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CHAPTER ONE

1.1 INTRODUCTION

BACKGROUND

Buildings are constructed primarily to meet one of the human physical

needs. It provides accommodation for shelter, privacy, protection and

security for the man and his goods from the effect of weather and conducive

environment to stay warm and healthy.

Building comprises of main structural elements such as foundation,

walls, floors, doors, windows, walling and the root structure. These elements

must be adequately designed and efficiently constructed in line with relevant

building codes and standards, and in a way that provides expected conditions

compactable and appropriate for the activities to be carried out within it on

completion. It must also ensure the comfort and safety of the occupants.

The interior of the building must be well arranged in terms of shape

and size as to exclude noise, ensure adequate ventilation, natural lighting.

The material must satisfy the basic functional requirements of weather

and fire resistance, sound and thermal insulation, strength and stability,

durability and resistance to wear and tears.

It must be able to safety carry all the superimposed loads and transmit

it to the ground.


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It has been observed that following technological advancement and

increased passion for housing, it is widely reported in various electronic

print, news and media of incessant collapse of building structures all over

the country within the last two decades. This phenomenon of collapse is

becoming and creating a nightmare because of the time, energy, resources

wasted and especially the possible loss of lives. The high incidence of

building collapse calls for concern in the building industry today and also

the need to providing an immediate and lasting solution to the supervision

and construction of building from inception to completion is the campaign

the Nigerian Institute of Building in collaboration with the council of

Registered Builders of Nigeria (CORBON) is promoting today to enlighten

the public.

The Africa Newspaper of Nigeria (1999) reported that three different

buildings in various part of Lagos collapsed during a down pours, killing at

least five persons and wounded at least five others. This incidents bring to

four the number of such collapsed buildings in Lagos in four days. In all

cases reported in the past and recent times, it has been noticed that the

phenomenon of collapsed buildings occurs during, immediately and after the

construction.


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In view of the above, this research work will assess some of the

collapsed buildings in Nigeria with particular emphasis on the South

Western State of Nigeria by identifying their causes and proffering solutions

through a well design tools.

1.2 STATEMENT OF PROBLEMS

The increased reports of the high occurrence of collapsed building in

various parts of the country have been generating a renewed interest in the

building industry among the professionals. These professionals are not only

worried by the increased rate of collapse, but because of the consequent

economic losses, due to loss of lives, resources and time in addition to the

psychological effect of the horrible sight of the a fear math and resulting to

shame and disrespect it is causing to the members of the profession.

The research work will examine the causes of building collapses and

proffer solution to the problem through a well design technology

management.

1.3 AIMS AND OBJECTIVES OF THE STUDY

The research is to assess factors that causes collapse of building In

Nigeria while the research objectives are to

(a) Identify the factors that influence the occurrence of the collapsed

building


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(h) Investigate the impact of building collapses on the stakeholders.

(c) Assess the level of compliance of the National Building Code by the

Nigerian building industry.

1.4 SIGNIFICANCE OF THE STUDY

The study will provide technological assessment of the building

collapsed in Nigeria with the need to alert the stakeholders and the general

public about the losses and implication of collapse of building in order to

avoid future occurrence. Also the research work will provide information

that would assist the government in implementing the existing framework

and strategies for enforcing the National Building code in the building

process.

1.5 SCOPE OF THE STUDY

The study is expected to cover the whole country, however because of

the relatively large size of the country, it will be too expensive, as such the

scope of the research will be limited to the south western states of Nigeria

with various classes of buildings and having about the highest report of the

collapse of building structures in Nigeria References will be made to some

collapse buildings in some other states of the federation.

The research will not cover such issues as the structural design and

detailing of building structures, which is purely a structural Engineers work.


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CHAPTER TWO

2.0 LITERATURE REVIEW

2.1 BUILDING FAILURE

Jolade (1989) states that building failure should not be taken to mean

only a structural failure but is also include its non-performing with the

requirements expected of it, Failure in building can be defined as a defective

construction, integrated by other factors such as structural, functional,

material and environmental resulting in a short fall in performance occurring

at any time in the life of the product element or dwelling in which it occurs.

