structures must be proportioned so that they will not fail or deform excessively under the loads they may be subjected to over their expected life. Therefore, it is critical that the nature and magnitude of the loads they may experience be accurately defined. Usually there are a number of different loads, and the question as to which loads may occur simultaneously needs to be addressed when specifying the design loading. In general, the structural engineer works with codes, which specify design loadings for various types of structures. General building codes such as the “International Building Code” specify the requirements of governmental agencies for minimum design loads for structures and minimum standards for construction. Professional technical societies such as the American Society of Civil Engineers (ASCE) , the American Concrete Institute (ACI) , the American Institute of Steel construction (AISC) , and the British Standards Institute (BSI) publish detailed technical standards that are also used to establish design loads and structural performance requirements.