An improved direct shear apparatus for sand

A conventional direct shear apparatus (DSA) has been modified to improve its articulation by moving the point of shear load application to the sample centre. Jewell's symmetrical arrangement has been adopted for a 100 mm square shearbox, resulting in increased dilation rate and reduced rotation. Testing using coarse Leighton Buzzard sand has enabled the performance of the modified DSA to be optimised by exploring different test configurations. Optimum results were obtained with a substantial initial gap between the shearbox frames of 5D50, the use of thin rubber edging strips to contain the sand, and the omission of grid plates at the sample boundaries. Upper-frame rotations persist during testing, but have almost no effect on measured parameters. A framework of relationships between parameters measured in a direct shear test ((ϕ′ds)p, ψp and (ϕ′ds)Id) and relevant plane strain parameters ((ϕ′ps)p and ϕ′crit) is set out, based on Rowe's flow rule and Davis's (1968) relation. Stroud's simple shear apparatu...

[1]  M. R. Dyer.  Observation of the stress distribution in crushed glass with applications to soil reinforcement , 1985 .

[2]  P. W. Rowe.  The Relationship Between the Shear Strength of Sands in Triaxial Compression, Plane Strain and Direct Shear , 1970 .

[3]  M. Bolton.  THE STRENGTH AND DILATANCY OF SANDS , 1986 .

[4]  Fumio Tatsuoka,et al.  STRENGTH AND DEFORMATION CHARACTERISTICS OF SAND IN TORSIONAL SIMPLE SHEAR , 1988 .

[5]  R. A. Jewell,et al.  DIRECT SHEAR TESTS ON SAND , 1989 .

[6]  Matthew S. Dietz,et al.  Developing an holistic understanding of interface friction using sands within the Direct Shear Apparatus , 2000 .

[7]  T. Mitachi,et al.  Interpretation of direct shear box testing of sands as quasi-simple shear , 1997 .

[8]  Seiichi Miura,et al.  A SAMPLE PREPARATION METHOD AND ITS EFFECT ON STATIC AND CYCLIC DEFORMATION-STRENGTH PROPERTIES OF SAND , 1982 .

[9]  M. Stroud,et al.  The behaviour of sand at low stress levels in the simple-shear apparatus , 1971 .

[10]  P. W. Rowe.  The stress-dilatancy relation for static equilibrium of an assembly of particles in contact , 1962, Proceedings of the Royal Society of London. Series A. Mathematical and Physical Sciences.

[11]  Kenichi Maeda,et al.  METHOD OF MEASUREMENT FOR THE ANGLE OF REPOSE OF SANDS , 1997 .

[12]  D. Potts,et al.  Finite element analysis of the direct shear box test , 1987 .

[13]  Static and cyclic direct shear tests on carbonate sands , 1992 .

[14]  R. A. Jewell,et al.  Direct shear tests on reinforced sand , 1987 .