Investigation of cracks developed in Dematamal Viharaya, Buttala

Abstract

Dematamal Viharaya of Buttala is one of the oldest Stupas in Sri Lanka built in the 2nd Century BC. It is a !8m tall non-plastered brick structure. This Stupa has developed some cracks in the recent past. Cracks have initiated from the Pesawalalu to the top of the Dome, The research covered in this paper was aimed at the identification of the causes for the cracks and to propose corrective actions. A comprehensive study was carried out to identify' the possible causes for the cracks which may be due to settlement of the foundation, expansive nature of soil, self weight of structure or the separation of the old and new parts of the Stupa. Tests were done to assess the expansive nature of the soil and a detailed analysis was carried out using SAP2000 to test the other two hypotheses. The results revealed that the possible cause could be the contraction of the old brick work beneath the new brick work and the discontinuity between them. Based on the identified causes corrective actions have been proposed.