Deflection related serviceability issues in steel buildings with large span girders

Abstract

The usage of steel as a structural material has been gaining popularity in the recent years in Sri Lanka. Since the construction with reinforced concrete is of relatively lower cost in Sri Lanka, steel can become competitive only if special applications could be promoted. One such aspect is the speed of construction and another is the ability to span over larger distances due to light weight. However, such long spans create special serviceability related issues that would warrant special attention. One such issue occurs when masonry walls that are used as partitions are supported on the long span girders. In Sri Lanka, solid masonry wall partitions are considered as a need by the clients when they construct hotel buildings due to various issues that could arise with dry wall construction primarily due to the cost, hot humid environment and the durability issues. The weight of the masonry could give rise to greater deflection and hence could demonstrate a higher possibility for creating cracks. Another problem is the shrinkage related cracks that could be induced in the ends of the walls along with thermal related cracks when the masonry walls are exposed as in the case of external walls. All these cracks could be problematic for the structural engineer since all these cracks have to be repaired to ensure acceptable level of serviceability. Hence, various techniques that could be used to minimize the cracks in masonry either following the code based guidelines for deflection or devising special guidelines is a desirable approach that should be adopted by the structural design engineer. This research is aimed at identifying and solving such important issues that could otherwise impair the performance