REVIEW OF LITERATURE
INTRODUCTION
Our focus in this chapter is to critically examine relevant literature that would assist in explaining the research problem and furthermore recognize the efforts of scholars who had previously contributed immensely to similar research. The chapter intends to deepen the understanding of the study and close the perceived gaps.
Precisely, the chapter will be considered in three sub-headings:
Conceptual Framework
Theoretical Framework
Empirical framework
CONCEPTUAL FRAMEWORK
2.1 Building Collapse
The pursuit of shelter for all mankind and his activities has always been a paramount issue. Housing is widely ranked among the most critical factors that determine the quality of life, culture and welfare of a people. It is critical to meeting the social, cultural, economic and environmental needs of people and influences the wellbeing, health and security of both the present and future generation. Housing is therefore central to the concept of sustainable development, given its complex web of relationship with the four factors of sustainability, namely; social, economic, cultural and environmental. The question of housing is of paramount concern to governments across the globe. In Nigeria for instance, all successive governments since independence highlighted housing as a major priority. Unfortunately for over 59 years of its independence, Nigeria is still grabbling with its housing/building crises. The ever mounting crisis in the building sector of Nigeria has been in various dimensions, which range from absolute housing unit shortages, to the emergence and proliferation of the squatter settlements and slums, rising cost of housing rent and of course building collapse. The incidence of building collapse in Nigeria is reaching an epidemic proportion. Adebayo (2013) wrote: the spate of building collapse and failure has become an endemic problem that has defied all attempts at providing solutions in the recent past, these incidences have resulted in the loss of lives and properties which has also infringed permanent disabilities to many. Though building collapse is not peculiar to Nigeria, the trend in the country is becoming quite worrisome and a source of concern to stakeholders. According to Ayedun, Durodola and Akinjare (2012), the spate and frequency of occurrences have become a major source of concern, not just to the government, but all meaning Nigerians especially to the stakeholders of the building industry as the magnitude of the incidents are becoming very unprecedented. That building collapse incidence is still regularly occurring despite the fact that there have been the increasing diffusion of technical and engineering knowledge over the years have brought to question whether these stake holders have critically examined the reasons, effects and solutions for building failures and the roles they can play or the strategies they can articulate that will help to ameliorate these incidences. Buildings are structures, which serve as shelter for man, his properties and activities. When properly planned, designed and erected, it gives desired satisfaction to the client or user. Some of the factors to be considered in measuring the standard of a building include durability, adequate stability to prevent its failure or discomfort to the users, resistance to weather, fire outbreak and other forms of accidents (Ikpo, 2006). The styles of building construction are constantly changing with the introduction of new materials, change in climate and techniques in construction. Consequently, the work involved in the design and construction stages of buildings are largely that of selecting materials, components and structures that will meet the expected building standards and aesthetics on economy basis. Several codes of practice universally accepted are available for the design and construction of buildings. In 2006 the Federal Republic of Nigeria published the National Building Code which hitherto is undergoing review and in the process of being passed into law by the National Assembly of the Federal Republic of Nigeria in response to the number of cases of collapsed buildings recorded in the country. This has not yielded the desired result as most States in the country have not passed the Urban and Regional Planning Law to make the National Building Code operational in their respective States. Building code is a set of legal requirements of which the purpose is to promote good practice in the design, construction and maintenance of buildings, in the interest of health, safety and welfare of people who use the buildings. The code sets out basic requirements for design and construction of buildings which represents a code of good building practice (Obiegbu, 2006). The sophisticated nature and complexity in modern building designs introduced various lines of risks in building development process instead of eliminating or removing them. These new designs and technology associated with different types of risks could lead to building failures, abandonments outright collapses. Previous researches show that there were sharp increase in the reported cases of building collapse in Nigeria in the years 1985, 1995, 1999, and 2005, and also suggests an upward trend in the number of cases of building collapse in the year 2010. The Council of Registered Builders of Nigeria (CORBON) identified 104 incidences of building collapse based on available records in Nigeria spanning from 1974 – 2016. These observations are astonishing and most worrying. In order to tackle the cases of building collapse and the associated risks, the Nigerian government at different periods made Laws to guide the building development to curb the menace and risks associated with building collapse. Adebola, Gambo, Ankeli and Daniel (2016) carried out analysis and evaluation of the death rate involved in 47 reported cases of building collapse verified between 2000 and 2020 and over 300 deaths were recorded for Lagos, Abuja and Port Harcourt which are the three major urban centers with high rate of casualties. Ayeni and Adedeji (2015) and Babalola (2015) noted that every aspect of building planning process from the architectural design through the electrical, structural, mechanical engineering, construction and maintenance require proper supervision and quality inputs by professionals in the construction industry.
2.2 Causes Of Building Collapse In Nigeria
Many causes of building collapse have been identified by difficult scholars. Collapse according to the Dictionary of Architecture and Construction refers to mechanical failure. According to Dimuna (2010), collapse is a state of complete failure, when the structure has literally given way and most members have caved-in, crumbled or buckled; the building can no longer stand as originally built. It can be seen therefore, that collapse is very extreme state of failure. The causes of building collapse can be categorized as;
That caused by the influence of man
That due to natural forces (force majeur)
This research work gives attention to that caused by the influence of man either due to his negligence or incompetence. In a communiqué issued at the end of a two-day seminar on structural failure and building collapse in August 1996; professionals in the building industry summarized the major causes of building collapse to include the following: the attitude of the public, professional bodies and governments. The absence of soil test before construction, structural designs and details are sometimes defective, lack of proper planning, absence of co-ordination between professional bodies and town planning authorities, lack of adherence to specifications by contractors, use of unqualified and unskilled personnel, poor or bad construction practices, use of sub-standard building materials, inadequate enforcement of existing laws. Causes of building collapse as highlighted by Dimuna (2010) are as follows;
2.2.1 Deficient Structural Drawing
Building collapse when structural drawings are based on false assumptions of soil strength, they can also collapse as a result of faulty structural details. Oyewale (1992) identified design faults accounting for 50% of collapse of engineering facilities in Nigeria.
