The 1st International Symposium on Rockfill Dams STRENGTH EVALUATION OF ROCKFILL MATERIALS CONSIDERING CONFINING PRESSURE DEPENDENCY

Abstract: It is necessary to evaluate shear strength of rock materials, which are major construction materials for a rockfill dam, considering the confining pressure dependency for the rationalized design and seismic performance evaluation of this dam type. However, the triaxial compression test, which is the most common strength test for rockfill materials, has a problem in test precision under low confining pressure condition. In this study, we carry out large-scale triaxial compression tests under low confining pressure, large-scale box shear tests, and laboratory surface sliding tests for rock materials. Based on results of these tests, we investigate the evaluation method of the shear strength of rockfill materials under low confining pressure condition. In addition, we make a fundamental study on the setting method of the design strength of rock materials considering the confining pressure dependency. Key words: embankment dam, rockfill materials, design strength, confining pressure dependency