In the recent years some spectacular failures have happen in the world, which may be related directly or indirectly to errors committed by structural engineers. Building failure occurs when the building loses its ability to perform its intended design function. Hence, building failures can be categorized into the two broad groups of physical (structural) failures which result in the loss of certain characteristics and performance failures which means a reduction in function below an established acceptable limit. Figure 1 shows the picture of building and bridge collapse.
Experience and judgment, which play an essential position in structural design, acquire little interest in technical literature. Technical literature concern about the failures of the past is rare. Usually engineers do not want to speak about their mistakes in structural failures. Actually full discussion of failures can be useful, as it shows of awesome achievements or improvement. For the structural failures can be caused by unsatisfactory material, erection or fabrication errors, faulty design. Frequent causes of structural failures are foundations movements, connections fail, incorrect appraisal of the buckling strength, lack of adequate bracing, overloading and fatigue. Structural failures do not usually mean collapse.
Generally, the collapse or the rupture of the structure may additionally happen when:
ü some of the principal structural members or connections fail
ü as a result of fatigue after a large number of alternating stresses.
ü buckling of the main members
ü severe blast or impact.
The computation of an isolated compression member with known condition of loading and support is relatively a simple problem when the element is considered as a whole, is difficult to establish the effectiveness of the stiffeners and bracings, the rigidity of the end supports, the load eccentricity etc. Overloading can occur as a result of changes in the use of the structures. For example, in the last decades, the traffic on bridges becomes heavier and denser. In these cases, an investigation of the existing structural safety is necessary. The experience from failure of different constructions provides a valuable knowledge base and gives an overview of the reliability of these structures.Examples of structural failures and collapses around the world such as Hyatt Regency Hotel Walkway Collapse (1981), I-35W Bridge Collapse (1967), Savar Building Collapse (2013) and etc.