2.2.2 Absence Of Proper Supervision
Even where a structural design is not deficient, absence of proper supervision on the site by qualified personnel can lead to building failure.
2.2.3 Alteration Of Approved Drawings
During construction, many contractors either on the directive of the client or in a bid to cut corners and maximize profit, alter approved building plans without corresponding amendment to structural drawings to the detriment of the structure.
2.2.4 Building Without Approved Building Drawings
Building without approved drawings and in some cases no drawings at all, ca result in the collapse of the building more so when the drawings were not vetted by qualified professionals or relevant authorities before the buildings are erected. Without drawings, all construction is based on guess work.
2.2.5 Approval Of Technically Deficient Drawings
Town Planning authorities at times approve technically deficient drawings. This may be as a result of ignorance on the part of Town Planning personnel who vet and approved these drawings or as a result of outright corruption on their part. Money may at times change hands resulting in the approval of such drawings.
2.2.6 Illegal Alteration To Existing Buildings
Client at times, on their own, alter existing structures (buildings) beyond and above the original design without any drawings, and relevant Town Planning approval. In some instances, existing bungalows have been converted to either a storey building or two or three-storey structures without any drawings and supervision by qualified personnel. The result can be anybody’s guess.
2.2.7 Absence Of Town Planning Inspection Or Monitoring Of Sites
In some cases, Town Planning Authority staff seldom visit sites to inspect or monitor progress of approved work in sites, the result of which is documented in their forms. Unfortunately, in many cases, this inspection sis non-existent. What this means is that buildings are put up without the Authority knowing anything about details of the construction. Unfortunately, these details are only known when such buildings collapse and their element get exposed for all to see. By that time lives probably may have been lost.
2.2.8 Clients Penchant To Cut Corners
A study of collapsed buildings shows that most of them are residential buildings and owned by individuals. What this meant is that one person takes all the decisions concerning the construction; due process is not followed. Nigerian client (mostly individuals) have a penchant for cutting corners by not employing qualified personnel to produce the contract documents and supervise the building while under construction, as they want to spend minimum (not optimum) amount of money on the construction (Madu, 2005).
Even where qualified professionals are employed for design and supervision, most clients insist on having the final say on what goes on in the site to detriment of proper execution of the contract. Unfortunately, if there is any mishap on site, the client blames the consultants and the contractor. It is therefore obvious that client’s penchant to cut corners is one of the problems in the building production process.
2.2.9 Use Of Substandard Materials
Substandard material especially reinforcement rods, steel sections and cement can contribute immensely to failure of buildings. Other substandard materials can also contribute to failure of buildings. Hall (1984) posited that use of low quality materials is one of the major causes of structural failure. Aniekwu and Orie (2006) in their study, also identified low quality materials as the most important cause of failure of engineering facilities in Nigeria.
2.2.10 Inefficient Workimanship (Labour)
Inefficient and fraudulent labour input can also contribute to failure of buildings. When a contractor cannot read drawings, or where he refuses to listen to the instruction of the consultant, anything can happen. Oyewande (1992) posited that faults on construction sites accounts for (40%) of collapse of structures.
2.2.11 Use Of Acidic And Salty Water
Use of acidic and salty water, as sources from oceans and seas in cities like Lagos and PortHarcourt can affect the strength of concrete when used to effect the mix of cement, and sand and rods.
2.2.12 The Activities Of Quacks
A cursory look at the building industry in Nigeria today reveals a preponderance of individuals who are ill-equipped to carry out functions associated with construction. The industry has had more than its fair share of the activities of quacks and have nothing at stake whenever problems arise. The unsuspecting public is also at a loss differentiating the real professionals from the quacks until the real harm has been done. Today, it is not strange to find staff of Town Planning offices who are mainly Town Planners and Site Inspectors, even some Land Surveyors and Builders taking architectural commissions, and masquerading as architects and deceiving the unsuspecting public. Masons have overnight transformed to engineers and builders. This is a major problem of the building industry.
2.2.13 Clients’ Over Reliance On Contractors For Decision Making On Site
Most client rely on contractors than consultants on site. This is because most contractors are either their friends, relations of the clients, or are recommended by friends or relations. The result of this relationship is that client rely more on the contractors for decision making than on the consultants. What the clients fails to realize however, is that profit is the prime motive of most contractors and not because the contractor is saving them some cost. Then end up reducing the thickness of floor slabs and foundation and even foundation depth; sizes of reinforcement rods, head room (height) of structures, all in attempt to maximise profit to the detriment of the construction, and because most clients cannot read drawings, they are ‘taken for a ride’ by most contractors. It is only when building falls that these facts come to the surface. Even for big projects owned by corporate bodies and governments etc, the contractors seem to have special relationship with agents of the clients, some desperate contractors use blackmail and intimidation to scare away and discourage consultants from project sites.
