Location

San Diego, California

Session Start Date

5-24-2010

Session End Date

5-29-2010

Abstract

Soils most susceptible to liquefaction are loose, non-plastic and saturated. Because the compressibility of air is orders of magnitude greater than the compressibility of water, un-saturation or partial saturation can significantly increase the liquefaction resistance of a soil deposit. Nakazawa et al. (2004) have shown that cyclic strength in laboratory test specimens can be more than twice as high in partially saturated soil than fully saturated soil. It is hypothesized that sufficient de-saturation to increase the liquefaction resistance can be induced by injecting air or gas into the subsurface. Simple, qualitative shake-table experiments demonstrate the increase in liquefaction resistance as a result of de-saturation from air injection. Air sparging is a widely used environmental remediation method that involves the continuous injection of air into soil to promote volatilization of contaminants. This method can be readily adapted for use as a liquefaction mitigation technique. Although air sparging relies on a continuous flow of gas, Okamura et al. (2006) present data that indicate de-saturation from air injection can last for years or more after an initial, short-term injection period. In summary, intermittent or periodic air injection over the life of a structure may be useful in increasing the liquefaction resistance. This method would be particularly well suited for the protection of existing structures founded on soils susceptible to liquefaction.

Department(s)

Civil, Architectural and Environmental Engineering

Appears In

International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics

Meeting Name

Fifth Conference

Publisher

Missouri University of Science and Technology

Publication Date

5-24-2010

Document Version

Final Version

Rights

© 2010 Missouri University of Science and Technology, All rights reserved.

Document Type

Article - Conference proceedings

File Type

text

Language

English

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May 24th, 12:00 AM May 29th, 12:00 AM

Liquefaction Mitigation Using Air Injection

San Diego, California

Soils most susceptible to liquefaction are loose, non-plastic and saturated. Because the compressibility of air is orders of magnitude greater than the compressibility of water, un-saturation or partial saturation can significantly increase the liquefaction resistance of a soil deposit. Nakazawa et al. (2004) have shown that cyclic strength in laboratory test specimens can be more than twice as high in partially saturated soil than fully saturated soil. It is hypothesized that sufficient de-saturation to increase the liquefaction resistance can be induced by injecting air or gas into the subsurface. Simple, qualitative shake-table experiments demonstrate the increase in liquefaction resistance as a result of de-saturation from air injection. Air sparging is a widely used environmental remediation method that involves the continuous injection of air into soil to promote volatilization of contaminants. This method can be readily adapted for use as a liquefaction mitigation technique. Although air sparging relies on a continuous flow of gas, Okamura et al. (2006) present data that indicate de-saturation from air injection can last for years or more after an initial, short-term injection period. In summary, intermittent or periodic air injection over the life of a structure may be useful in increasing the liquefaction resistance. This method would be particularly well suited for the protection of existing structures founded on soils susceptible to liquefaction.