Behaviour of saturated railway track foundation materials during undrained cyclic loading

• Published in: Canadian geotechnical journal 2018-05, Vol.55 (5), p.689-697
• Main Authors: Mamou, Anna, Priest, Jeffrey A, Clayton, Christopher R.I, Powrie, William
• Format: Article
• Language: English
• Subjects: appareils à cylindre creux; argile; Axial strain; Building foundations; Clay; Cyclic loading; Cyclic loads; cyclic tests; Cylinders; Dynamic testing (Engineering); essais cycliques; excess pore pressure; global void ratio; hollow cylinder apparatus; intergranular void ratio; limon; Mechanical properties; Methods; Pore pressure; Pores; Porosity; pression de pores excessive; Pressure; principal stress rotation; Railroad tracks; Railway tracks; rapport de vide global; rapport de vide intergranulaire; Rotation; rotation de contrainte principale; sable; sand; Shear stress; silt; Testing; Void ratio; Weight
• ISSN: 0008-3674; 1208-6010
• DOI: 10.1139/cgj-2017-0196

This paper presents results of a series of hollow cylinder tests carried out to investigate the undrained behaviour of saturated railway track foundation materials during cyclic loading involving principal stress rotation. Four sand–clay mixes representative of real railway track foundation materials were investigated. It was found that moderate additions of clay (up to ∼14% by weight) increased the cyclic shear stress threshold at which significant excess pore pressures started to accumulate. After the cyclic shear stress threshold had been exceeded, the rate of pore pressure increase with the logarithm of axial strain was greatest for the material having a clay content of 11%. Excess pore pressure generation reduced with increasing intergranular and global void ratio, with the global void ratio being perhaps the more useful indicator because of the reduced amount of scatter and higher correlation of the idealized relationship.