Usually, a combination of factors are implicated in the collapse of building as list above; but the timing of the recent happenings in Lagos and PortHarcourt indicates that the nature of soil is very central to the main culprit in the collapse, as these are happening especially now in the rainy season. More attention should therefore be given to geotechnical investigation for high rise structures in areas with soil that are very suspect and the water table is high. Onitsha town is an instance of where such high rise buildings are the norm, but so far no building collapse has been reported. The reason is that the soil bearing capacity is very high in most areas of the town. Also Divid (2009) identified the following; as causes of building collapse, they are as follows;
2.2.14 Bad Design: This does not mean only errors of computation, but a failure to take into account the loads the structure will carry, erroneous theories, reliance on inaccurate data, ignorance of the effect of repeated impulsive stresses, and improper choice of material or understanding of their properties. The engineer is responsible for these failures, which are created at the drawing board.
2.2.15 Faulty Construction: This has been the most important cause of structural failures, the engineer is also at fault. Here, if inspection has been lax (i.e. not strict, severe or careful enough about work, rules or standard of behaviour). This includes the use of salty sand to make concrete, the substitution of inferior steel for specified one; bad riveting or even improper lightening torque of nuts, excessive use of the drift pin to make holes line up, bad welds, and other practices well known to the construction worker.
2.2.16 Faulty Or Failing Foundation: Even an excellently designed and constructed structure will not stand on a bad foundation. Although the structure will carry its loads, but the earth beneath may not. The living Tower of Pisa is a famous example of bad foundations, but there are many others. The St. Paul, Minnesota, sink to feet or more into soft clay, but did not collapse. The displacements due to bad foundation may alter stress distribution significantly. This was such a problem with railway bridges in America that statically determine trusses were greatly preferred, since they are not subject to this danger.
2.2.17 Extraordinary Loads: These are often natural such as repeated heavy snowfalls, or the shaking of an earthquake or the winds of a hurricane. A building that is intended to stand for some years should be able to meet these challenges. A flimsy flexible structure may void destruction in an earthquake, while a solid masonry building would be destroyed. Earthquake may cause foundation problems when moist filled land liquefies which can cause building failure.
2.2.18 Unexpected Failure Modes: These are most complex of the reasons of collapse, and we have recently has a good example. Any new type of structure is subjected to unexpected failure, until its properties are well understood. Suspension bridges seemed the answer to bridging large gaps. Everything was supported by a strong cable in tension, a reliable and understood member. However, sad experience shared that bridge deck was capable of galloping and twisting without restraint from the supporting cables. Ellet’s Bridge at Wheeling collapsed in the 1840s and the Tacoma Narrows Bridge in the 1940s from this cause.
2.2.19 Incompetence Of Contractors Or Craftsmen: This is a serious issue that can lead to building collapse even before the completion of such structure, if those in charge of the project are not capable or able to do the right thing at the right time on site, it may lead to building failure e.g. improper columns, poor erections, poor settings, poor mixing etc and as well as lack of professionalism.
2.2.20 Unapproved Plan Or Self-Help Method: Many property owner and developer deviate from plan approval in order to reduce cost of construction. And by so doing, they may not take the proper design structurally or in a wrong location, and so will not meet the standard of building code and build for their personal satisfactions which leads to collapse.
2.2.21 Corruption And Greed: Many contractors, professionals in building industry and even the government are corrupt and selfish, the contractor will minimise cost to barest minimum by buying substandard materials, so as to keep some money in their personal pocket, even though they have collected their contractor fee for the job. Some Engineers and Architects will emerge in for more contract by this, will not be able to supervise the job properly. Also the government agent that is sent to site to inspect the material that are used are also collecting bribe for their selfish interest and will not see anything wrong on site of construction.
2.2.22 Natural Disasters: Examples are earthquakes, floods, fire hazards, bomb blasts, traditional charm by enemies etc. These natural disasters cannot be stop or prevented since they are unaware and natural.
2.2.23 High Cost Of Building Materials: This is a serious issue due to poverty on the part of many developers who want to have shelter, may not be able to buy the quality material due to the high cost and persistent increase day-to-day, and by this, they will go for less quality which is harmful and leads to building failure.
2.2.24 Lack Of Maintenance: Many property owners build and are careless about the maintenance of the property, they cannot maintain the building and by these it will reduce the lifespan of the property, example are building with breaking walls, broken louvers, cracks ion walls, leakage in roof etc. All these little by little will reduce the strength of the building as one faults leads to another and at the end leads to collapse.
2.2.25 Spiritual Attack: In the Nigerian context, research also shown that charm and spiritual attack can lead to building collapse, even if the building is free from any structural defect. If there is an existing problem on land issue or people fighting on a piece of land, some may go extra mile by using charm or placing charm on the site of development or while developing the building before completion, it will collapse, and no structural fault will be trace to it.
2.3 Effects Of Building Collapse In Nigeria
It can be rightly said that any pursuit of human endeavour has its cost, but the cost being paid in the Nigerian building industry cannot be justified. Each collapse carries along with it tremendous effects that cannot be easily forgotten by any of its victims. The consequences are usually in form of economic and social implications. These includes loss of human lives, injuries, economic waste in terms of loss of properties, investments, jobs, incomes, loss of trust, dignity and exasperation of crises among the stakeholders and environmental disaster (Ede, 2010).
The quantification of the complete effects of any collapse is extremely difficult as there are so many factors involved, and these including emotional and subjective factors. Apart from the number of deaths that can often be truly identified, the rest of the effects are surrounded by so many uncertainties which make the analysis only approximate. Leaving aside the grossly quantifiable economic sums, the stress, trauma and shocks may have some far-reaching effects upon the building owner and/or employees, occupant, and others involved in one way or the other with the structure. The negative impact of such failures on the social-economic development of our economy is obvious. As many previous lives are lost, the nation looses the contribution that could have come from these victims towards the socio-economic growth of the nation. More so, this increasing rate of death from building collapse in Nigeria runs against the United Nations MDGs (Millennium Development Goals) programmes aimed at reducing the mortality rate and improving safety and life expectancy of the world population. For this, incidence of deaths during the collapse is deeply analysed in the remaining parts of this research work as to proffering solutions towards reducing it.
