Revisiting The Fundamentals Of Building Collapse
Cases of building failures and collapse in Nigeria has reached an alarming and lamentable stage. It is a disaster comparable to flood disaster, earthquake and aircraft considering the magnitude of lives and property lost. Building failure is mostly observed in big cities where there are multiple numbers of houses, a typical example of which is Port-Harcourt, Lagos and Abuja.
Failure of structure is not a strange thing in the construction industry but it is never designed to happen. Incidents of collapsed buildings, collapsed bridges or other structures of various types are not peculiar to Nigeria alone. But, the continuous report of collapsed buildings in Nigeria needs to be checked urgently.
An informal survey conducted by the Nigeria Institute of Buildings (NIOB) has revealed that more buildings may have collapsed during construction in Lagos state than in the rest of the country put together over the past 45 years. There are similar cases of collapsed buildings across the country.
Buildings are structures that serve as shelters for man, his properties and activities. They must be properly planned, designed and constructed to obtain desired satisfaction from the environment. The factors to be observed in building construction include durability, adequate stability to prevent its failure or discomfort to the users, resistance to weather, fire outbreak and other forms of accidents.
Failure is an unacceptable difference between expected and observed performance. A failure can be considered as occurring in a component when that component can no longer be relied upon to fulfil its principal functions. Limited deflection in a floor that causes a certain amount of crack/distortion in partitions could reasonably be considered as defect but not a failure, whereas excessive deflection resulting in serious damage to partitions, ceilings and floor finishes could be classed as a failure.
Failure in buildings could be of two types, namely: cosmetic failure that occurs when something has been added to or subtracted from the building, thus affecting the structure’s outlook. On the other hand, structural failure affects both the outlook and structural stability of the building.
Major structural failures of buildings are currently well known in Nigeria because many are described in the print media. These failures become known to the public, because someone is killed or seriously hurt, not just to discredit the structural engineer, the builder and the other professionals involved in the case of the collapsed buildings.
The collapse of a seven-storey building in GRA, Port Harcourt on November 23 last year killing scores of persons remains one of the tragic experiences that characterizes the dangers of building collapse. The building crumbled, taking innocent lives, leaving many homeless, devastated and traumatised with so many still in shock of the incident.
Months after, precisely 14thth March 2019, a three-storey building in the Itafaji area of Lagos Island collapsed, killing school pupils and leaving so many injured. This was another tragic event as many where put into mourning and devastation.
Days after the tragic event in the Itafaji area, another building at Oko Arin, Lagos Island collapsed, although it was one of the buildings marked for demolition by the Lagos state government.
These incidences within the last six months reveals that emphasis should be placed in addressing the issue of building collapse before it causes more havoc in our society.
According to a Structural Engineer, Chinenye Douglas, causes of building failures in Nigeria are attributed as follows; 50 per cent of the causes owing to design faults, 40 per cent to fault on construction site and 10 per cent to product failure. Building failures could be as a result of defects under any or all of the stages in design approval of drawings and the supervision/construction stage. Almost all the tragic incidents recorded in Nigeria have been blamed on either the developers for failure to comply with building regulations, or professional builders, architects and engineers, as well as government agencies whose duty is to ensure compliance.
Douglas suggested that the overturning of structures owing to heavy wind loads, sliding of structures due to lateral loads are major types of failures of buildings. In addition, he categorised the following as the major causes of structural failures: environmental changes, natural and man-made hazards, improper presentation and interpretation in the design.
A building accessories dealer at the popular building materials section of the mile 3 market, Mr. Sunny Oboko lamented the use of fake/substantial products by builders as the cause of the rising cases of building collapse in Nigeria. To him, site engineers and contractors must ensure that materials used for construction purposes meet the requirements set internationally and locally.
He said, “the major cause of the building collapse lately is the use of fake materials for building. People for their selfish benefits divert resources given to them to get quality buildings materials, purchase inferior materials and then the result is what we see now. If contractors can do the right things, I believe we’re half way to solving the issue at hand.”
Those who are usually first accused of professional negligence are the architect, structural engineer, the contractor and planning authority officials. The inability of the architects and especially the structural engineer to properly carry out his own part of the work to see to the fact that the right number and sizes of reinforcements are used often times lead to collapse of buildings.
The inability of Town Planning Authorities to ensure that architectural and structural designs (and structural calculations) conform to design principles before approvals are given can also be attributed to structural failures. From past occurrences, the town planning authority that ought to enforce its development control regulations can hardly be seen to be firm in enforcing its regulations, so that the incidences of collapsed buildings are prevented or abated. Some officials of the planning authorities sometimes compromise their position and allow developers/landlords to recklessly contravene development control regulations.
Added to this dimension is the very slow pace at which the planning authorities enforce the law. During construction, the consultants and the contractors must have competent persons on site to monitor work as it progresses, failure to do so could lead to bad or poor workmanship and therefore results in structural failure. Often, developers and landlords of collapsed building try to cut corners in the use of materials for construction. They deliberately deviate from what was approved for them and begin to contravene in the process of construction.
In addressing the issue of building collapse, remedial actions need to be put in place which could be used as preventive measures. Preventive actions are those that are taken when design and construction standards are appropriately stated, adhered to and tailored by the professionals and the planning authority officials.
In order to reduce the problems of collapsed buildings to a manageable proportion, the following preventive measures are proposed:
i) Stringent penalties should be applied for those responsible for collapse of buildings, particularly when loss of lives is involved.
ii) Town Planning Authorities should be adequately staffed and equipped with professionals in the construction industry. For effective monitoring of projects during and after construction.
iii) Continuing professional development should be emphasised by both the professional bodies and the government on modern trends in the building industry. To keep members of the building industry abreast with new trends in construction.
iv) Government should provide an enabling law for the training, and effective control of artisans and craftsmen in the building industry.
v) Government should screen those getting involved in housing projects. For any structure more than a bungalow, a structural engineer must be involved.
vi) Construction work should only be carried out by registered contractors and supervised by registered architects, engineers and builders rather than engaging unskilled contractors.
vii) Clients should obtain approvals before they begin construction. At the same time, they should work with the approved drawings and specifications. Any alterations should be approved before their implementations.
viii) To promote the safety of buildings therefore, a holistic approach is required whereby all relevant outfits and organisations must be involved apart from the recognised professional bodies.
ix) A regular audit of defective structures must be carried out and such structures marked for demolition should be demolished before it causes havoc on lives and properties.
x) Government at all levels should intensify public enlightenment, placing emphasis on how building disasters could be prevented rather than managing situations which might be costlier.
The various professional bodies in the building industry have a duty to constantly educate and remind their members of the ethics of the profession. The enactment and implementation of the National Building code has no substitute, with this, construction of buildings will be effectively regulated. If the recommended preventive measures are taken seriously, then the issue of collapsed buildings in our society will be ameliorated or completely eradicated, as is the case in the developed nations.