期刊名称：Turkish Journal of Engineering and Environmental Sciences
印刷版ISSN：1300-0160
电子版ISSN：1303-6157
出版年度：2014
卷号：38
页码：382-391
DOI：10.3906/muh-1206-5
出版社：Scientific and Technical Research Council of Turkey
摘要：In most geotechnical projects the linear Mohr–Coulomb envelope is used. This envelope is curved for coarsegrained soils and is affected by some factors such as confining pressure, relative density, mineralogy, particle crushing, fine content, and gradation of sand particles. The curved strength envelope could be used to study the behavior of deep foundations, earth dams, soil slopes, and other earth structures in which failure occurs under considerable normal stresses. A deep failure surface may be more critical than a shallow surface when the phenomenon of curved strength envelopes is considered, because the secant friction angle decreases with increasing depth of soil layers and confining pressure. The main purpose of this research is to express the secant friction angle of sands as a function of normal stress and relative compaction. In this study, direct shear tests are performed on air-dried and saturated sand samples at different normal stresses to evaluate the variation of secant friction angle with these factors.
关键词：Dilatancy; secant friction angle; normal stress level; relative compaction
