Investigation of Critical Depth of Liquefaction in Soil Deposits Containing Double Loose Sand Lenses

Seismic stability is a major concern for geotechnical engineers. Due to the high destruction potential of liquefaction, the prediction of this phenomenon is of significant importance. Reducing soil strength dramatically, liquefaction usually produces large deformations and severe damages. In many regions, despite good geotechnical characteristics of soil deposits, large settlements due to liquefaction have been observed. These deposits often contain some sedimentary layers of loose sand surrounded by clayey or silty soils. This paper aims at investigating the liquefaction mechanism of double sand lenses using finite difference method in plane strain condition. The computer code, "FLAC 4" has been used for modeling. Deformations due to dynamic loading have been investigated. The critical depth is strongly dependent on the size of the loose sand lenses. The critical depth increases with the increasing of the magnitude of acceleration.