Abstract: The weathered granites in the eastern foothills of Lüliang Mountain are significantly different from those occurring in the southern China, Japan and South Korea. To understand comprehensively the physical and mechanical properties of the compacted weathered granite in Lüliang Mountain, a series of laboratory tests including routine soil test, X-ray diffraction test, large consolidation test, large-scale triaxial test and so on is performed to analyze the compaction, load-bearing, deformation, dilatancy and strength characteristics of strongly weathered granite. The experimental results show that the clay content has a remarkable influence on the compaction characteristics of compacted weathered granite and the load-bearing characteristics, and there exist two threshold values of clay content, when the clay content is about 8%, the dry density of the sample reach the maximum, while about 4%, California bearing ratio(CBR) has a maximun value. The soil samples in this study have no expansion potential and their compressibility are generally low. Two salient phenomena of plastic deformation can be observed on the secondary loading and unloading compression curve due to particle breakage of compacted weathered granite. Because the soil particles might undergo compacted, dislocated, overturned or crushed processes, the soil samples show different dilatancy characteristics under different confining pressures. In addition, due to the existence of particle breakage, the strength of sample exhibits nonlinear characteristics.

Key words: compacted weathered granite soil, dilatancy, strength, large consolidation test, large-scale triaxial test