LITERATURE REVIEW
INTRODUCTION
The occurrence of building failure and collapse has become a great concern and a serious issue in the development and growth of this nation as the magnitudes of this incident is becoming very alarming Ademoroti, G. (1991). The building failure and collapse in Nigeria originated principally from bad design, faulty construction, use of low quality materials, hasty construction, foundation failure, lack of proper supervision, ineffective enforcement of building codes by the relevant Town Planning Authorities, lack of proper maintenance e.t.c. (Folagbade, 2001 and Badejo, 2009).. It has been revealed that more than 70% of the reported cases of building collapse in Nigeria temmed from the informal sector. It further showed that 70-0%, 23-3% and 6.7% of the reported cases occurred in private, public and corporate organizations respectively.
Building collapse, though a regular occurrence all over the world is more rampant and ruinous in the developing countries. The incidence of building failures and collapses has become serious problem of concern in the development of this nation as the frequencies of their occurrence and the magnitude of the losses in terms of lives and properties are now becoming very alarming. In fact, building collapse has now become a familiar occurrence, even to layman on the street in Nigeria. Failure in building can be described as the inability of the building components not being adequate to perform what are normally expected or required of those components. On the other hand, when part or whole structure has failed and suddenly gave way in a way that as a result of this failure, the building could not meet the purpose for which it was intended, the building has collapsed. Amusan, J. O. (1991). Cases of building collapse are not restricted by climatology or level of urbanization as they cut across cultural and ethnical barriers. Many cases of building collapse have been reported in Nigeria. For instance, Folagbade (2001) and Chinwokwo (2000) enumerated forty-two (42) cases of building collapse as occurring between 1980 and 1999 in Nigeria while Makinde ( 2007) listed fifty-four (54) cases occurring between January 2000 and June 2007 alone. Building collapse has also been observed to cut across the different categories of building – private, corporate or public. Folagbade (2001) showed that of the twenty-five (25) reported cases of building collapse between 1980 and 1999 in Lagos State, private (76%), corporate (12%) and government or public buildings (12%) accounted for these proportions. Also, building collapse is no respecter of size of the structure. Amusan (1991) reported that Barnawa flat disaster in 1977 was a three-storey building, a public building (Secondary School) which collapsed in March 1988 at Ibadan was two-storey building, the collapsed show-room for cars in Lagos in 1987 was just a storey building while that of the Primary School in IIoabuchi, River State in July 1991 was a bungalow building. Folagbade (2001) also reports that the Abuja building which collapsed in March, 1993 and the one at Ojuelegba in 1999 were both multi-storey buildings. The memory of the incidents of two separate building collapses that occurred at Ebute-Meta area of Lagos State and Kano State which killed several people in 2007 still lingers on.
Furthermore, 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 two sub-headings:
Conceptual Framework
Chapter summary
2.1. CONCEPTUAL FRAMEWORK
Buildings as structures which serve as shelters for man, his properties and activities are expected to be properly planned, desired and erected to acquire desired satisfaction from the environment. Factors considered here include; durability, adequate stability to prevent its failure or discomfort to the residents, resistance to weather, fire out break and other forms of accident. Badejo, E. (2009).
The frequency of building collapse in Nigeria in the recent past has become a major problem and concern in the development of the frequencies of their occurrences and the magnitude of the losses being recorded in terms of lives and properties are becoming worrisome and alarming. Even though, the proportion of building that collapse is very small compared with the vast majority that are in use, but there are human and material wastes associated with such buildings collapse. Apart from psychological wounds often inflicted on both the affected residents of such houses, the owner and the environment also constitute huge loss to the nation at large Chinwokwu, G. (2000).