2.4 Building Failure
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 which causes a certain amount of cracking/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 (Roddis, 1993). Those who investigate and report on failures of engineered facilities are in a good position to identify trends leading to structural safety problems and to suggest topic for critical research to mitigate this trend (Chapman, 2000). Frequently, consultants in the office, when they visit sites, see the same mistakes being made time and time again. Many of these are indicators of lack of knowledge on the part of the people undertaking the construction. It is strange to see well-fitted houses that have associated poor construction details that results in large subsequent repair bills.
Unfortunately, many of the explanation given for these poor practices are that they are common trade practices. This leads to repetition to bad practices resulting in construction failure (Philips, 2002). 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 structures’ outlook and structural stability of the building.
In Nigeria, building failures have been attributed to the following causes: design faults (50%), faults on construction site (40%) and product failure (10%) (Oyewande, 1992). Hall (1984) ascribed faulty design, faulty execution of work and use of faulty materials as major causes of structural failures. Fredrick and James (1989) suggested that the overturning of structures due to heavy wind loads, sliding of structures due to high wind, roof uplift or sliding, and building sway due to lateral loads are major types of failures of buildings. On the other hand, Akinpelu (2002) categorized the following as major causes of structural failures; environmental changes, natural and manmade hazards, improper presentation and interpretation in the design. Richard (2002) opined that deterioration of reinforced concrete could occur as a result of: corrosion of the reinforcement caused by overloading, subsidence or basic design faults, and construction defects.
Seeley (1993) recognized three major types of maintenance in building in order to restore its defective element to an acceptable standard namely; day-to-day, cyclic, and planned maintenance.
2.5 The Various Defect In Building
Defect in building is a common failure occurring on building which no building can do without any particular type of defect. The defect in building without and response can lead to building collapse. Ghafar (2004) highlighted the following defects in building, that are commonly found in building;
2.5.1 Fungus Stain And Harmful Growth
Fungal stain or mud occur when there is moisture content in the walls. It flourishes in an environment of high humidity with lack of ventilation. Harmful growth includes creeping an ivy, plant that can grow either on walls, roof or gutter, this usually happens when dirt penetrates small opening in the walls and mortar joints creating suitable ground for seed to grow. Roots can go deep into the existing holes causing further cracks and water penetration.
2.5.2 Erosion Of Mortar Joints
The main function of a mortar joint is to even out the irregularities of individual works either stones or bricks. Causes of mortar joint erosion includes salt crystallisation, scoring actions of winds, the disintegrating effect of wall growing plant; and water penetration resulting in dampness. Decayed mortar can be forcibly remove with a mechanical disc or manually raked out using a knife or spike.
2.2.3 Peeling Paint
Peeling paint usually occurs on building facades, mainly or plastered wall columns and other areas that are exposed to excessive rain and dampness. Some building located near the sea may face a greater risk. The amount of constant wind, rain and sun received can easily turn the surface of the paint to become chalky and unclad or blistered. As is the case in many vantage building, several layers of paints have been applied onto the plastered walls over the decades. Apart from line wash, other types of paints used include emulsion, oil-based, for bituminous and oil-bound water paint. Different types of paints require different methods of removal depending on their nature.
2.5.4 Defective Plastered Rendering
Defective plastered rendering occurs mostly on the external walls, columns and ceiling. In a humid tropical climate, defective rendering are normally caused by biological attacks arising from penetration of rain, evaporation, condensation, air pollution, dehydration and thermal stress. Other causes may be the mould or harmful growth, insects, animals and traffic vibration prior to being decomposed and broken apart, deteriorating may crack due to either shrinkage or movement in the substrate.
2.5.5 Cracking Of Walls And Leaning Walls
External walls may be harmful to a building if they are structurally unsound. Vertical or diagonal cracks in the wall are common symptoms of structural instability. Such defects should be investigated promptly and the causes diagnosed; be it the foundations, weak materials and joints; or any shrinkage or thermal movements such as those of timber window frames. Diagonal cracks, usually widest at the foundations and may terminate at the corner of a building, often occurs when shallow foundations are laid on shrinkage subsoil which is drier than normal or when there is a physical uplifting action of a large trees much roots close to the walls. Common causes of leaning walls include a spreading root which forces the weight of the root down towards the walls, sagging due to soil movement, weak foundation due to the presence of dampness, shrinkable clay soil or decayed building materials and disturbance or heavy mature trees with roots expanding to the local settlement.
2.5.6 Defective Rainwater Goods
Problems associated with the defective rainwater goods includes sagging or missing caves, gutters, corrodes or broken down pipes, and lacking rainwater reads. Other problems include undersized gutters or down pipes which cause an overflow of water during heavy rain, and improper disposal of water at ground level due to inadequate painting, iron rainwater goods can rust and fracture. Lack of proper wall fixing, particularly by projecting leads ears or hugs can cause instability to the down pipes; if routine building inspection and maintenance have been neglected, rainwater goods can be easily exposed to all sorts of defects.
2.5.7 Decayed Floorboards
Widely used in many vantage building including churches, school residences and railway stations, some timber floorboards have been subjected to surface abuse and subsequently deteriorate leading to structural and public safety problems. The main causes are past attacks, careless lifting of weakened boards, by occupied electricians and plumbers, lack of natural preservatives and corroded walls.
