Effects of Principal Stress Rotation on Permanent Deformation in Rail Track Foundations

A realistic assessment of the whole life cost of rail track foundations requires analysis of the effects of the repeated loadings applied by trains. This paper reports the effects of principal stress rotation (PSR) during cyclic loading on the permanent deformations measured in a series of hollow cylinder tests. The tests were carried out on a number of reconstituted soils selected in order to simulate foundation materials on an existing heavy haul railway line. Typical loadings and track geometry together with dynamic finite-element analyses were used to define representative stress changes to be applied to these soils, which were then tested with and without principal stress rotation during loading. It is shown that principal stress rotation has a significant and deleterious impact on permanent deformation of some materials. Therefore, it is concluded that cyclic triaxial testing, which cannot impose principal stress rotation, will not necessarily give good estimates of the long-term performance of rail track foundations. As PSR cannot be ignored when evaluating permanent displacements of rail track foundations, the use of more appropriate (realistic) testing methods such as the cyclic hollow cylinder or the cyclic simple shear apparatus is required.

[1]  T. Leslie Youd,et al.  Compaction of Sands by Repeated Shear Straining , 1972 .

[2]  A. W. Bishop,et al.  A hydraulic triaxial apparatus for controlled stress path testing , 1975 .

[3]  J. T. Shahu,et al.  A simple test methodology for soils under transportation routes , 1999 .

[4]  S F Brown,et al.  A CYCLIC SIMPLE SHEAR APPARATUS FOR DRY GRANULAR MATERIALS , 1978 .

[5]  Antonio Gens,et al.  Drained principal stress rotation in saturated sand , 1988 .

[6]  J. R. F. Arthur,et al.  Sand sheared by stresses with cyclic variations in direction , 1986 .

[7]  C.R.I. Clayton,et al.  Permanent deformation of railway foundations under heavy axle loading , 2003 .

[8]  Ronald F. Scott,et al.  Principles of soil mechanics , 1963 .

[9]  D. W. Hight,et al.  A SIMPLE PIEZOMETER PROBE FOR THE ROUTINE MEASUREMENT OF PORE PRESSURE IN TRIAXIAL TESTS ON SATURATED SOILS , 1982 .

[10]  Lidija Zdravković,et al.  The effect on anisotropy of rotating the principal stress axes during consolidation , 2001 .

[11]  J. T. Shahu,et al.  A RATIONAL METHOD FOR DESIGN OF RAILROAD TRACK FOUNDATION , 2000 .

[12]  A. Bishop,et al.  Measurement of Soil Properties in the Triaxial Test , 1976 .

[13]  As Saada.  State-of-the-Art Paper: Hollow Cylinder Torsional Devices: Their Advantages and Limitations , 1988 .

[14]  Fumio Tatsuoka,et al.  Failure and Deformation of Sand in Torsional Shear , 1986 .

[15]  Antonio Gens,et al.  Undrained anisotropy and principal stress rotation in saturated sand , 1984 .

[16]  Ching S. Chang,et al.  Soil Failure Modes in Undrained Cyclic Loading , 1981 .

[17]  Marshall L. Silver,et al.  Advanced Triaxial Testing of Soil and Rock , 1988 .

[18]  Gualtiero Baldi,et al.  A reevaluation of conventional triaxial test methods , 1988 .

[19]  Pc Knodel,et al.  Corrections for Membrane Strength in the Triaxial Test , 1990 .

[20]  Richard J. Jardine,et al.  Shear strength anisotropy of natural London Clay , 2007 .

[21]  Alec Westley Skempton,et al.  The Colloidal “Activity” of Clays , 1984 .

[22]  F. Molenkamp,et al.  Modelling and minimization of membrane penetration effects in tests on granular soils , 1981 .

[23]  地盤工学会.  Standards of Japanese Geotechnical Society for laboratory shear test , 2000 .

[24]  Antonio Gens,et al.  THE DEVELOPMENT OF A NEW HOLLOW CYLINDER APPARATUS FOR INVESTIGATING THE EFFECTS OF PRINCIPAL STRESS ROTATION IN SOILS , 1983 .