Building Failure Filed in Civil Engineering, Construction Industry, Construction Technology on Oct.04, 2009 by Mohammed Azad Hossain Building components tend to fail depending on materials, designs, method of construction, environmental conditions and the use to which the building is put. Substandard materials and design errors are major causes of component failure. Some of the main causes for building collapses are bad design, faulty construction, foundation failure, extraordinary loads, unexpected failure modes or a combination of causes. But collapses also occur due to natural disasters such as earthquakes, floods, hurricanes, cyclones and fires. Common design faults All structures are designed to support loads without deforming excessively. These loads include live load, which is the weight of people and objects, rain and wind, and the dead load of the building itself. Internal factors/human errors The internal factors for bad design don’t only mean errors of computation, but a failure to account for loads the structure will be expected to carry, erroneous theories, reliance on inaccurate data, ignorance of the effects of repeated or impulsive stresses, and improper choice of materials or misunderstanding of their properties. The structural engineer is responsible for these failures, which are created at the drawing board. Sometimes failures occur due to obvious negligence or gross human error. The external factors
These are often natural, such as extraordinary loads, heavy rain, earthquakes, hurricanes and a defective site, with very unusual ground conditions, like sinking holes or swampy land. A building that is intended to stand for some years should be able to meet all these challenges. This is incorporated into the design. Identification of the characteristics of particular site conditions by the engineers/consultants, through suitable geo technical studies, can help with site selection and site progress that reduce the risk of failure. Inadequate awareness Many structural failures have been the consequence of poor technical research and knowledge. As technical awareness gets better, errors are becoming by far the major cause of known structural collapses, mainly in technologically advanced countries. An error in this situation is a gross error or mistake, not a negligible computation error or construction divergence. Common construction faults Inappropriate construction The contractor’s failure to build in accordance with drawings and specifications can also add to failure of structures. Use of inferior or substandard building materials is another reason buildings fail. Overloading during the life span of a building can critically weaken the structural reliability of it. Extra loads due to unauthorised change of use or additions and alterations to the structure can intensify an under-designed building and can contribute to its eventual failure. Performance failures Performance failure can be described as an intolerable difference between anticipated and existing design and construction. The engineer’s design interpretation must be put aside at the construction stage for the structure to be effectively constructed.
Failure may occur due to consultants’ and contractors’ inadequate supervision and control of site operations and quality control. Such errors ultimately lead to a situation, which may involve such failures, which are related to excavation and equipment, inappropriate sequencing, not enough temporary support; unnecessary structure weight; untimely taking away of shoring or formwork; and non conformance to design objectives. Common material faults Most structural failures are associated with materials and are the consequence of human error involving a lack of knowledge about materials or the combination of contrary materials. There are structural failures that can be endorsed to irregularity in materials. Although much reliance is given on modern structural materials, the manufacturing or production faults may exist even in the most dependable structural materials, such as standard structural steel. Stone frontage sheets or glass curtain walls may have hidden serious faults. Prevention Most of the structural failures (other than those caused by natural disasters) have occurred due to such faults, which are controllable. Good operational planning and detailed deliberations can save the failures of the valuable structures. The well-designed structures, coupled with the hard effort of the experts and correct materials can ensure the structure a complete success. Some other important points of failure prevention are: Professionalism It is of extreme significance for building professionals, including builders and government bodies, to understand that the design process does not stop at the conclusion of design drawings and specifications. The design aim must take second place in the construction stage.
Increased antagonism during construction bidding, along with developers’ aim of profit making, can place intense pressure and demand on the engineers/consultants to create the most inexpensive and efficient design. However, this should not compromise safety. Building experts have a great liability to make sure that the safety of the buildings and infrastructures is to the maximum. Statutory bodies should be more proactive in imposing strict regulations in building design, codes and standards and impose penalties for the violators. Integrated efforts by all parties Consultants and contractors must have total control of site operations and quality. Site staff are required to be well qualified and competent and correctly trained in the trade in which they are working to ensure good workmanship and high quality of building works. Independent inspections by statutory bodies are essential to make sure that the building is constructed in accordance with approved plans and specifications. A check system must be utilised to assess the integrity of structures based on the professional engineer’s design and to give independent design results to ascertain the sufficiency of the major structural rudiments of the buildings. The recognised check should therefore give particular concentration to unusual design details. The inspector and checker should concentrate on significant areas such as transfer beams and columns, and the centre of attention should be kept on areas where errors are critical and frequent. Conclusion Design is a human endeavor and thus it is subject to error. Due to this, some designs are destined to fail.