Common examples of building failure were listed to include such defects as

cracks in walls, deflection and overturning of beam, etc majority of these

failure arise during construction period or after while others are due to

natural phenomena

2.1.1 BUILDING COLLAPSE

This may arise as a result of failure in building, as the failure get to an

uncontrollable measure Collapse of a building may be either a partial,

progressive and total or sudden collapse. The effect of any collapse of a

building can be so detrimental as to cause loss of live, properties and waste

of resource. A colossal waste is normally recorded as collapse of building

occurs,


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According to Salau (1990), different types of building have been

known to collapse in use in contemporary history The story is now limited to

Nigeria only as Roman Point block of flat in London was known to have

collapse in the past, so also was famous Congress Hall, built by the

Americans with prestress concrete after twenty-three (23) years life span, in

the West Berlin, Germany Multi-storeyed Hotel in Madrid, Spain also

collapsed killing many of the occupants- The cause of failure of the skyline

mega apartment building in Fair Fax country, Virgina, U S.A- was

documented in the concrete international magazine of July, 1983 as due to

non-adherence to good construction practice.

There are basically three forms of collapse. These are:

- Partial Collapse:- This occurs when part of the building is .affected, i.e.

only a small fraction of the building or one side of it falls down

- Progressive Collapse:- In this type of collapse, there will be signs of

weakness noticeable either by seeing cracks which becomes widening with

time or by noticing unusual sound in the building due to structural member

gradually giving way from each other.

- Total or Sudden Collapse:- As the name implies, it happens when the

building falls down suddenly it may not even given any sign prior to falling

down


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2.3 CAUSES OF COLLAPSED OF BUILDING STRUCIURES

The major causes of collapse building structures could be traced down

to the defective structural design of the building elements with neglect of the

basic considerations of design procedures including under estimation of the

ground bearing structures. Ometar ((987) attributes the cause to a neglect of

real professionals advice whereby the owner prefer to build the house either

with half-baked professionals or the use of artisans and labour as a means of

direct labour contract. Iyagba (2000) averred that major causes of building

collapse are.

a. Absence of planning approval

b. Where approval was obtained, clients and contractors do not

adhere to the details of the approved drawings.

c. Proper soil investigation not carried out.

d. Engagement of quacks and half-baked professionals to take charge

of the construction

e. High cost of building materials prevents contractors from adhering

to the specifications in terms of quantity and quality.

f. Inadequate staffing of the Town Planning Authority combined with

inadequate qualifications for the job of monitoring and control of

building activities


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g. Town Planning Authoritys slow approval process and unnecessary

demand of certain documents in (such as Certificate of Occupancy

which are not easy to come by) respect of ownership of the land

which makes approval impossible or slow. This could also deterred

people from bringing plans for approval

h. Designers inability to effect compulsory and regular inspection

Ogunwasi (1999) however commented that in all the buildings that

have collapsed so far in this country, no professional builder has been

involved in the planning and management of the construction works.

Salau (1996), however grouped all the causes of structural failure and

collapse of building to occur under four basic stages of the building life as

in:

a. Planning stage

b. Design stage

c. Construction stage

d. Service stage

It is worthwhile to discuss how collapse can occur in each of these stages

2.3.1 Planning Stage

This is the first stage in any building process and of course a very

important stage that must not be overlooked in order to avoid unnecessary


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abortive work, defective overall scheme and escalation of design cost arid

expenses. According to Salau (1996), the service of an architect is usually

required at this stage, who will get other professionals actively involved

right from the conception and at the initial stage of formulating basic

planning. The primary consideration at this stage is function of which the

building is to be put. While the secondary consideration may include

aesthetic, sociological, legal, financial, economic, environmental or

resources consideration.

