Comparison of Various Methods for Determining
SourceA series of tests were conducted on sands to determine the value of the coefficient of earth pressure at rest (K0) and the factors which influence its magnitude. Four laboratory techniques were used to determine the value of K0 and the stress-strain relationship for Reid-Bedford sand at dense, medium, and loose states. Test results indicated that the value of K0 for the sand tested is not significantly influenced by the testing equipment or the technique used. Results show that K0 increases with decreasing relative density, increasing stress level, and number of loading cycles. On the first loading cycle, the value of K0 agreed well with Jaky equation K0 = 1 - sin φ. The constrained modulus D increased with increasing relative density, increasing stress level, and increasing number of loading cycles, but remained almost the same for all unloading cycles.