2.5.8 Insect Or Termite Attacks
Timber can deteriorate easily if not exposed to water penetration, high moisture content and loading beyond its capacity. Insects or termite attacks pose a threat to damp and digestible timber found in water plates, the feet of rafter, bearing ends of beans and trusses, as well as timber which are place against or built into damp walling. It is unwise to ignore timber that is lined with insect or termite holes because they may in the time soften the timber and form further cracks. Affected timber can be treated by pressure spraying with insecticide or fumigant insecticidal processes.
2.5.9 Roof Defect
As roof often acts as a weather shield, it is important to treat aging roof tiles. Clay roof tiles have been widely used in the heritage building. Common defects of roof tiles includes corrosion of nails that fixe the tiles to battens and rafters, the decay of battens, and the cracking of tiles caused by harmful growth. Harmful growth poses a danger to the tiles because it may lift tiles which tend to decay or take off over the years.
2.5.10 Dampness Penetration Through Walls
Dampness penetration through walls can be a serious matter, particularly to buildings located near water sources. Not only does it deteriorate building structures, but also damages on furnishings. The main causes of dampness is water entering a building through different routes. Water penetration occurs commonly through walls exposed to prevailing wet wind or rain. With the existence of gravity, water may penetrate through capillaries or cracks between mortar joints, and bricks or blocks, before building up trap moisture behind the hand renders. Water may also drive further up the wall to emerge at a higher level. Dampness also occurs in wall due to other factors such as leaking gutters or dampness, defective drain, burst plumbing and condensation due to inadequate ventilation. Dampness may also enter a building from the grange through cracks or mortar joints in the foundation walls.
2.5.11 Unstable Foundations
Foundation are critical in distributing from roofs, walls and floors onto the earth below. They are structurally important to the permanence of a building and should thus be lacking, it is pointless investing on superficial restoration work. Most of the common problems associated with the foundation depend on the geology of the ground upon which a building stands, structural failures as well as presence and height of a water table. Additionally, inherent failures may also happen in a building in which has to cope and carry any unsettled building structure, which is unsafe to users and occupants. Unstable foundation may occur because of several reasons including shrinking clay soil penetration of dampness and water that may decay walls and foundation; presence of large trees near the building and the undertaking of excavation nearby. They may also occur due to traffic vibrations, deterioration of building materials and the increased loads, particularly with a change in a building function.
2.5.12 Poor Installation Of Air-Conditioning Units
Most heritage buildings were built without air-conditioning system. Where people have to content with warm temperatures, the need to install air-conditioning system to meet modern building requirement seems necessary. Subject to the building function, structures and the effects on building fabrics, one should consider several factors before installing air-conditioning units in buildings. The cooler as drier air produced by the air-conditioning system may causes shrinkage of building materials. There may also be a possibility of condensation either on the surface or within the structure the fabric, eventually allowing the build-up of mud. Moreover, it may be difficult installing the air-conditioners as evidences by how units were haphazardly placed on windows or the front facades of some heritage buildings. Such poor practices have greatly affected the appearance of these heritage buildings.
2.6 Causes Of Building Defect And Remedies
In any building defect, there is a cause of such defect, and as such, does have remedies. Olowoake (2006) asserted that defects are failures occurring on a mortar and they are structural failures in building. Defects are caused either as a result of mistake in design and poor supervision on site.
2.6.1 Causes Of Defect In Foundation Of a Building
The defect in foundation of building are caused as a result of the following;
Mistake in design or specification
Low quality workmanship
Poor supervision
Wear and tear
Applied forces (ground environment)
Vibration, presence of magnesium, aluminium sulphates in the soil
Gases or liquids (causing dampness, chemical attacks)
Biological agent (root, mould and fungi)
Climate or temperature
Fire
Having identified the causes of defect in foundation of building, the remedies have been suggested below;
Proper attention should be devoted into knowing the nature of the soil where the structure is to be built, right from the design stage. This will determine the type and depth of the foundation, thickness of the foundation concrete, and the types, size of the concrete materials to be used. Soil test should be carried to determine the presence and extent of magnesium and aluminium sulphates and this will dictate the type of special cement and other treatment to be used. At the design stage, special consideration should be given to the depth of the foundation located near heavy trolley traffic.
2.6.2 Causes Of Cracking Of Wall And Remedies
The identified cause of cracking of wall in building are as follows;
Movement of foundation and failures
Subsoil movement (including change in water)
Crack leaking on blocked guttering on outlet behind parapet
Gutter full of frozen snow which blocks down pipe flow than those in gutter and overflows
Big trees beside the building
Too much of imposed road
Below are the remedies to the aforementioned caused of cracking of wall in a building;
Take down and rebuild the parapet in order to add or replace a damp-proof courses if the damp-proof already check that water running off it does not run into the wall.
Repairs of defective parapet roof function
Provide additional installation
Repairs or clean outlet
Fit bigger flushing and improvement of overlap into the gutter
Proper design and effective supervision
2.7 The Effects And Problems Caused By Building Collapse
Building collapse has many effect on the economy of nations as a whole (lives and properties) and as a result, the following have been identified as the effect of building collapse;
2.7.1 Waste Of Lives
Collapse of building affect many individual lives that occupy such property at the moment, collapse of building occur in such building without any notice, therefore, individuals in the building may lose their lives if there is no quick response/intervention and attention from the people around. Also, it causes injuries on people like; broken legs, hands, waste etc that may last forever.
2.7.2 Waste Of Properties
Property worth millions of Naira has been wasted in Nigeria most especially in Lagos due to building collapse. People invest for the purpose of making profit and/or personal uses and when it collapses, it discourage investors for further investment in property. The collapsed property most time cannot be regain except such property has been insured., which most developers hardly do these days.