The essence of environment management is to reduce the chances of vulnerability of the environment to disaster through prevention, mitigation, preparedness and capacity building. Going by this, it can be deduced that environmental management has the following components: Disaster management, Hazard management and capacity building. Because of the incessant disaster that is ravaging his world, agencies to undertake environmental management functions have been put in place in many parts of the world. Several causes of building failure had been attributed to their natural or man-made phenomena. A natural phenomenon may be attributed to earthquakes and landslides while man-made phenomenon consists of disasters which may be borne out of man’s negligence in areas such as soil type, building design and planning for extra loads and stress, foundation works, quality of building materials, lack or inadequate monitoring of craftsman and poor quality of workmanship. (Adebanjo .K :2005)
Causes Of Residential Building Collapse In Nigeria
In recent times, building collapse in Nigeria has been sources of major concern to so many people especially those associated with the building industry. It is so because there are so many cases of building collapse all over the world, Nigeria precisely. Most of these cases had resulted into massive economic losses in terms of lives and property. Building collapse is some of the cardinal issues which have created serious concern to all the professionals like Architects, Structural Engineers, and the Builders. The government also is worried about the frequency of collapse of buildings in Nigeria. However, Badejo, E. (2009) as quoted in Fakere et al (2012) admitted that the recurring event of collapse of building has forced some state governments to enforce and enact some laws recommending forfeiture of such buildings and prosecution of their owners.
Generally, causes of building collapse can be classified under seven major factors, namely;
Bad design
Faulty construction
Poor quality of materials and construction methods
Foundation failure
Fire problem
Natural phenomena
Inadequate Maintenance
Bad Design: Bad design does not only mean poor architectural design, but it involved some other professional’s design inputs. The Architect may contribute by starting design without adequate visibility study. This may include the authenticity of the land and nature, soil adequacy, site inventory and analysis. Others may include, inadequate or poor design details, poor supervision, sub-standard material specification and faulty or lack of maintenance schedule. Engineers may also contribute through failure to carry required tests such as foundation and soil analysis. It may also be through errors of computation, use of inaccurate data, improper choice of materials and ignorance of the effects of repeated stresses.
Faulty Construction: Studies have revealed that faulty construction contributed up to 40% to structural failures in building collapse occurrences. In many occasions, failure of contractors to build according to the plans and specifications or poor mixing and placement of concrete contributes largely to structural failures. Others may include formworks vertical or lateral overloading, unstable bearing support and premature removal, all these often leads to collapse of many on-going construction projects. Example of this is the collapse of the on-going construction of one-storey building, Benjamin Opara Street, Port-Harcourt, River State (2006) as a result of failure of structural members. These actions are often attributed to contractors’ inexperience, lack of care or high profit pursuits. On the other hand, poor inspection of construction materials and mix ratio by the Engineers may also aid the contractors to perpetrate some of their evils that often lead to incessant structural failures. In this case, contractors may use salty sand to make concrete, substitute inferior steel for the original specified, bad riveting or improper tightening of nuts, bad welding and so on, and all these may lead to collapse of building, if not properly done.
Poor Quality of Materials and Construction Methods: Use of inferior material is said to be up to 10% contributory factor to building collapse cases in Nigeria (Oyewande, 1992). Likewise, the use of blocks made by most block industries in Nigeria needs to be discouraged, due to failure of many block industries to use required measures. Mohammed (2004), asserted that while it is good to mix a certain quantity of cement by weigh t with an appropriate quantity of sand, also by weight, most block moulding industries in Nigeria prefer to mix these materials by volume. He further stated that most block making industries in the country use the same mixture of sand and cement to produce different sizes of blocks. In some cases, the steel reinforcement used for some project construction may be substandard. For instance, a batch of structural steel, which appear sound might have evaded the quality control checks and in fact could be of substandard quality. (Onyemachi and Uji, 2005). This attitude though very bad, but it is very common among the contractors who likes to cut corners by not using adequate materials as specified. The use of inferior materials and untested local building construction methods often leads to structural failure and eventual building collapse, if not adequately checked.
Foundation Failure: A building structure can collapse, if constructed on faulty foundation. Foundation of a building is that part of walls, piers or columns in direct contact with and transmitting loads to the ground. Building collapse as a result of foundation failure can be caused by construction of foundation on poor sub-soil, building not uniformly loaded/inadequate foundation, soil erosion and earth movements.
