29/05/2020
*THE MENACE OF STRUCTURAL FAILURE IN BUILDINGS*
The building/construction industry, like most other industrial sectors in Nigeria is awashed with charlatans and unprofessional individuals who have little or no adherence to basic building practises and standards. These amongst other things are the main causes of the myriads of building collapse being witnessed across the country.
*THE ROLE OF PROPER PROFESSIONALISM*
There are certain fields of endeavour where negligence, sharp practises and ineptitude can have fatal and dire consequences. Such fields as Medicine, Pharmacy, Engineering and even Law all have their years of study exceeding the nominal four year duration for most other courses at the University. Even before and after graduation from the University, there are pupil internship, graduate internship, general and specialised examinations to be written before one is fully certified in such fields of endeavour as an expert/authority.
In such fields, it is important to have expertise and experience before you can be regarded as an authority in that discipline. Specifically, in the construction industry most graduates of less than five years have some expertise without much experience. Most craftsmen who have worked in the field for upward of 10-15 years (as is usually the case) mostly have limited experience without much expertise. These sets of skilled artisans usually possess the knowledge to carry out certain task(s) in limited/fixated ways, but lack both the theoretical as well as the technical know how of the reasons to so do.
*STRUCTURAL FAILURE IN BUILDING.*
The Structural Engineer is trained to design a structure to withstand the various diverse kinds of loadings applied to it to certain limit states (ultimate and serviceability limit states); with some important factors of safety applied during the design. A structure is deemed to have failed when;
▪️It is unable to provide its functions optimally (serviceability limit states failure).
▪️It collapses either partially and fully (ultimate limit states failure)
Serviceability limit states failure (malfuctionality) in structures less often has fatal consequences; although it is not completely void of fatal consequences. Examples of serviceability limit state failure include, (for a new building);
▪️ *Cracks all over the walls*
▪️ *Blocked drains*
▪️ *Noticeable deflections*
▪️ *Water leaks on the wall*
▪️ *Excessive vibrations*
Serviceability failure results in the lack of functionality of the structure as it is intended to function optimally. It can be due to negligence, ineptitude or sharp practises from the builder/contractor, architect, structural engineer or the mechanical/electrical engineers. It could also result from the client not making adequate provisions for the construction of the building.
In the case of the second kind of failure in building, (building collapse); it is the sole responsibility of the structural engineer to design a safe building with the best attendant economic value. It is not just enough for the structural engineer to design the structure to be safe and economical, to be rest assured that the structure will not fail; it is in the best interest of the client to allow the structural (design) engineer or any other competent engineer to interpret the design while supervising the construction of the structure.
*REASONS FOR BUILDING COLLAPSE.*
A few reasons for building collapse are highlighted below;
▪️ *Force majeure*
▪️ *Professional incompetence and Ineptitude.*
▪️ *Sharp practises.*
▪️ *Client's overbearing nature.*
▪️ *Substandard building materials.*
▪️ *Compromise from regulating agencies.*
▪️ *Overloading an existing structure.*
_*FORCE MAJEURE*_
Force majeure simply means 'an act of GOD', an uncontrollable situation that can incapacitate a person or a process from achieving set objectives. Examples of such situations include earthquake, flooding, gully erosion etc. These highlighted situations are all potently capable of causing building failure; sudden or gradual.
_*PROFESSIONAL INCOMPETENCE AND INEPTITUDE*_
The fate of a structure, viz-a-viz failure of such structures is determined at the design stage, the construction stage or through its (un)intended use. As earlier stated a (competent) structural engineer designs a structure to be both safe and economical. A wrongly analysed and designed structure could be a disaster in waiting as it is not guaranteed not to fail. Even so, if the structure is properly analysed and diligently designed but wrongly interpreted and constructed; it could equally be a disaster of fatal consequences. This is why a competent structural engineer (and other related professionals) must be present from the design stage of the structure through to the construction stage and even at the testing stage of the structure if a safe and economical structure is intended.
Incompetence or ineptitude is when unqualified persons take up the role of a structural engineer. Once the structure so intended is at least a storey building or more (beyond the scope of a bungalow) or in some cases bungalows to be built on very poor soil, then the structural engineer must be involved; whether the building is typical or not.
More often than not, bricklayers, masons, carpenters, even iron benders and other craftsmen do convince the clients that they are able to build the proposed structure without the input of a competent structural engineer. Most susceptible clients fall for this and end up with failed structures on their hands. Such failed structures end up being reworked by structural engineers at additional costs to the project..
