Cracking similarity simulation of induced joints and its application in model test of a RCC arch dam

Abstract

Similarity simulation of induced joints is a key technical problem arising from failure mechanism study of Roller Compacted Concrete (RCC) arch dams with induced joints by using physical model test. This paper proposes an original fracture mechanics-based method for simulating induced joints in physical model test and presents results obtained from model test of Shapai RCC arch dam in Sichuan Province, China. Test was performed to obtain values of fracture toughness of prototype (RCC) and model (gypsum) materials. The relation between fracture toughness and stress intensity factor of induced joint was analyzed, and crack propagation condition and physical model simulation method of induced joint were proposed. The proposed induced-joint simulation method was applied in the model test of Shapai arch dam; the anticipated effect of induced joints to reduce tensile stress was confirmed and the cracking process, the failure pattern and mechanism of Shapai RCC arch dam were obtained. These results provided valuable data for the engineering design and construction of Shapai RCC arch dam, which survived Wenchuan Earthquake of May 12, 2008 without suffering any damage. Its sound performance resulted directly from the well-thought design, which greatly benefited from these comprehensive investigations.