In terms of functional consideration, it should be realized that a

building plan for a particular purpose should be used for that same purpose

For example, if a building was originally planned to be used for residential,

it may not be safe for some building to he used for church congregation,

neither should a building planned to be used as office or residential be

converted to be used for the purpose of school. This of course is one of the

factors that led to the collapse of building of Saque comprehensive College,

Port Harcourt, in Rivers State Report of the findings submitted to the

Judicial Commission of enquiry by the Council of Registered Builders of

Nigeria (CORBON). Also reported that cases of building collapse at

Idumota have been reportedly traced to some office apartment being

converted to storing automobile spare parts (Salau, 1996).


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Also worthy of mentioning is the feasibility and viability studies of

the overall project work. The role of every professionals to be involved

must be defined. A quantity surveyor should be seen to be very prominent in

the areas of cost advise The method of tending arrangements, and selection

of the right contractor. Furthermore, decision should be made as to carrying

out of preliminary sub-soil site investigation. Many buildings too have also

collapsed due to non-availability of the sub-soil site investigation. Even

though many developers see this investigation as a waste of time and money,

it should be noted that properties of soil strata varies from one site to

another, It is very important to determine the geo-technical situation of the

site before commencing on any design. Many buildings failed due to

improper foundation, which is caused by non-availability of the subsoil site

investigation or non-compliance to it Foundation failures may be costly to

rectify and can involve expensive remedial works to the superstructure.

Every Naira spent on having a proper subsoil investigation carried out is

therefore a worthwhile insurance premium for the clients investment and the

professional reputation of all concerned with the project.

2.3.2 Design Stage

This may be in form of architectural or structural design. The

Architect is required to produce very good drawing to suit the requirements


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of the owner The Structural Engineer on the other hand produce structural

design concern with providing stable and robust structures for carrying

require loads and safely transmitting the vertical loads and horizontal

disturbing forces to the ground with suitable foundation.

According to Ambrose (1988), the design should address the

following basic issues,

a. The load sources and their effect

b. What the structure accomplishes in terms of its performance as a

supporting, spanning or bracing element.

c. What happens to the structure internally as it performs it various

tasks

d. What is involved in determining the necessary structural elements

and systems for specific required tasks

Makinde (1996) agreed that no matter how expert one may be,

everybody is prone to make mistake one way or the other, hence, and the

detailing of any structural design must be cross checked by the official of the

Town Planning Authority with a view to detecting any faults from the details

and / or calculations of the Structural Engineer and get the designer to rectify

such faults. Where they arc in doubts, both parties should meet to iron the

grey areas out. Makinde (1996), stated further that where such faults are not


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detected by the authority both the designers and officers of the Town

Planning Authority are to be blame if the building is built in accordance with

the design and specifications should he clearly put together as unrealistic

specifications or but it collapses in the long run. The material strength and

aggregate sizes should be clearly stated on the drawings to avoid

misinterpretation and that working drawings and specifications should be

clearly put together as unrealistic specification or unclear working drawings

can lead to collapse of the building.

2.3.3 Construction Stage

This stage is the most critical and sensitive stage in the building

process as any fault or omission can result into ultimate failure and collapse.

This is a stage when the work done in the planning stage and the design

stage explained above will be implemented. Where a building collapse as a

result of workmanship rather than design, the builder is to be blamed for it.

Akintunde (1990) stated that good design must be faithfully reproduced in

construction or fabrication and this includes good workmanship and use of

the specified quality of materials in the construction. To ensure this,

adequate construction supervision must be available especially to solve

problems that may not have been foreseen during design.


