bill of health can be confirmed for the building.
“The Nigerian Institution of Structural Engineers (NIStructE) maintains a register of its registered members and can be consulted on any matter of structural importance or concern,” he said.
It further stated that the institute waited this long in order to gather verifiable information and carry out physical assessment on the collapsed building before going public with its views.
“We are now in a position to make factual statements and provide guidance to the general public that will hopefully be enlightening but also reassuring that structures once well designed and implemented with the use of the appropriate professionals should remain safe throughout their service life.
“As these findings remain preliminary until the recommended comprehensive investigation is carried out, and the outcome of the various government’s and institutional panels have been determined, we and should not in any way jeopardise the outcomes of the more detailed investigations being organised by various professional and regulatory bodies, it is our view that the outcome of our preliminary investigation will give a general indication of what likely led to the unfortunate incidence,” it added.