Building collapses,sign of structural defects that caused by structural movements.

 

                                   Building collapse in China.

  
Tacoma Narrows Bridge Collapse in the U.S state of Washington.

      Bridge Collapses into the Mississippi river in United State.

Reasons Structures Fail

Defective construction that causes failure may be due to numerous reasons that may not be easy to predict before or during the construction. The major causes of structural failure are defective designs that have not determined the actual loading conditions on the structural elements. Inferior construction materials may also be the cause since the loads are calculated for materials of specific characteristics. Structure may fail even if the design is satisfactory, but the materials are not able to withstand the loads. Employment of unskilled labor on construction work is another reason for structural failures. Therefore, it is important that the owners, designers, and builders are fully conscious of the reasons of failure, and undertake all preventive measures.

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WHAT IS STRUCTURAL MOVEMENT?

Subsidence, settlement, heave, sway, bouncy floors, bulging walls, cracks, expansion and contraction are all forms of structural movement. Such movement occurs all the time, and usually its magnitude is so small it passes unnoticed. Only when distortions and cracks threaten the use or safety of the structure need we be concerned.

Brickwall structural movement.

Wall structural movement.

Major structural movement of Victorian Houses.

WHAT CAUSES STRUCTURAL MOVEMENT?

New structures are designed to carry their own weight and imposed loads so that strains are kept within reasonable limits; safety factors are included to cater for variations in quality of materials, design and construction inaccuracies, and random or accidental forces. In historic structures detrimental movement results from inadequate design and construction, decay and ill-considered alterations.