2.7.3 Discouragement Of Property Development
Persistent collapse has discourage many developers to invest in property development, most especially those who are new in the system. As a result of this, they may move into other investments e.g. stock and shares.
2.7.4 Scarcity Of Property
Continuous collapse of property may lead to scarcity of property in a particular area as the demand for property may go higher. Also as it discourages investors or property developers, the units of dwelling will also reduce, and this will lead to scarcity of property.
2.8 Prevention And Solution To Building Collapse
Many authors agreed that building collapse cause a lot of problems in the building industry and have so many effect on the economy of the country. Hence, the need to prevent building from collapsing requires serious attention. Stella (2010) stated that the need for a functional Building Code that is enforced against all odds has always been canvassed for at the end of the occurrence. Yet after a while the clamour dies until another one occurs.
However, the Lagos State Habitat 2011 Board is on board and is currently proposing to Lagos State Building Control Agency (LABCA), an agency that will ensure that construction professionals adhere strictly to laid down standard as part of efforts to address the problems and other issue in the state. Therefore, as part of the objectives of the board and National Institute of Architect (NIA) will work together to find some modalities in shaping the new Lagos devoid of quackery to ensure professionalism in the construction industry to preventing these unending collapse of building. Prevention of building collapse should not be limited to the efforts of the government and professionals, but the properties developers also have their vital role to play by building at the right place, the right time, using the right people and the right resources.
Adewunmi (2009) added that building collapse in Nigeria are man-made and not natural; disasters, therefore they are avoidable. Building collapse can be control if all building design are carried out by qualified professional Architect, Engineers etc and ensuring certified builders are fully involve in the construction of buildings. Considerably, more work will need to be done to encourage (or ensure) that prospective developers are enlightened on the respective roles of foremen, civil engineers, builder and architects. In addition, qualified Town Planners should always inspect and approve building plan appropriately. The federal government through COREN (Council for Regulation of Engineering in Nigeria), CORBON (Council for Regulation of Building in Nigeria) and NSE (Nigerian Society of Engineers) etc should mandate compulsory Health and Safety by certification for developers and builders. Architects should restrict their activities to preparation of drawing and verification; visits to sites and should not be involve in Jack-of-all-trade by insisting in supervision of building.
There should be mutual respect among professionals. Standard Organisation of Nigeria (SON) that is not known to many people in the industry should be mandated that standard materials are not sold in the market, while their colleagues COREN, CORBON and NSE should come up with a Nigeria Local Code of practice rather than “copy-and-paste” existing foreign base ones. In summary, if the following steps are followed, it will stand as a solution to the problem of building collapse;
2.8.1 Frequent Maintenance
Maintenance should be carried out in building periodically so as to keep the building in good condition always and enable it to have long life span
2.8.2 Approval Of Plan
Before any construction work starts, the plan approval should be the first thing so as to know if the building is rightfully designed at the right place, acceptable design and bearable load.
2.8.3 Lubrication Soil Test
This is also very important so as to know the strength of the soil if it can bear load or not and to know the rightful foundation to be used because foundation design is the strength of the building.
2.8.4 Quality Materials
Quality materials should always be used, and must be tested before usage. Cost should not be minimized to get sub-standard material. As it is dangerous to the life of the developers and the property itself, when sub-standard materials are being used.
2.8.5 Good Design
The design must be given to the professional e.g. the Plan drawing to the Architect, while the structural, electrical and mechanical drawing should be done by the Engineers. And the drawing should have good drainage and ventilation so as to enable the building to have good strength, durability and stability.
2.8.6 Involvement Of Professionals
At all level from conception to the delivery stage, professionals of all kinds should be involve in all aspect of the project for perfection, and professional touch and advice.
2.9 Why Building Are Collapsing In Nigeria
Structural collapse occurs all over the world, but the rate of occurrence in Nigeria is beyond bound. The causes of building collapse in Nigeria can be traced to abnormal factors not obtainable in many other developing nations. Apart from the generally known causes of collapse such as design flaws, ageing, material fatigue, extreme operational and environmental conditions, accidents, terrorist attacks and natural hazards, the Nigerian factor becomes a prominent issue to contend with (Ede, 2010).
The Nigerian factor in the building industry nears up to its ugly head in different forms such as corruption, lawlessness and our presumptions that any engineer or professional in the built environment can assume all forms of responsibility in a building process without the basic skill required for it. Corruption is made manifest in greed and tendency to cheat in virtually every aspect, starting from poor materials and quality of work to the quantities we adopt. As disobedience to civil Laws is common in Nigeria, the case in the building industry cannot be different. For this, lawlessness finds a fertile ground in our non-adherence to the building codes and hasty construction. The use of unskilled labour, inexperienced professionals, tendency of some professionals to cross-carpet to lucrative specialist duties where they lack the skill, ignorance and the abundance of quacks in the building industry are all fact to contend with. Excessive rainfalls and poor drainage systems pose a serious problem to structures along the Nigerian coastlines. It is a common sight to see sinking old building around Lagos and within the coastal areas due to water related problems and deficient foundations, yet not all the stakeholders pay adequate attention to this problem as man y new structures manifest the same problem while the structures are still under construction. In fact, most of the collapses verified in the recent years occurred during construction stage. Issues of unregistered engineers and other professionals operating in the field are very rampant.
Even people without formal training in any of the trades needed in the construction industry often sneak themselves into the system to perform important tasks. In 2006, the Council for the Regulation of Engineering in Nigeria (COREN) recommended the prosecution of a pharmacist who supervised a collapsed building in Port-Harcourt in 2005 (Olajumoke et al, 2009). If all these issues are put under control, then the adverse effects to which our citizens are subjected to will be drastically reduced and we will have more time and resources available to confront other problems and the unpredictable consequences of the global warming which has come to stay with us.
