Volume 3, Issue 3 (September 1980)
Effect of Stress Concentrations on the Cyclic Behavior of Sands
A laboratory study is presented on the effect of rigid inclusions on the observed cyclic strength of sand specimens. The test program consisted of 20 cyclic triaxial strength tests. Sixteen of these tests were conducted on specimens that had a spherical cemented sand inclusion of varying diameter located in either the middle or upper third of the specimen. The remaining four specimens were homogeneous. Results indicated that the cyclic strength of a specimen with an inclusion was increased up to a maximum of 6 to 7% over that of a corresponding homogeneous specimen at an area ratio (area of inclusion/area of specimen) of 10%. An increase in the area ratio to 25% showed a decrease in cyclic strength to a level similar to that exhibited by a homogeneous specimen. In addition, for a constant area ratio the increase in cyclic strength was shown to be greatest for a low stress ratio.