粗粒材料の動的変形特性について

Abstract

Although a great deal of coarse graveley materials such as crushed rocks and round gravels are widely utilized in the construction of rockfill dams and often encountered as foundation materials, informations on their dynamic properties are far less available as compared to finer materials like clay, silt and sand, mainly because the maximum particle size (Dmax) should be restricted in the laboratory to hold a certain accuracy of test results. In the present paper, dynamic deformation characteristics of graveley materials are investigated through a series of cyclic triaxial tests on specimens prepared in four similar gradations by varying the maximum size of particles. Concluding remarks are summarized as follows : (1) the modulus of rigidity (G) of crushed rocks increases proportionally with the increase in the maximum particle size (Dmax) in log-scale plotting. an experimental formula is proposed to evaluate the modulus value in the field for real construction materials. (2) the reference strain (γ_r) is hardly influenced by the value of Dmax, having a constant value in the range ofDmax>9.52mm. (3) damping factor (h) shows a slight increase with the increase in Dmax. (4) dynamic deformation properties of crushed rocks are considerably influenced by the size of specimens in the test.