CYCLONE RESISTANT LOW COST HOUSING IN COASTAL AREA OF BANGLADESH

The coastal zone of Bangladesh has been facing wind related natural disasters like sidr, tornado, cyclone etc every year. These disasters cause large scale damages to socioeconomic condition, destructions of infrastructures-residents and death, injuries to human and animals. The main reason is non-engineered houses constructed by the local people due to lack of technical guidance and affordability. Considering the growth of non engineered housing, and the damage level of housing due to past wind induced disasters, it became essential to develop an appropriate wind resistant housing model for safe shelter and minimizing the losses of lives and economy. The aim of this study is to investigate the present housing condition in southern part of Bangladesh to develop and establish a comprehensive, safe and economical design concept, so that people under poverty can build structurally robust house to resist high speed wind within their affordable limit. In preliminary of dissertation, present housing patterns and extreme wind speed faced in southern part of the country are surveyed. The models of existing houses are made (reduce scale) using survey data for laboratory test to investigate ultimate wind load capacity and failure mode of existing house. The same model is then strengthened by bracing in the roof truss and cross bracing in the wood wall. Both experimental study using UTM and numerical study by computer program SAP2000 has performed for existing and proposed housing model basis on the concept of suction force acting on roof during wind action. It was found most of them are failed by joint failure and wind resistance of such existing houses increase about 40%-50 % when tie and bracing strengthening technique is applied.