Experimental Analysis of Traditional Kath-Kuni Wall System

In the Indian Himalayan region, a centuries old traditional vernacular construction and architecture method, known as Kath-kuni (also called: ‘cator-and-cribbage’ or ‘timber laced masonry’), well-known as a building style which is seismic resistant. This construction methodology is never conventionally engineered and it is essential to know about their performance under gravitational and seismic conditions. In this study experimental investigations were carried out on a scaled down wall model, built and tested at Indian Institute of Technology Roorkee. For the model, stones were replaced with the concrete bricks of M30 and deodar wood was used for wooden beams and joints. To this end, research, in-plane testing of wall to characterise its overall behaviour, deformations of wall and its components, ductility, testing of materials used, have been carried out. The wooden specimens were tested for their mechanical properties. The wall was loaded with an overburden of 0.045 MPa and subsequently a lateral load was applied in displacement increments. The failure of the wall was governed by internal rotation in the wooden layer and wall specimen showed a high ductility. The behaviour factor R of the tested wall is calculated to be 6.24 which comes out to be approximately 2.5 times higher than the values suggested for the regular masonry as per IS 1893. Most important seismic capacity features that contributed in ductility were found to be the wooden connections (kadil joints and maanwi joints). Since no adhesive was used in between wooden members they were allowed to rotate once the friction capacity in between wooden and stone layers exceeded.