Fire Problem: Today, most of the available building materials in the developing countries are not only flammable but also encouraging the spread of fire (Adedoyin, 1983, Olagunju, 2002). This situation often makes a little fire ignition to spread very fast into a large scale fire development in buildings. Fire when fully blown out, both the
Structure’s reinforcements and concrete will be weakened. It is even worse, when the steel reinforcements are exposed to the naked fire, they may fail in the process to provide the necessary support for both the live and dead loads. In the event, it may lead to partial or total collapse of the building. It is therefore pertinent to use high fire resistant materials for building construction and for professionals in building industry to be fire safety conscious, most especially in material specification.
Natural phenomena: These may occur in the form of storm, flood, exceptionally high wind or hurricane, thunder, lighting, volcanic eruption and earthquake. These natural phenomena are referred to as “natural disaster” or “the act of God” (Onyemachi and Uji, 2005). Some of the aforementioned are possible factors that are largely responsible for most of the building collapse cases in Nigeria. From a newspaper survey conducted by Arayela and Adam (2001) on the reported cases of incidents of collapse buildings in Nigeria, it was revealed that many buildings collapsed as a result of rain storm. Example of these include, residential building, Ojuelegba road, Lagos (July, 1986), commercial building, ikorodu road, Lagos (September, 1987), 3-storey residential building, Iju-Ishaga, lagos (September, 1999) and so on. No one has power or control over natural occurrence , but may be minimized if Environmental Impact Assessment (EIA) is made mandatory to be made available by all developers or building approval applicants before commencement of any building project construction. This will help to determine the feasibility of constructing the building on the proposed site.
Poor Maintenance: Buildings start to deteriorate from the time they are completed and from that time begin to need maintenance in order to keep them in good condition. This process of gradual deterioration is unavoidable, but the speed at which it proceeds can be reduced through the manner in which buildings are maintained, (Olagunju, 2011). Thus, the rate of building deterioration depends largely on nature and manner of maintenance. Poor building maintenance can cause weakening of the building structure; most especially when unplanned maintenance type is the building maintenance culture or practice of the building owner/user.
Effects Of Building Collapse
Physical damage and psychological trauma are the aftermath effects of building collapse, the degree of which is often beyond easy prediction. Depending on the nature and extent of damage of building collapse incidents, the effects are felt almost in all human endeavours. These effects sometimes include loss of human life, and loss of materials and capital investments, as well as psychological pains.
Loss of Human Life: Loss of human life has become a common report of most of the collapse building incidents in Nigeria. From the newspaper survey conducted by Arayela and Adam (2001), about two hundred and seventeen (217) people were reported dead with many injured from only fifteen selected cases of building collapse between 1974 and 2001. It is an irreparable loss to both the victims’ relatives and the nation at large and thus called for the need to find a lasting solution to forestall its incessant occurrence.
Loss of Materials and Capital Investments: When building collapsed, most of its structural components and materials will be damaged often beyond re-use, while capital investments in most cases are not recoverable. This kind of situation, more than often leads to bankruptcy on the part of the investor and high economic implications on the nation’s economy.
Remedial Measures
The frequent collapse of buildings in Nigeria can be minimized if not curbed through adherence to some of the following measures, namely; Soil test, Environmental Impact Assessment (EIA) and structural analysis needs to be made mandatory to be submitted along with the building plans to planning authorities by all the developers or building approval seekers/applicants, especially for all institutional, commercial and industrial buildings.
2. All plans for approval must be made to pass through all the professionals associated with building industry working in every State/Local Government Development Control Boards before its final approval.
3. All plans for approval must be ensured to be in compliance with the Nigeria’s new building code and all the affected local government’s byelaws.
4. Inspection team must be made to regularly be on themove to inspect all construction works in their locality with the aim of enforcing the building code and the local byelaws.
5. All the professional bodies associated with the building industry in Nigeria, should jointly embark onenlightenment campaign for the public to be aware of the evils behind quarks involvement in building construction activities and the use of low quality materials, untested building materials and local construction methods.
