Abstract
The mechanical behaviour and material constants of in-situ compacted rock materials under high overburden pressure have been investigated based on the field measurements, laboratory tests, and computational analysis. By analyzing the actual settlements of rock zone during construction of several large-scaled fill dams and laboratory compression tests for rock materials, the elasto-plastic deformation of rock materials under high overburden pressures have been found to exist. Several factors affecting the compressibility of rock materials; mean grain size, grain size distribution, and void ratio have been investigated by detailed analysis of field measurements of several fill dams. As a result, a tentative procedure of estimating the material constants of in-situ rock zones based on the laboratory tests is suggested. Stress-deformation analysis of an actual rockfill dam during constructionand first res-oivor fillin g process by an elasto-plastic finite element method, using the constitutive equation by Sekiguchi and Ohta is canrried out. Good agreements between calculated and measured deformations and earth pressures are obtained.
