Managing Director, Nuttall Geotechnical Services Ltd., Colnbrook, Bucks
Pages: 23 Published: Jan 1973
The peak strengths of sand in symmetric strain (for example, triaxial compression) and plane strain converge at very loose densities towards the common ultimate strength. By dividing the peak strengths by the constant ultimate strength, a set of dimensionless curves is obtained which represent the extra strength that can be mobilized in sand at relative densities above zero. For the range of ultimate strengths normally encountered in natural sands (φcv = 28 to 36 deg), computations show that these extra strengths can be represented by single curves of density components φdc (in degrees) which can be added to the ultimate strength to give the total drained strength, φd. The ultimate strength φcv can be reliably estimated by performing a static angle of repose test on the sand. The recommended techniques for measuring the angle of repose and the maximum/minimum density of sand in the laboratory are described. The method of predicting strengths has been compared with actual strength tests performed on several sands of diverse origins, and the comparisons generally agree to within 1 deg on average. Finally, typical computations are presented to aid the practicing engineer in the use of the method.
density (mass/volume), sands, angle of repose, triaxial stresses, shear strength, tests, cohesionless soils
Paper ID: STP37878S