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Reasons why collapse buildings during construction stage are as

follows:

a. Many contractors do not know the technique involved in the job

neither do they have enough idea of the materials they are using.

b. Because of lack of enough practical training especially for artisans

and craftsman, quality work within the industry are in decline.

c. Many clients are self-contractors without any training in building

technology and coupled with inadequate staffing, inexperienced and

unqualified personnel tend to all sorts of constructional problems.

d. Rushing of construction work to complete on time also affect the

quality of work on site. Example is the removal of shuttering arid

form-work before the concrete is adequately cured (before 28 days

from casting date).

e. Refusal by clients to pay design architects and engineers for

supervision during construction work can lead to a situation where (he

contractor will choose to modify the design to suit himself with a view

of making more profit

It is the responsibility of the design engineer to see that the materials

specifications as well as testing of the basic materials used are

complied with. In some cases where contractors has rushed a job


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before the engineer comes for checking, the contractor may be

required to open up for inspection.

f. In most public buildings e.g. churches, mosques, town hall, etc

committee are normally constituted by the members of the community

without any of them being a professional and construction are carried

out by the committee as a direct labour exercise.

According to Akintunde (1990) the reason outline above is typical of

the reasons behind the collapse of many buildings in Nigeria as

investigation carried out by Nigeria Institute of Structural Engineers

concerning the live storey building located on a plot adjacent to 109

Western, Avenue, Iponri Lagos State revealed that:

a. The building originally existed as a single storey block (bungalow)

b. The owner who acted as his own contractor, decided to add many

more storeys (floors to it).

c. There is evidence of a planning permit of only one additional storey

d. That the Town Planning Authority discovering the contravention,

marked it for demolition, the owner went ahead with construction at

nights until the collapse occurred during the concreting of the fourth

floor.


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e. No professionals were involved in the design, construction and

supervision of the project

2.3.4 Service Stage

This stage has to do with the building after construction especially

where the building is being occupied The question that now arise is what

purpose was the building designed for originally and what purpose is it now

being used for? If the building is not being used for the purpose for which it

was designed, there is likelihood of problems or failure occurring. Salau

(1996), stated categorically that the collapse of Idunshage Street, in Lagos

Island in 1987 was due to this fact. Therefore any building that is to be used

for any purpose order than that which it was designed must be referred to

Engineer for further consideration. The major causes of collapse of building

during the service period were attributed to misuse as well as new projects

developed around the vicinity of the building. Similar cases to this was

given to Masha and Bode Thomas areas where pumping of water in the

adjacent plot during foundation construction or using of precast piles have

seriously affected existing structures which were earlier on stable

structurally.

Another similar area where failure occurs in building during its

service life is where the building lack maintenance Adenuga (1999), stressed


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that our buildings (both public and private lack adequate maintenance care

or attention, and that they are in very poor and deplorable conditions of

structural and decorative disrepair). However, lack of maintenance of

building can lead to collapse from accidental, circumstantial, weather or

time-related defects. Leakage of water due. to bad plumbing installation or

blocking or the drains can weaken structural elements He also states that

pounding of yam with mortal and pestle on suspended floor can cause

collapse of the building. Makinde (1996) however view the maintenance

issue criticaLly by saying that the deterioration does not only affect the

services and finishes but also the structures.

2.4 COLLAPSE OF BUILDING RESULTING FROM

FOUNDATION FAILURE

Chudley (1988) define foundation as the base on which a building

rests and its purpose is to safely transfer the load of a building to a suitable

depth below the subsoil. The requirements of any good foundation is stated

in Building Regulations 4, that all foundations shall:

a. Safely sustain and transmit to the ground the combined dead and

imposed load so as not cause any settlement or other movement in any

part of the building or any of the adjoining building or work


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b. Be of such a depth or be so constructed as to avoid damage by

swelling, shrinkage or freezing of the subsoil.

c. Approved document recommends foundations to be capable of

resisting attack by deleterious materials, such as sulphates in the

subsoil.

Foundation being the part that carried the whole building becomes the

first suspect when a building collapses.

2.4 CAUSES OF FOUNDATION FAILURE

Ajayi (1988) states that foundation failures may be due to any or

combination of any of the following factors:

a. Absence of proper site investigation or wrong interpretation of the

results of such investigation.

b. Faulty design of the foundation

c. Bad workmanship in the construction of the foundation; and

d. Insufficient provision in the design construction for exceptional

natural phenomenon such as thermal and biological conditions.

rainfalls and floods greater than those hitherto recorded on the site.