Most of the facts highlighted above were confirmed by one of the most recent collapse verified in Abuja. On the 11th of August 2010, thirteen people died in a building, which collapsed at Ikole Street, Abuja, while about 35 persons are believed to be trapped in the debris while 10 persons were rescued (Bukola, 2010). This was the third collapse case in the city since the beginning of the year. The three-storey building, a hotel, has been under construction since 2001 and was later marked for demolition by the Federal Capital Development Authority (FCDA) because the owner added an extra floor thereby making it a four-storey building as against the specified three-storey building. When the agency discovered this, the developer was issued a “stop work” on the 12th December 2009.
The agency enforced the mechanical removal of the additional floor and subjected the entire structure to Schmidt Hammer and Structural Integrity Tests on the 29th July 2010 and the structure failed the tests. All the occupants were asked to move out of the building while legal backing for the demolition was sought but never obtained till the collapse. As some people illegally made the uncompleted structure their sleeping place at night, they became the victims of the collapse. The causes of the deaths verified in this collapse include among other things greed (the owner had the courage to seek redress from court against the demolition), non compliance with building rules and regulations, disturbance of the structural equilibrium during the removal of the illegal fourth floor, exposure of construction materials to deterioration (due to infiltration of water and steel corrosion over the past 9 years in which the structure was under construction) low quality materials, use of quacks and unskilled personnel, disobedience and poverty. Despite all the forewarnings and the efforts made by the agency, many deaths still occurred in the building.
2.10 The Basis Of Obtaining Robust Structures
Every built structure is expected to satisfy the functional objectives of safety, serviceability and economy. The processes of construction are complex and require the services of trained professionals. A high level of skill is needed both in designing and construction (Ayininuola and Olabisi, 2004). The tools to enable the professionals to realize these objectives are their professional knowledge and experiences in the different specialized fields involved in the process, available research materials, government regulations and codes. Activities necessary for the realization of efficient structures take place in the following fundamental stages: conceptual and design stage, construction-supervision stage and post construction/service stage. Every part of these stages is extremely important in the life of the structure as a mistake in any stage can have a far reaching effect in the whole building processes. The conception phase is the planning and feasibility studies stages in which some professionals (e.g. Architects, Engineers, Project managers, etc) may assist the owner to evaluate the technical options Available for the realization and advice on the feasible choice. The design phase involves more of technical preparations of the project, where the architect designs the aesthetic form of the structure while engineers design the structural frames, proportion the sizes and choose the materials compatible with the form and the environment. The basic requirements of safety, aesthetic, economy and constructability must be put into consideration during the design process (Davison and Owens, 2003). The activities of this stage will be completed with the estimation of the resources needed for the execution and the approval by the authorizing agency of the government. The construction supervision stage involves numerous and often conflicting activities, such that only trained professionals can handle them. This is the physical construction and over-seeing of the structure designed in the previous stage and every effort is made to ensure compliance of the quality with design and specification. At the completion of the construction work, a certificate of fitness for use is issued to the client to authorize the usage of the structure. The post construction-service stage is the stage in which the facility serves the purpose for which it was built without causing any form of discomfort to the user. The usage must be in conformity with the purpose of its design and any variation of usage must be authorized by the competent professionals. The structure must be continually maintained in a good state as to perform its functions for which it was built.
2.11 Component Of a Building Structure
2.11.1 Foundations
Whatever the type of structure, the qualities of the subsoil must be investigated and the design and construction made to absorb stresses from the super-structure. Causes of foundation failure include: faulty or no soil investigation, wrong choice and or design of suitable foundation; use of structure for purpose other than or total settlement of sub-structure accompanied by excessive cracking of ground floor slab, sinking of column footing, that is, punching shear failure.
2.11.2 Columns
Columns are usually struts and therefore very strong element of the structure. They hardly foil. Causes of column failure are attributed to most due to the use of structure for purpose other than originally intended for instance office blocks being used for storage e.g. books, machinery and heavy point loads for instance bank safes, etc, use of small or highly spaced columns stirrups; Excessive slander columns leading to building; use of poor quality materials. The danger signals are column crushing and spalling and splitting of concrete.
2.11.3 Beams
Beams are most susceptible to all kinds of stress than other structural elements. Such stresses include that due to bending, shear and torsion. Other failure includes deflection, bond and anchorage. Causes of collapse may be due to faulty design, use of structure for purposes other than designed, poor construction methods leading to displacement of stirrups during vibration. The symptoms depend on the type of failure viz; bending, shear, torsion, deflection
Building: Vertical cracks mostly rear middle of beam length
Shear: Inclined cracks (45o) mostly at the end of the beam. Shear failure very sudden
Torsion: Combination of horizontal and inclined cracks
2.11.4 Slabs
Causes of failure in slab are as a result of: Excessive loading especially with partition walls; reinforcements placed in the wrong position especially due to inadequate cleaning up; omission of top reinforcement at beam positions and slab ends; excessive spans, that it span or effective depth ratio; lack of adequate cover to reinforcements, and poor quality of materials and inadequate mixes,. The common symptoms include; slab vibrates when in use; cracklings especially at positions where top reinforcements are needed; rusting of bottom reinforcements and concrete spalling.
2.11.5 Cantilevers
Cantilevers are structural elements that fail most in buildings and in fact should be avoided if it is possible. However, Architects seem to like them and so the structural engineers are stuck with designing them. The causes of cantilever failure can be attributed to: displacement or displacement of the top reinforcements during construction; Insufficient bond or anchorage lengths especially in discontinuous slabs; In roof gutters, columns reinforcement not anchored into the roof beam; excessive length or effective depth ratios. Cantilever failures often occur suddenly and without warning as all three stresses-bending, shear and torsion occur simultaneously and at the same point.
