Friday, August 12, 2016

BUILDING COLLAPSE MENACE IN NIGERIA CAUSES, CONSEQUENCIES AND PREVENTABLE MEASURES BY CHIEF ENGR.OKEY EZEMA FNSE FNICE


INTRODUCTION:
We are living in a country where the news of building collapse is no longer seen as breaking news. It is happening across the nooks and cranny of Nigeria .As soon as it happens the accusing fingers of the general public go to the Engineers.

It is a well-known fact that the building industry comprises The Client,Architects,Engineers [Structural,Electrical,Mechanical Geotechnical and Environmental], Builders and Craftsmen. All these groups play major roles in ensuring that the building projects stand the test of time.
Collapse in Buildings could be total or partial failure of one or more components of a building leading to the inability of the building to perform its principal function of safety and stability

·     BRIEF HISTORY OF BUILDING COLLAPSE IN NIGERIA FROM 2013 TO 2014:

It is alarming to hear that between January 2013 and September 2014, no fewer than 27 cases of building collapse were recorded in different parts of the country with about 173 innocent Nigerians confirmed dead and 427 others injured [Daily Trust Research.)Colossal sums of money have been lost as a result of this various cases of collapsed buildings.

A survey of building collapse within the period under review shows that 17 buildings involved are residential buildings, 6 were churches while the rest are plazas and uncompleted buildings. THE Southwest zone of the country had the highest figure; the south east had only 6 incidents while 4 cases were recorded in south south.

Only 13 cases were recorded in Northern zoneof the country. It is disheartening that despite the existence of the Development Controls of various States, nobody has been tried and jailed.by competent court. Only the Synagogue case is being handled at the law court now.The consequence is more cases of collapsed buildings as those found culpable are escaping with their nefarious activities.

Before I go ahead to discuss some of the root causes of collapsed buildings in Nigeria,may I take you down the memory lane of some latest cases in Nigeria.

The Synagogue Church buildingcollapse in Lagos .On September 12 2014, the guest house of the Synagogue Church located at Ikotun Lagos State collapsed killing about 115 people of various countries, and wounding about 131 others. On 21st October 2015, a 3-storey building located at Swamp Street Odunfa Lagos Island collapsed trapping the occupants. Plateau State has also witnessed few cases of collapsed buildingsin recent past. About three cases recorded earlier had no human casualty; however On Sunday 13th September 2015 an Islamic School Building –Abu-Naib School building collapsed killing 10 pupils and injuring many. TheL shaped on-storey building collapsed after heavy down pour while lessons were in progress without any ample warning to the occupants.

This problem of building collapse is not peculiar to Nigeria, however our case has become so frequent that all stake holders in the built environment need to come together to proffer lasting solution to curb this ugly cankerworm that is gradually eating deep into the fabrics of our society and giving us the professionals bad image in the comity of nations.

·      CAUSES OF STRUCTURAL FAILURE IN BUILDINGS:
Listed below are some of the basic causes of Structural Failure of buildings
·         Dominance of quacks in the construction industry
·         Government legislation
·         Design Error
·         Poor Construction Supervision
·         Conversion of Residential Buildings to Commercial and Religious purposes.
·         Renovation of Burnt Houses/Abandoned Structures
·         Civil Commotion, Religious Disturbances/terrorism
·         Natural Disasters.
·         Geotechnical Investigation
·         Code of practice
·         Effect of high temperature
·         Developers Interference
·         Poor Building Materials.
·         Lack of Building Maintenance culture.

DETAILED CAUSES OF BUILDING COLLAPSE.

1.    DOMINANCE OF QUACKS IN THE CONSTRUCTION INDUSTRY:
The jobs of the qualified Professionals have been hijacked by Politicians and Contractors through award of what is purely a professional job. Most times those who are entrusted with engineering and construction business have no knowledge of what to do.So long as you have connection with those at the corridors of power, you are sure of very juicy contracts. These groups execute the job so poorly because they have no professional allegiance .As a result of the high level of connection of these contractors to those at the corridor of power, even those saddled with the responsibility of supervising them are incapacitated. They end up using substandard materials in the execution of the jobs, bridge construction procedures, resulting in building collapse.