OTHER REVIEWS
Structural failure has a much longer history than other types of buildings failures. Cowan (1989) investigated and stated that in the ancient world structural failures were often severely punished. For example, the legal code promulgated by Hamurabi, a Babylonian king (1792–1750 bc), stated among other things that if a builder has built a house for a man and his work is not strong, and if the house he has built falls in and kills the occupant then that builder shall be slain. This shows that there were building collapses in very distant time past and the government then set Code of Laws, first in history. It was a very harsh code dealing with the social structure, industries, law, economic conditions and family life. On the contrary, the Romans attitude to building collapses was not quite harsh. Cowan (1989) affirmed that there was also a tendency to make sure important structures do not fail by using materials generously, and that is, of course, one reason why so many of the Roman architecture survived till today.
In the European Middle Ages, structural materials were often used far more sparingly. The reasons were partly religious and partly economic. People were more inclined to look for supernatural causes of structural failure. With traditional materials, buckling was not a major structural problem, and multi-storey structures were rare. The emphasis was therefore on size of horizontals spans. In the Roman times, the arch and dome came into use for horizontal spans, with a consequent increase of several hundred per cent in the predictable length of spans. Arches, vaults and domes remained an important part of European structure thereafter.
Cowan (1989) further revealed that there was no structural theory of any sort before the fifteenth century, and none that was practically useful before the seventeenth century. How did the builders formulate their factors of safety? One may ask. The failure of arches, vaults and domes of bricks, stones or concrete occurred through the opening up of a sufficient number of joints or cracks to form a collapse mechanism. Collapse occurs when the line of thickness to span (where‘t’ is the thickness or depth of the structure and ‘l’ is its span), t/l, which depends on the dome. The minimum safe ratio of t/l could be determined by observing collapses. If the structures fell down, the ratio was too small. It would require a lot of observations, but structural innovation was slow. Egyptian temple structure hardly changed over 3000 years, and the structure of Ancient Roman domes and vaults and of the Gothic cathedrals developed slowly, in each case over a period of several centuries. Columns were usually grossly oversized, but comparatively long horizontal spans for collapse, that is, those that survived, many undoubtedly did collapse.
Scientific concepts began to play a role in structural design from the sixteenth century onwards, but the sizing of buildings remained predominantly empirical until, and well into nineteenth century. The main causes of structural failure were the inadequacies of these empirical rules, although there were other causes as well. Surprisingly, outright mistakes are still a major cause of failure today, they presumably always have been a cause, although one that might get lost within the inaccuracies of empirical rules. Poor construction has always been, and still is a cause of structural failure. A major cause of structural failure in the developing countries of the world is an inadequate understanding of the structural consequences of a new building technology. This would have been regarded as a minor cause before the eighteenth century when building technology changed very slowly, so that there was ample time to study the consequences of new methods and materials. Thus, there has been a very major change in the causes of structural failure. Lack of adequate theories and inadequate factors of safety had been the main cause of failure before the eighteenth century. No major failure since the end of the Second World War in 1945 can be attributed to that as asserted by Cowan (1989). In that area, the developed countries have therefore been spectacularly successful. Major structural failures are remarkably rare these days in the developed countries of the world; exceptions are, however, noticed in cases of man-made disasters such as terrorist attacks like the September 11, 2001 attack on the twin towers of the World Trade Centre in New York (Gjelten, 2008), or natural disasters such as the Tsunami disaster of December 26, 2004 (Tsunami, 2008).
According to Oyewande (1992), causes of building failures in Nigeria are attributed as follows; 50 per cent of the causes being 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. Fredericks and Ambrose (1989) 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, Akinpelu (2002) categorised the following as the major causes of structural failures: environmental changes, natural and man-made 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 carbonation and chloride ingress, cracking caused by overloading, subsidence or basic design faults, and construction defects.
Those that are usually first accused of professional negligence are the architect, structural engineer, the contractor and planning authority officials. The inability of the architect 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 the 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.
CHAPTER SUMMARY
In this review the researcher has sampled the opinions and views of several authors and scholars on residential building collapse, its causes and effects. The works of scholars who conducted empirical studies have been reviewed also. The chapter has made clear the relevant literature.