In case of a building failure there must be a transparent investigation with professional engineers and forensic experts experienced in identifying the root cause of failure. And having found the possible causes of the failure, it is vital to know how to avoid it in the future. The primary step in preventing building failures is to develop a programme for educating all parties on lessons learnt from past failures. It is not advisable that a mistake once committed and affected is repeated.Many decisions in design are based on engineering judgement, but not only on the understanding of theory or any computational tools. Even experience in extensive design in academic context can provide only limited perspective in engineering decision making. Most lessons in engineering decision making come from the cases of histories of failures of structures, which itself are the results of a bad judgement, thus making us understand the pitfalls in conceptual design. From these experiences from past, the common causes of structural failures are understood. The most common causes of structural failures are: (1) Poor communication between the various design professionals involved, e.g. engineers involved in conceptual design and those involved in the supervision of execution of works. (2) poor communication between the fabricators and erectors. (3) Bad workmanship, which is often the result of failure to communicate the design decisions to the persons, involved in executing them. (4) Compromises in professional ethics and failure to appreciate the responsibility of the profession to the community at large could also result in catastrophic failures. Other common causes of structural failure are: (5) lack of appropriate professional design and construction experience, especially when novel structures are needed.
(6) complexity of codes and specifications leading to misinterpretation and misapplication. (7) unwarranted belief in calculations and in specified extreme loads and properties. (8) inadequate preparation and review of contract and shop drawings. (9) poor training of field inspectors. (10) compressed design and/or construction time. 5 Guaranteed Solutions to Building Collapse in Nigeria BY Jumia House 30 April 2015 Miscellaneous
On Sept 12th 2014, a six-storey guest house belonging to the Synagogue Church of All Nations collapsed, killing over 100 people and most of them where foreigners. The reason for the collapse is still under investigation but according to reports, the building was originally a two-storey building said to be less than four years old, which the church decided to expand. It was also reported that the building had no approval from relevant agencies of the government.
This is one of the tens to hundreds of building collapse cases in Nigeria with each of them having its own reason for collapsing. The frequency of collapse building structures in Nigeria in the past few years have become very alarming and worrisome and many lives and properties have been lost.
A visit to the collapsed scenes makes one to wonder why such a building should have been allowed to stand in the first instance and also reveals the extent people can go to cut corners at the expense of property, safety and lives.
This is a follow up to the conversation that matter I started on Unite Nigeria on why building collapse in Nigeria where I shared several insights from different perspectives on why buildings collapse in Nigeria, you should read it, the statistics are staggering!
But in this article, I will be sharing 5 guaranteed solutions to building collapses in Nigeria. My goal is to add to the general body of knowledge out there from my own personal 9 years experience in Nigeria’s construction industry as a professional building contractor.
Strict Adherence to Quality Building Materials
Experts have revealed that one of the major causes of building collapse is the failure and lack luster effort of building contractors to pay strict adherence to quality building materials. A research by the Standard Organization of Nigeria indicates that poor quality building materials are major causes of building collapse in Nigeria. The research pointed directly at cement because most cement used in building construction does not hold other particles strongly.
From a professional point of view, there are three cement types presently in use worldwide, which are 32.5mpa, 42.5mpa and 52.5mpa.
The 32.5mpa can only be used for plastering and block making. The 42.5mpa is for multipurpose usage such as block moulding, concreting, slabs and high rise buildings but it can’t be used for plastering. The 52.5mpa can be used for high density works such as bridges, embankments, dams and retainer walls. Therefore to ensure the avoidance of building collapse, builders should always ensure that the right cement specification is used for the appropriate construction types.