2.    GOVERNMENT LEGISLATION:
The basic requirement for approval of building plans is that planning and design should be executed by persons with the current license from COREN [The Council for the Regulation of Engineering in Nigeria.] Architects Registration Council of Nigeria, [ARCON],the Council of Registered Planners.We have seen cases where building plans of one-storey Buildings are approved without being certified, and sealed by COREN Registered Engineers due to existing Government legislation.

In some cases the buildings are completed without the building plans being submitted to the Development Control for approval. Of late we understand that the Builders have started analyzing,designing and certifying Structures for approval contrary to COREN decree. The result is collapse of buildings here and there. The existing Plateau State Urban and Regional Planning Law recommends for approval Buildings below two floors without structural calculations.This was reviewed by stake holder’s forum of all professionals in the built environment in Plateau State some years back.We understand the bill has not yet been signed into law. Recall that the four cases of collapsed buildings in Plateau State are one-storey buildings.

3.    DESIGN ERROR:
Poor analysis and design of building structures is a major reason for many collapsed buildings in Nigeria.These days’ analysis and design of concrete and steel elements are carried out by people who have no thorough knowledge of the theory behind many assumptions. These analysis are often done with some soft wares like Orion and without sound judgment, the results obtained are deceptive and dangerous.
The major objective of structural analysis is to ensure that the analysis satisfy the following

·    The Structure is safe under the worst system of loading
·    The deformation of the structure does not impair the appearance, durability and performance of the structure.
·   The dynamic response of the structure does not cause alarm or discomfort to the users
·  The structure must be economical and shall not require excessive repair due to accidental over load or bad weather condition.
·  This implies that most good designs depend on the sense of judgment based on experience of the designer. These days we witness the garbage in garbage out syndrome associated with use of computer applications.

4     POOR CONSTRUCTION SUPERVISION:
In most cases, analysis and design of a project may be ok however poor construction supervision may result in a lot of mistakes during construction. In most Federal and State Government projects, Resident Engineers are appointed to supervise the project on regular basis to ensure that the contractor carries out his contractual obligations well.Due to economic issues most Consultants are made to supervise projects once a month during which problems must have arisen that could jeopardize the durability of the structures

5. CONVERTION OF RESIDENTIAL BUILDINGS TO COMMERCIALPURPOSES:

Indiscriminate conversion of residential buildings for religious and commercial purposes is another reason for collapse of buildings.  The imposed load for residential structure is not the same as that of classroom blocks, computer centers, churches, etc. The past ten years have witnessed the proliferation of churches and computer centers. Whereas the imposed loads for residential building are1.5kn/m2, church requires imposed loads of 3km/m2according to BS6399. Hotels bars and vestibulesrequire imposed loads up to 5kn/m2.  To convert a residential building to serve any of the above purpose is tantamount to overloading the structures and this may lead to serviceability failure and eventual collapse of the structure.    

6. CONTINUATION   OF   ADANDONED   BUILDINGS:

There are cases were buildings abandoned for very long times are rehabilitated without proper material tests to verify the present state of the structure. Such buildings should be verified for overall stability, strength of the structural members, durability, fire resistance, impermeability and appearance, electrical and mechanical installation before constructions can continue.

In some cases, property owners increase the number of floors of their house without considering the suitability of the existing foundation to take additional loads.
This usually results in failure as witnessed in the Synagogue building collapse.

7. RENOVATION OF BURNT HOUSES:

Research has shown that steel can lose its ductility at temperature over 600c. It loses about 20% of its actual strength. Investigations are necessary to ascertain the extent of damage to building materials before renovation work could be carried out. This could be a potential source of failure of the structure if ignored.  {See effect of temperature on structural properties}

8. CIVIL COMMOTION /RELIGIOUS DISTURBANCES / TERRORISM:

This is another source of structural failure of buildings. During civil commotions and religious disturbances such as in Kano, Bauchi, Plateau State etc. witnessed in the country, many houses collapse due to arson and felony.  Some structures were made to collapse due to use of explosives like the Jos main market case.