2.4.1.1 Lack of Suhcoi1 Investigation

All building structures, no matter their size, shape intended purpose,

type of construction or use share a common thing. They all rest on the


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ground. Since soils at different point have different properties, subsoil

investigation therefore is a pre-requisite before the design of any foundation

is made. The parameters obtained during the site investigation are used in

developing the most appropriate, economic and safest foundation.

Conclusion can also be drawn from the result of site investigation as to

whether to use the site of to look for another one especially where the

investigation reveals an expensive foundation to be provided.

Omange (1988) states that the need to have a feeling of safe housing

and environment necessitate the carrying out of the site investigation.

However most developer used to run away from carrying out site

investigation as they claim that the cost will increase the total cost of the

building, it is only necessary for a very big project such as high rise, darns,

road project, etc. based on this fear regarding cost, Jack (1983) made it clear

that the cost of an exploration vary with the type of structure and the nature

of the soil but is to compared with the total cost of the building. The cost of

site investigation range from 0.1 to 1.0 percent of the cost of the structures

and is even lower for large jobs because the fixed charges for selling up an

exploration do not vary with the size of the job

Neglect of soil investigation may however leads to excessive

settlement as a result of over-stressing of the soil beneath the buildings,


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differential settlement, undercutting of foundations etc. are the result of

neglect of site investigation

2.4.1.2 Collapse Due to Poor Design of Foundation

Majority of the problems of building arises as a result of lack of

sufficient care in the design and construction of the various building

elements, chief among them is the foundation. Designers concerns range

from basic understanding of structural behaviours of the determination of the

construction details for a specific type of building Ilesanmi (1988) is of the

opinion that most designers, architects arid engineers sometimes fail to

appreciate and visualize possible structural behavior of various

constructional details in general use

Ajayi (1988) emphasis the need to give adequate consideration to the

use of appropriate design guides and data and that designer must ensure that

settlement is not large enough or vary relatively. It is equally good to note

that some changes normally occurs in the subsoil after the superstructure has

been erected, due to the effect of filing, excavation and groundwater

fluctuation due to weather, flooding, drainage or down water, etc

2.4.1.3 Failure of Foundation Due to Poor Workmanship

Very good design of foundation coupled with rightly placing of

substructure reduce problems in the whole building after completion as well


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as reducing future maintenance cost. It has been observed that most structure

collapsed as a result of using poor materials in the construction or by using

poor workmanship. This is usually practiced due to economic reasons. Most

contractors believe that by compromising the standard of materials and

workmanship, they will earn more money.

The major causes of damage to shallow foundations is from settlement

of poor slab due to inadequate compaction of infill or use of inappropriate

fill material To avoid settlement therefore, backfilling of excavations around

completed building should be with suitable material placed in thin layers not

exceeding 200mm thickness and compacted to a high standard (Seeley,

1980).

2.4.1.4 Failure of Foundation Due to Natural and External Influence

These include those factors that are not immediately possible to

foresee the extent of damage they are likely to cause, such as scour, seepage,

floods, extremes of temperature, biological and chemical effects, etc

2.4.1.5 Foundation Settlement and Movements

Ilesanmi (1988) lists factors responsible for foundation movement

among others to include the following:

a. Seasonal weather changes

b. Vegetation growth and removal


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c. Subsidence

d. Soil shrinkage

e. Made up ground

f. Movement resulting from eccentric loads

Consideration should not only he given to bearing capacity of the soil

on which a building is to be placed, but very importantly is the settlement,

which must not be large enough or vary relatively to an extent that could

damage the structure or impair its functions. The most important

consideration for a reclaimed land should be the magnitude of settlement,

both residual and that induced by a shallow foundation or the effects of

negative fraction forces on a piled foundation.

2.4.2.1 Soil Problems that Normally Causes Failure of Foundation

* Expenses Soils

This is due to behavior of soils as the water content increases or

reduces when the soil is dry, fine-grained soils shrink to a minimum value

resulting into vertical cracking to a considerable depth.

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