Experimental investigation of traditional Kath-Kuni wall system and traditional joints

Abstract

In the Indian Himalayan region, the traditional vernacular construction system is a centuries-old system that is considered a seismic-resistant construction system. This practice is developed in the area over a period of time by the local communities and is never conventionally engineered. Hence, it is important to know about the behaviour of traditional construction systems and key features associated, under gravitational and lateral loading conditions. In the present research, experimental studies have been done on the full scale as well as scaled-down kath-kuni wall specimens, under push-over loading conditions, to characterize its overall behaviour, deformation and earthquake-resisting features. The failure of the kath-kuni wall was governed by friction capacity reduction followed by internal rotation in wooden layers. The kath-kuni system showed high ductile behaviour and the behaviour factor R was calculated as more than 5.4, and was compared with conventional brick masonry. The joints in the kath-kuni wall system have been identified and separate experimental studies, with varying member sizes, have been conducted to find out behaviour and capacity of these traditional joints upon loading. Analytical equations, to calculate capacity, have been proposed and compared with experimental results. The coefficient of friction was found to be varying in between 0.42–0.8 for different surfaces under constant overburden.