In America for instance, high jacked plane at top speed crashed into the world trade center. This resulted to the collapse of the building. There are many tall buildings worldwide that should be protected against such attack. In Chicago, NO 311 South Watcher, USA, the world tallest reinforced concrete building 300m high is a case study. We have another reinforced concrete building in London, the Canary Wharf Building 245m high. All these tower buildings need to be properly protected against airplane attack as experienced in the world trade center.

9 NATURAL DISASTERS: LAND SLIDES AND EARTHQUAKES:
Landslides floods earthquakes etc. can cause buildings and other engineering infrastructures to collapse.In Zaria Terrace here in Jos some timeago, movement of the earth caused part of the road to collapse. InfarawayPhilipines, thousands of high and low rise buildings collapsed killing thousands of people due to ground shaking and extensive soil liquefaction. We thank God we hardly witness these cases of earthquake in this part of the globe.

Erosion and flood has caused the collapse of many buildings as witnessed during the 2012 floodmenace in Plateau State.Some of these mishaps can be averted by huge investment in erosion control and flood checks and ecological disaster fund.

10 GEOTECHNICAL [SUB SOIL]INVESTIGATIONS:

Most designs in this country are carried out on assumption of subsoil conditions. Most clients are unwilling to carry out the basic subsoil investigation which should guide the structural Engineer on the choice of the foundation type to be adopted. Geotechnical investigation is very necessary in the analysis and design of any storey-structure.Foundations transfer and spread the loads from the structural elements like, columns, beams walls and slab to the ground.The safe bearing capacity of the soil must not be exceeded; otherwise excessive settlement may occur resulting in damage to the building.Foundation failure affects the overall stability of the building, making it liable to slide, uplift,or overturn.

11 EFFECT OF HIGH TEMPERATURE ON STRUCTURAL ELEMENTS:
Temperature fluctuation has a lot of consequences on most construction materials like steel and concrete.Research has shown that there is deterioration in the strength and ductility properties of reinforcing steel [both mild and high yield steel] when exposed to high temperature.Both mild and high yield steel show permanent strength loss when exposed to temperature above 600deg centigrade.They lose their ductility.

During the last riot in Jos many structures were set ablaze .Most of these structures have been reconstructed without consideration to the loss of strength and ductility of the reinforcements. The iron rods recovered from such houses were used to construct other storey structures subjecting the new structure to possibility of collapse.

12 THE NIGERIAN STANDARD CODE OF PRACTICE:
The Code of Practice being used for the design of concrete and steel structures in Nigeria today is the British Standard code of practice or the Euro code.Most Countries have domesticated the Euro codes to reflect the reality of the situation in their countries.Maylasia, India, Singapor etc. have domesticated the Eurocode.Nigeria the giant of Africa should begin to think of the Nigerian Standard Code of practice that suites the Nigerian Environment. In 1973, the Nigerian Standard Organization,member of the International Organization for Standardization constituted a Technical Committee with membership from Nigerian Society of Engineers,Nigerian Institute of Building,Federal and States Ministry of works, NSO,Representatives of Universities etc.The Committee came up with Nigerian Standard Code of Practice which is essentially a set of minimum requirements for design of buildings.The code should be revised to conform to the prevailing situation worldwide with adequate integration of the Nigerian Situation and the changing nature of engineering practice.

You may shudder to hear that some professional who have refused to imbibe the culture of continued professional development are still designing with CP110, CP114 in a changing world that has moved to Euro code.

The Nigerian Society of Engineers has set up Codes and Standards Committee to draft the Nigerian Code of Practice.This is a welcome development

.As a member of the NSE Codes and Standard Committee representing Nigerian Institution of Civil Engineers,I strongly feel that this is a capital intensive assignment that should be properly funded by the Federal Government and all stake holders in the built environment, considering the anticipated benefit to the safety and durability of infrastructure in Nigeria.

13 DEVELOPERS INTERFERENCE:
We have seen cases where developers economize materials to the detriment of the quality of construction. Such projects often collapse, killing innocent people who pay exorbitant rents to occupy them.

