ABSTRACT
However, for what concerns structural safety, risk mitigation is not only a matter of material. No material is anti-seismic itself: safety is rather an attribute belonging to a certain building in a certain context. Shape, techniques, detailing and non-predominant materials and components may dramatically change the structural behaviour of a masonry building. In many instances, traditional
1 INTRODUCTION
It was calculated that today about one third of mankind dwells or works in earthen buildings (Dethier 1982, Oliver 1983), mostly in underdeveloped countries even if this kind of constructions are widespread all over the globe in form of rural and poor settlements (Oliver 2003) as well as historic monumental heritage (UNESCO 1982) and contemporary innovative architectures (Minke 2006). In less industrialised contexts the use of traditional materials and labour-based processes is a necessity rather than a choice and the result are vernacular non-engineered structures built without the supervision of a trained architect or engineer. Such aspects add further vulnerabilities to the already low structural performances of the soil and make the buildings more exposed to natural hazards, in particular to earthquakes that repeatedly strike regions where earthen architecture is diffused. Considering the number of inhabitants involved all over the planet and the unlikeliness for this situation to change soon, it is then urgent to research on faisable strengthening systems for earthen constructions instead of promoting a sudden and utopic replacement of this building stock with a “modern” one. Beside, earthen buildings present a number of advantages in terms of sustainability, with reference to its social, economic and ecologic meaning and recent trends in construction already changed to prefer natural and non-toxic materials to build healthy environments. Local building techniques evolved over the centuries and optimized the
constructive cultures developed strategies against earthquakes, using materials and products related to their lands, frequently including raw earth masonry and wood (Omar Sidik 2013).