The RIGHT Human Resource
Another major guaranteed solution to building collapse in Nigeria is the employment of the right human resource to any building and construction project. To ensure that the right human resources are engaged in building and construction projects the following steps should be adhered to;
Engagement of professionals and competent workforce: Contractors in other to cut the cost of projects, most times engage the services of non–professionals who are not licensed to engage in any building projects. Experts have blamed incompetent artisans and weak supervision of workmen as one of the major reasons of building collapse. It is generally said that the best way to manage a crisis is to avoid it, it is advisable that the best way to manage crisis resulting from building collapse is to prevent it by avoiding the use of quacks and non building professionals in any major building projects.
Training and retraining of building practitioners: All relevant building regulating bodies should ensure constant continuous education and professional development of its members that will help them update their skills and knowledge.
The RIGHT Design Structure
Having the right design structure is a guaranteed solution to building collapse. Building contractors should ensure that their designs are reviewed and approved by appropriate authorities before construction begins. This is so because most designs in Nigeria are copied from other countries without considering the conditions that led to such design.
Bad design does not only mean poor architectural design, but it involves some other professional design inputs. To get the right design structure, it is advisable that the contractor engages the services of a building designer. The areas to look out during design to guarantee reduction of building collapse includes;
Designers should ensure adequate feasibility study on the authenticity of the land and nature, soil adequacy, site inventory and analysis. Ensure the avoidance of inadequate or poor design details, poor supervision, sub-standard material specification and faulty or lack of maintenance schedule.
Proper Maintenance Culture
Poor maintenance culture is another factor that can lead to building collapse. The truth is that even the best constructed buildings need constant attention and if the attention is delayed, what can start as being something very minor is liable to turn quickly into an expensive man-made disaster.
No building can exist throughout its lifespan without the need for one form of maintenance or the other. Experts believe that maintenance work commences on the day the contractor leaves the site.
The necessity for maintenance work on buildings is noted in the fact that all buildings as well as the materials and components therein, deteriorate or suffer loss in aesthetic, strength and or functional value with exposure to the elements of weather over time.
The following strategies can be used to ensure proper maintenance of a building;
Corrective maintenance: This is a maintenance strategy that involves every activity performed to identify, detect and rectify a fault so that the failed structure or building element can be restored to its normal state. This type of maintenance is carried out in other to restore the structure to its original state. If this type of maintenance is to be used, then the element is allowed to be used until it breaks down to a point where it can only be repaired or replaced. Preventive maintenance: This is another type of maintenance that is performed on a building structure to lessen the likelihood of it failing. Just as the name implies, it is performed immediately it is detected to avoid an unexpected collapse. Condition based maintenance: This strategy involves maintenance when the need arises. It involves the use of actual condition of the structure to decide what maintenance needs to be done. This can be done by monitoring the buildings elements such as walls, floors, roof etc to identify which element that requires maintenance before a major failure occurs. Passing and Signing the National Building Code
The national building code is the document that is expected to regulate the conduct and operations of professionals and stakeholders in the construction industry. It is some sort of guideline for those who operate in the building/environment sector. Experts believes the absence of a National Building Code has been largely responsible for the incessant incidence of collapsed buildings being witnessed across the country and that passing the national building code into law will definitely;
Regulate and stop the use of non-professionals and quacks in the building and construction industries who are also major contributors of building collapse. Ensure the compliance by contractors to stop the use of untested products and materials in all construction projects as a way of preventing structural defects. Proper maintenance culture. Just as I stated earlier that poor maintenance culture can lead to building collapse. The national building code will ensure that builders implement good maintenance culture regularly and always.
Conclusion
Apart from some very rare cases of the act of God, most building collapse cases in Nigeria are majorly man-made. By following these 5 solutions, I can guarantee to a very large extent that the numbers of building collapse cases in Nigeria will drastically reduce if not totally eradicated.
Obviously, these are not all the guaranteed solutions to building collapse in Nigeria, as I continue my research and study on this subject matter, be rest assured to get more updates from me!
