Uncertainties of Field Pullout Resistance of Soil Nails
Publication: Journal of Geotechnical and Geoenvironmental Engineering
Volume 135, Issue 7
Abstract
A large number of field pullout tests on soil nails have been carried out to provide valuable information for enhancing the understanding of pullout resistance of soil-grout interface and for reliability evaluation of soil-nailed slopes. In this paper, a data set of 167 field pullout tests performed in 23 nailed completely decomposed granite cut slopes is used for a statistical evaluation of four factors influencing the pullout resistance of soil nails, namely overburden pressure, grout length, soil suction, and soil dilatancy. For the tests in which nails were pulled out, the measured pullout resistance is essentially independent of the effective overburden pressure. A bias factor is defined as the ratio of the measured pullout resistance and the calculated value using a design equation. The mean value of is 4.30 and the coefficient of variation is 47%. When the uncertainties in grout length, soil suctions around nails, and the soil shear dilatancy are considered, the mean value of can finally be reduced to 0.99. The quantification of the uncertainties provides a better physical understanding of the working mechanisms of soil nails.
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Acknowledgments
The work in this paper was substantially supported by the Research Grants Council (RGC) of the HKSAR, China (Project No. UNSPECIFIED620206), a joint program (Project No. NSFCN-HKUST611/03) between the RGC and the Natural Science Foundation of China (NSFC), the NSFC (Project No. NSFC50809038), the Shanghai Educational Development Foundation (Project No. NSFC2008CG17), and Shanghai Leading Academic Discipline Project (Project No. UNSPECIFIEDB208). This paper is published with the permission of the Head of the Geotechnical Engineering Office and the Director of Civil Engineering and Development, the Government of the Hong Kong Special Administrative Region.
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Information
Published In
Journal of Geotechnical and Geoenvironmental Engineering
Volume 135 • Issue 7 • July 2009
Pages: 966 - 972
Copyright
© 2009 ASCE.
History
Received: Apr 27, 2007
Accepted: Oct 20, 2008
Published online: Feb 20, 2009
Published in print: Jul 2009
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