14 LACK OF BUILDING MAINTAINANCE CULTURE:
We have poor maintenance culture in Nigeria.Most buildings are hardly maintained even when serviceability failure starts to manifest.Most of the buildings that collapsed in Lagos showed ample serviceability failure signs before ultimate collapse. The occupants were asked to relocate but could not until the buildings crumbled on them. The Lagos building Control Agency has marked about 1104 buildings as defective /illegal construction. Most of the occupants due to poverty and exorbitant rent in Lagos refused to quit and as such were trapped each time this failure occurred.

15 POOR CONSTRUCTION MATERIALS:
We need to be mindful of the type of materials we use in our construction industries.
Many of us do not know that we have different grades of cement for building industry.[Grade 32.5mpa,42.5mpa,52.5mpa]Grade 32.5mpa cement for instance is for plastering while 42.5mpa is used for block molding,concrete work while 52.5mpa is for high density work like bridge construction dams embankments retaining walls etc.Here in Nigeria anything goes.Sometimes the cement is re-bagged thereby compromising the mixing ratio and subsequently the strength.

THE WAY FORWARD:
1.  The collapse of buildings cannot be totally eradicated but can be minimized if public emotions can be played down and the press can lay more emphasis on educating the publicat large on the dangers of the collapse of buildings.
2.    Use of right materials for construction of buildings and other infrastructures.
3.    Periodic testing of building materials and concrete during construction.
4.    Employment of the right caliber of professionals and artisans in the design and construction of buildings.
5.   Ensuring that designs are checked and cross checked by the right professionals and sealed and approved before construction can commence.
6.    Produce the Nigerian Standard Code of practice for the analysis and design of building and Civil engineering Structures.
7.    Adopting preventive, corrective and condition based maintenance culture in Nigeria.
8.    Reporting cases of buildings showing signs of failure to the Nigerian Society of Engineers committee on Prevention Investigation and Failure analysis Committee. By so doing you may be saving lives.
9.    The Architects who incidentally are usually the first point of call by most clients have a civic duty to remind the clients about the need for structural, electrical and mechanical engineering designs as well as geotechnical investigation.
10. To check the activities of erring professionals, members of staff of the Town Planning Authority and individual housing developers, the legal framework should be improved upon to ensure smoother, less time-consuming and less burdensome ways to try earing professionals and quacks at the  law courts.
11. To report cases of quackery in Engineering to COREN Engineering Regulation Monitoring Inspectorates for possible prosecution by COREN tribunal for appropriate sanction.

Once this is put in place, those who flout the law can be promptly and heavily sanctioned by the judiciary if the present tempo of building collapse is to be reversed.

CONCLUSION:
Most times when a building collapses, lives are lost;it could be you, your friends or relations. Besides, properties worth millions are lost. We are duty bound to ensure that such failures are averted. Thank You.


ACKNOWLEGEMENT:
Daily Trust, Osun Defenders, R.E.Olagunju, S.C.Aremu, J.Ogundele. S.A. Oloyede, C.B. Omoogun,   O.A. Akinjare,Haruna  Ibrahim, Fidelis Mac-Leva, Mustapha Suleiman

 BY

About CHIEF ENGR.OKEY EZEMA FNSE FNICE

Engr Okey Ezema FNSE is a Civil/Structural Engineer based in Jos, Plateus State, Nigeria. He is the Managing Director of Zemas and Partners Nig Ltd a consulting Engineering firm based in Jos..
He is a Fellow of Nigerian Society of Engineers,Fellow Nigerian Institution of Civil Engineers and COREN Engineering Regulation Monitoring Inspector. He has successfully handled the Structural analysis and design of many projects in Nigerian.He has equally participated in the Construction of many Federal Government projects in Nigeria as Project Manager.
He has served as a member of national exco of Nigerian Institution of Civil Engineers for two consecutive terms. Engr Okey Ezema FNSE was listed on page 208 of Nigerian Role Models A Compendium of Distinguished Nigerians[PIFAC]. He can be reached at : okeyezema@yahoo.com

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