_*SHARP PRACTISES*_
Integrity is important in all spheres of life and so the building/construction industry is no different. Sharp practices are mostly perpetrated by the main contractors, sub-contractors, the suppliers and pretty much anyone saddled with the responsibility of managing (especially) building materials delivery to site. When a contractor reduces the quality and the quantity of the structural elements that has been designed for, when the supplier delivers less quality and quantity of materials required/requested for, when labour force is inflated in terms of number and cost; these are few examples of sharp practises. For example, the structural engineer designs for 9 tons of reinforcement to finish a floor of the building and the contractor decides to use 6 tons pocketing a third of the money.
In some cases where the client fails to produce structural construction drawings, the contractor may decide to grossly over estimate the material requirements, greatly under utilising same and cashing out on the margin. The client may be smart enough to purchase his building materials and out source only labour contract to the contractor; such sites are often turned to some sort of rackets; and as for the client, it becomes a scenario of 'the more you look, the less you see'.
We must know and note that it is not all contractors, sub-contractors and suppliers that are dubious in nature. A lot of these professionals are men and women of proven integrity.
_*CLIENT'S DISPOSITION AND NATURE*_
The client is not exempted from the cause(s) of failure in his/her building. Culpability of the client starts from the very beginning when (s)he refuses to appoint competent professionals to manage the intended project. A wise client ‘indemnifies’ himself/herself by hunting for competent professionals in the construction industry to work on his/her project. Such client would also do well to adhere to the professional advice, guidelines and counsel laid down by such professionals especially when such are engaged as consultants on the project.
_*SUB-STANDARD BUILDING MATERIALS*_
Another major factor responsible for building collapse is the use of sub-standard building materials especially those used for the structural elements (reinforcement steel, cement and fine/coarse aggregate as well as water). All the building materials that are used to construct the structural elements have their specifications and design strength. It is this recommended specifications and design strength that the structural engineer utilizes in performing his analysis and design of the structure. Sometimes, the experienced structural engineer makes allowance for this by adopting lower values for these materials during the design process; yet, more often than not sub standard materials still end up being purchased/supplied to site. This is a veritable recipe for building collapse.
_*OVERLOADING EXISTING STRUCTURES*_
It is common practice these days to upscale existing buildings especially for their commercial value . Such up-scaled or sometimes, remodeled structures do usually command a higher commercial value. Sometimes, this is only done to redefine the façade and elevation view of such buildings. At other times; this is done to increase the building in volume and in the shear number of the available units. This can involve the demolition of structural elements by breaking and rebuilding them. When such structural elements are taken out without properly mitigating against any consequential effects through proper analysis and design, then there is the high possibility of disaster looming.
Sometimes there is the temptation to add more floors to an existing building. This is a very dangerous practice especially when the existing foundation had not been design to carry any of such additional loads. Those who do these often find out the hard way that the law of gravity (under all standard known conditions) has no exemptions on planet earth!
_*COMPROMISE OF OR FROM VARIOUS GOVERNMENT AGENCIES*_
The government through her various regulatory agencies has the exclusive responsibility of ensuring that existing laws and regulations are followed. If the government is too weak in the enforcement of the laws and regulations or compromises standards as a result of corruption and gratification, then the construction industry will remain an all comers affair where anything and everything go. To ensure that standards are maintained and that the incidence of collapsed buildings is reduced to its lowest tolerable minimum, the government's regulatory agencies saddled with these responsibilities must as a matter of compulsion up their game to the required notch(es).
In conclusion, if all the stakeholders in the construction industry take the appropriate responsibilities;
▪️ If the government regulatory agencies can be firmer and be 'uninduceable' in their dealings.
▪️If the client can lean more towards trusting the judgment of competent professionals and employing them on his/her project(s),
▪️If the design engineer can be more affordable, accessible and reliable.
▪️If the contractor, sub-contractor, suppliers can be more transparent in their dealings.
▪️If the craftsmen can refrain from taking up projects beyond their scope and scale without the supervisory role of a competent engineer.
▪️If the manufacturers, importers and miners of building materials can uphold the required standards.
▪️If the standard organisation of Nigeria and indeed elsewhere in the world can ensure that sub-standard building materials are not allowed in our markets;
then and only then would we be able to reduce to its lowest minimum this rising ill in our society termed building collapse.
*i.am.dapo.aluko*
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