Carlos Alberto Vega-Posada

Effect of Gas on the Mechanical Behavior of Medium-Dense Sands

AbstractThis paper presents the results of monotonic and cyclic triaxial tests performed on gassy, medium-dense sand specimens. These sands are representative of conditions in a loose-sand deposit that was densified using multiple blasting passes at a site in South Carolina. The equipment and laboratory testing procedures used to reproduce the postblast densification conditions observed at a field test are described in detail. Results of undrained and drained compression tests showed that the gassy-specimen responses were bounded by the fully saturated drained and undrained responses. The undrained test results showed that the presence of gas, even in small amounts, made the soil more compressible and restricted the buildup of excess pore-water pressures as compared with those pressures observed in fully saturated specimens. Additionally, the shear strengths of gassy, medium-dense sand specimens were similar to those observed in saturated, loose sands sheared under drained conditions. For a given cyclic s...

Blast densification: A proposed methodology to quantify the amount of densification required to prevent liquefaction and flow in sandy soils

This paper presents a methodology to quantify the amount of blast densification or number of passes required for a given project to prevent liquefaction and ...