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| Building under construction collapse |
Failures of
Engineering Structures do no just happen. Often someone is responsible in Kenya ; we have
recently witnessed buildings collapsing when under construction and even after
they have been completed. Less reported are roads that fail prematurely.
Structures do not fail due to architectural issues. Almost in all cases,
failure occurs due to an engineering and or construction related problems.
There are a variety of reasons why engineering structures fail. The principal
among them are:
(a)
Inadequate geotechnical and materials investigations.
(b)
Using inappropriate specifications and manuals.
(c)
Incompetent design.
(d)
Poor workmanship.
(e)
Lack of ethics.
(f)
Poor supervision hence poor construction.
(g)
Close relationship between parties to the contract
(h)
Using inappropriate materials
(i)
Weak laws
(j)
Corruption
1 Inadequate geotechnical and materials
investigations
It is mandatory
that comprehensive geotechnical and materials investigations are carried out
for all engineering structures. Whether you are constructing a building, a
road, a dam, aircraft runway/taxiway, pylons to carry electricity or
telecommunication masts, geotechnical and materials investigations are not
optional. Sadly, this is one area that is usually neglected or inadequate
resources are allocated for the exercise. This is either due to ignorance or
the promoter has the false notion that he can save money by carrying out
minimal investigations or none at all. The consequences are usually
catastrophic since the whole design of the proposed structure is based on wrong
assumptions. Nature is usually
unforgiving to those who ignore this phase. (Typical example of this is the
Kiambu residential structures that collapsed in 2010)
Remedy
Approval to
proceed with the construction of major structures should at all times be
subject to production of authentic reports that give evidence that comprehensive
materials and geotechnical investigations have been carried out and design of
the foundation is based on the test results obtained. Inclusion of appropriate
factors of safety must be demonstrated.
Never cut costs by carrying out inadequate investigations.
Specifications
and Manuals are usually the principal guides to a designer. It is important that the designer uses the
correct, relevant and most up to date Specifications and Manuals. To update Specifications and Manuals, lessons
learnt from failure of constructed structures and research is important.
Remedy
The government
must invest in research and performance monitoring of completed
structures. Specifications and Manuals
must be reviewed and amended on regular basis if found necessary. It is important that the private sector and
universities are involved in these exercises.
A number of
projects being implemented have been designed by persons who are not qualified
to do any design. Others have been designed by inexperienced professionals but
no review is carried out by qualified and experienced professionals. Promoters engage these kinds of people to
save on design costs. The consequences
are often catastrophic.
Remedy
Heavy fine
or make it a serious criminal offence
for one who does not possess a practicing license as an Engineer to design or
approve design of engineering structure. Engineer’s registration body’s act
should be implemented to the letter. Audit work should be carried out on all
ongoing or recently completed major engineering structures.
It is important
to state that the responsibility of constructing an engineering facility that
fully complies with the stipulated specifications fully lies with the
Contractor. The Engineer, if indeed
there is one on site, will monitor the quality of works but his approval or
otherwise of the works will be based on samples tested. This is due to the fact that it is
practically not possible to carry out 100% testing of the materials used in the
works. A good Contractor will therefore
ensure that he only entrusts his works to persons who are competent and have
integrity. He will ensure that his
workforce has the right gear, appropriate equipment and machinery for the tasks
at hand.
Remedy
Contractors
should be penalized heavily for any structure that collapses during
construction or after completion, if proved negligent. Construction work should only be supervised
by qualified persons. Regular audits
should be carried out while construction is ongoing.
Ethics is a
strange term to a number of Contractors and even supervising engineers. A
Contractor who has a workforce that values professional ethics will require
minimal supervision. Any Contractor or
Engineer who wishes to stay relevant in the market in the long term must
embrace professional ethics. Needless to
say, this will always lead to high quality work, all things being equal.
Remedy
Contractors and
other professionals involved in the construction industry, who continuously
demonstrate lack of professional ethics, should be struck off the register and
be black-listed for a period to be defined in law but should be punitive
enough.
It would be
hypocritical not to admit that engineers and their support staff do not
contribute to failures of structures that we see all around us. In a number of cases, this could be due to
the fact that those employed to supervise are inexperienced and may not know
when to reject materials or completed works. The problem in this case can be
traced to procurement of consultancy services where the cheapest gets the
job. A Consultant who tenders low is
unlikely to engage experienced and competent engineers and support staff. So at the end of the day, the Employer will
get what he is ready to pay for. Poor supervision will also be witnessed on
sites where the engineer and/or his support staff have been compromised by the
Contractor. So they look the other way
when things are going wrong.
Remedy
Only engage
competent and experienced persons with integrity to supervise the works but
keep them motivated and well remunerated.
As we all know,
parties to the contract are two: the
Employer and the Contractor. As a matter
of fact, close relationship between the two parties is not wrong in itself. It could even be beneficial to the project in
certain respects. The problem arises when this relationship becomes too close
for comfort. The Engineer, though not
party to the Contract, finds it very difficult to fulfill his roles and
responsibilities since the contractor will only listen to the Employer.
Unfortunately, the Employer, who may be the custodian of taxpayer’s money, will
not be on site to see things going wrong.
The Contractor will ignore the Engineer’s instructions since the
Employer “is already in his pocket” but the engineering facility constructed
may not stand the test of time.
Remedy
The Employer and Contractor should at all times
respect the impartial role played by the Engineer.
Strict quality
control of all materials used in engineering structures is mandatory. Taking shortcuts often lead to catastrophic failures.
Materials must be tested for compliance with stipulated specifications both at
source and once it is delivered to site.
Before placement, materials must be mixed as required. For instance, concrete must have the
different aggregates and cement in the right proportions and only the right
amount of water should be added. When
ready, concrete must be placed on clean reinforced or un-reinforced surfaces
within the required time. It must be vibrated thoroughly and cured for the minimum
number of days stipulated before proceeding with construction. But what we see all around us are concrete
structures that are constructed in a hurry and loading allowed before concrete
attains the required strength. This is
true of all other engineering materials, stabilized materials, bituminous
materials and so on.
Remedy
Always ensure
Materials are tested for Compliance with the Specifications and Quality Control
is then performed at the recommended frequency.
9 Weak Laws
When an engineering structure
collapses it often leads to loss of life, injuries or improper use of
tax-payers money. In all cases, those responsible must be made to pay
dearly. It is usually a mockery of
justice to release those found guilty of negligence on a small fine of KES 50k.
Remedy
We should review our laws and
make punishment for all those who approve, design, supervise construction or do
the actual construction of unsafe structures so severe that no one in his right
mind would want to be caught on the wrong side of this legislation.
This is perhaps
one of the most difficult problems to tackle.
Over 50% of the causes discussed above would be solved if we could
tackle this vice. Unfortunately corruption is now almost an accepted way of
life especially in Africa . And if it is any consolation, it is a
world-wide problem and only the degree is different.
Remedy
Punish
severely those who perpetuate the vice, motivate and remunerate well those
dealing with engineering structures handsomely but above all seek Divine
Intervention
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