Volume 29, Issue 5 (September 2006)
Large-scale Apparatus for Monotonic and Cyclic Soil-Structure Interface Test
A large-scale direct shear test apparatus was developed to investigate the monotonic and cyclic behavior of a soil-structure interface. The apparatus provides a constant sample size 50 cm in length and 36 cm in width. Three kinds of normal boundary conditions, namely, constant normal stress, constant normal stiffness, and constant normal displacement, can be directly applied on the interface with high accuracy. The apparatus is equipped with an automated loading system with capacity up to 200 kN in both directions. The stress and displacement of the interface can be automatically measured with the apparatus. In addition, the movement and crushing of soil particles near the structure can be observed and recorded. Therefore, this apparatus is suitable for monotonic and cyclic tests of the interface between structure and gravelly soil. The effectiveness of this apparatus was confirmed by tests of the interface between structure and gravel. The test results show that the steel-gravel interface exhibits significant change in the physical state and volumetric strain due to shear application.