However, most often cracks form at positions of maximum stress, visible defection coupled with cracking of the walls above the cantilever (Dimuna, 2010).
2.12 Consequences Of Building Collapse
The incidents of building collapse witnessed in the country in the recent years has resulted in the loss of many lives and the destruction of properties worth several millions of naira. Many families have been traumatized and many developers have lost their life investments (Dimuna, 2010). From table 1, it can be inferred that between 1975 to 1995, about 26 incidents; which claimed about 226 lives were recorded in Nigeria. Table 2 reveals that between 1982-1996, Lagos State alone recorded about 14 incidents and about 64 dead. While in a period of two years (2004-2006) as reflected in table 3 about 10 incidents were reported which claimed the lives of about 243 people. In all the cases, many people were injured and some permanently disabled.
2.13 Theoretical Framework
The links between construction management (CM), and for that matter construction economics (CE) and theory, are not strong (see de Valence 2011). This may be one of the reasons why they have not gained complete acceptance as academic disciplines and are not seen as distinct branches of management and economics respectively. Another reason may be that products and production (the focus of management and economic theories respectively) are not the same as projects and project management in general, and construction projects and CM in particular. So, are management theories of production product-based or process-based? The emphasis seems to be mainly on the range of methods and techniques available to improve the efficiency with which products are delivered, although many of these products are management decisions or plans. Processes are secondary, because they are bundled with the production decision, and despite the appearance of diversity in the range of management theories, the approach taken typically treats the firm as a ‘black box’ that turns inputs into outputs using a range of capabilities (Porter 1980). These then are a productbased set of theories. There are a number of economic concepts involved in production theory. The important ones include returns to scale, price elasticity of demand, elasticity of substitution between input factors, and technological change. Technological change has the three aspects of rate of technical change, acceleration of technical change over time, and the rate of change of marginal products (of factors). These economic effects come from the underlying production process, or processes, that firms choose between when making production decisions. The economic theory of production focuses on the input demand and output supply functions under a technical constraint that describes a range of production processes available to a firm. In that case, could production theory be relevant to CM, because the delivery of a new building or construction project is clearly about producing something. A relationship between CM and the economic theory of production is plausible because both are concerned with technology choices. However, production theory is complex. The economic theory of production developed out of the classical concern with marginal productivities into a production function focused on substitutability of factors under a technological constraint. Can CM be reinterpreted in these terms? Would that improve industry performance? Can a theory be founded on the characteristics of the industry? A new book from Milan Radosavljevic and John Bennett takes on these questions. Construction Management Strategies: A theory of construction management (2012) attempts to provide that foundation by proposing a theory of construction management which identifies the actions which help construction projects and companies to be efficient. It takes on the challenge of creating a precise, tightly defined model of construction management (CM), using five clearly differentiated methods for the delivery of building and construction projects. It is an ambitious and intellectually bold attempt to introduce new thinking into the field. de Valence G (2012) ‘A theory of construction management?’, Australasian Journal of Construction Economics and Building, 12 (3) 95-100 96 What they don’t do is draw on any of the many theories of management or production available. On one hand this seems to be an extreme case of exceptionalism - that construction is different from all other industries - school of thought. In their defence, on the other hand, Radosavljevic and Bennett argue that construction is different, because it is complex: projects have a number of interacting teams where outcomes in the future depend on the number of involved teams, the quality of relationships between interacting teams and their performance variability. In addition there is also unpredictable interference which may arise from numerous external factors (p. 77).
2.14 EMPIRICAL REVIEW
Olambe and Jinadu(2017) examines contemporary issues in building collapse and its implications for sustainable development in Nigeria. It explores whether the approach to construction by industry stakeholders is in line with the principles of sustainable development following the spate of building collapses in Nigeria. The rationale for the investigation stems from the view by scholars that construction industry stakeholders’ do not seem to consider the future in their current activities. The study establishes that the approach to construction by industry stakeholders do not match sustainable principles, and contributes to general under perforxmance of buildings. The paper recommends an overhaul of planning and implementation policies for building development regulations (e.g., building codes). The Nigerian government, as a major construction stakeholder should initiate sustainable construction measures and enforce this as best practice for the construction industry.
Comforta and Blissfulness(2016) investigate the factors influencing the use of substandard construction materials for the construction of residential buildings in Lagos State.The use of substandard materials for the construction of residential buildings within Lagos metropolis is experiencing a growing concern for both the government and the residents. The construction of half-lived and substandard buildings contributes to negative consequences ranging from rapid deterioration of building elements, premature failures of key building components, and sometimes building collapse. This study attempts to investigate the factors influencing the use of substandard construction materials for the construction of residential buildings in Lagos State. This research collected primary data through a cross-sectional survey of professionals engaged in the construction of buildings and building owners within the study area. Two sets of structured questionnaires were developed and administered to each of the groups of respondents, respectively. The collected data were analysed using descriptive and inferential statistical tools. The results show that factors influencing the use of substandard construction materials for the construction of residential buildings include corruption, use of quacks, contractor’s greed and selfish interests, and client’s financial constraints. The results suggested no significant difference in the perception of contractors and building owners on the factors influencing the use of substandard materials for the construction of residential buildings. The study concludes that the use of substandard building materials for the construction of buildings could cause structural failure, high maintenance costs, incessant building defects, and accelerate deterioration of building elements and components. Building clients suggest to engage professionals and refrain from patronizing quacks.