Undrained Compression Behavior of Sand

Abstract

To support a theory proposed to explain the mechanism causing blast‐induced liquefaction, a series of high pressure undrained isotropic compression tests have been performed on Monterey No. 0 and Eniwetok sands. These tests show that sand can be liquefied (in the sense of 100% pore pressure rise) by a single cycle of isotropic compressive stress applied under quasistatic, undrained conditions. Eniwetok sand was found to be much easier to liquefy than Monterey sand. Initial dry density was not a significant factor in the generation of residual excess pore pressure for either sand. Drained isotropic compression tests and membrane penetration tests were also performed on the sands. These tests were used to determine the magnitude of system compliance and to allow calculations of predicted undrained behavior based on drained material properties. System compliance was shown to inhibit the development of liquefaction. Predicted undrained behavior compared favorably with test results, although additional work is needed. A series of grain crushing experiments show that Eniwetok sand crushes more easily than Monterey sand. This may account for the difference in pore pressure response.