TOWARDS A SUSTAINABLE AND CONTEXT-BASED APPROACH TO ANTI-SEISMIC RETROFITTING TECHNIQUES FOR VERNACULAR ADOBE BUILDINGS IN COLOMBIA

In Colombia earthen buildings, mostly adobe, makes up 80% of the national monumental heritage and historic urban centres. Moreover, vernacular earthen techniques have been largely used for dwellings in rural villages, small towns or informal settlements and represent, nowadays, a huge architectural and cultural heritage of the country. Due the brittle behaviour and low ductility of the building material, characterized by both low tensile and bending strength, earth constructions show high seismic vulnerability; nevertheless, though Colombian earthquake hazard level is considered very high, current national seismic building regulations do not include any reference to earthen architecture. Seismic failure mechanisms most frequently occurring to masonry architecture, as adobe buildings rehabilitation techniques and seismic behaviour improvement practices, have been widely published. This paper aims to investigate possible causes associated to failure mechanisms due to common adobe building practices in Colombia and intervention strategies, to be eventually implemented in order to reduce risks. The paper focuses on strategies and technologies for seismic retrofitting, while evaluating their effectiveness and feasibility through ‘sustainability’ indicators, based on literature quantitative and qualitative data, and strictly related to rural Colombian economic, social and environmental conditions, where available resources are scarce and labour often not qualified.