EVALUATION OF HYDRODYNAMIC FORCE ON SOLIDLY CONNECTED NATURAL STONE AND PROPOSAL OF ITS DESIGN METHOD

Abstract

In recent years, it has become necessary to develop suitable methods for restoring natural rivers. The authors have examined more nature-friendly hydraulic structures made of connected natural stones. Although such structures are excellent in environmental aspects, design standards for such structures have not been established yet because the structures comprise natural stones with various shapes. Furthermore, the design flow velocity is not clarified when the proposed connected natural stones were used as a groin and other hydraulic structures. At present, 1.2–1.5 times large velocity of the representative mean velocity is used as the design velocity. Therefore, in this study, the hydrodynamic force for solidly connected natural stones, and the velocity field around such structures were examined experimentally. Experimental results clarified not only the hydraulic characteristics of the flow around the groin, but also the drag and lift coefficients of the connected stone. An efficient design method for the solidly connected stone was proposed.