|
Abstract Applied with a large-scale direct shear apparatus，the 3D stress-controlled cyclic behavior of a gravel- structure interface was investigated and the influence of the shear path and stress amplitude was discussed. The tests were performed at normal stress of 400 kPa in two-way cross，one-way and two-way circular cyclic shear paths. Results indicate that：(1) The volumetric change of interface between coarse grained soil and structure can be divided into reversible and irreversible components in two-way cyclic shear paths. (2) Irreversible increment is dominant in the first few shear cycles，and then equivalent to reversible component which finally becomes the governing part of interface volumetric increment；but the volumetric change of interface gives priority to irreversible component. (3) Tangential displacement migrates with shear cycles. Interface exhibits non-coaxial behavior in the tangential direction for circular shear tests；tangential displacement amplitude and increment per shear stress decrease with shear cycles when the shear stress amplitude is relatively small. (4) With the increasing shear stress amplitude，non-coaxial angle decreases and tangential displacement and tangential displacement increment per shear stress both increase. Non-coaxial angle varies little with shear cycles in one-way circular shear path，while it has opposite algebraic sign at neighboring shear cycles in two-way circular shear path. (5) Tangential stress-tangential displacement curves present an elliptical shape in circular path and hyperbolic in cross shear path. Shear path and shear stress amplitude have notable influence on the 3D stress-controlled cyclic behaviors of interface.
|
|
Received: 27 April 2011
|
|
|
|
2011, Vol. 30 
