抄録
In evaluating liquefaction potential of saturated sandy deposits, it is necessary to estimate undrained cyclic shear strength of soils. On many occassions in actual design procedures, it is very convenient if engineers can evaluate undrained cyclic shear strength of sandy soils with use of ordinary engineering properties of soils and grounds such as grading properties of disturbed samples and blow counts (N-values) by standard penetration tests. For this purpose, available data of sand sampling, dynamic triaxial tests on undisturbed specimens, N-values by standard penetration tests and gradings were analysed and a correlation among dynamic shear strength, mean diameter D50 and Dγ*=21√(N/(συ'+0.7)), in which N is the blow counts by standard penetration tests and συ' is the in situ effective overburden pressure in kg/cm2, was obtained. This correlation is represented by a simplified equation. Using this equation, approximate dynamic shear strengths of reclaimed and alluvial sandy deposits can be easily estimated from N-values, συ' and D50.
