ISSN: 1945-7545
CODEN: GTJODJ
Page Count: 7

Changes in Interface Stresses During Pullout Tests on Geogrid Strip Reinforcement

Hayashi, S
Professor, guest associate professor, and former graduate student, Institute of Lowland Technology, Saga University, Saga,

Shahu, JT
Professor, guest associate professor, and former graduate student, Institute of Lowland Technology, Saga University, Saga,

Watanabe, K
Professor, guest associate professor, and former graduate student, Institute of Lowland Technology, Saga University, Saga,

(Received 25 September 1997; accepted 25 September 1998)

Abstract

For a strip geogrid reinforcement, pullout resistance per unit width is known to increase with decreasing specimen width at low applied normal stresses. This phenomenon can be explained by a conceptualized model for a pullout interaction mechanism consisting of combined 2-D and 3-D interaction mechanisms, and the results obtained from laboratory pullout tests can be extended to the field. In this paper, a series of pullout tests on stiff extruded geogrid specimens embedded in dense sandy gravel was carried out and the normal stresses at the soil-reinforcement interface were measured by small-diameter earth pressure cells. On the basis of these tests, the fundamental behavior of soil-geogrid reinforcement interaction is explained and the conceptualized pullout interaction model is corroborated. It is shown that restrained positive dilatancy, observed at low applied normal stresses, results in an increase in actual normal stresses at the soil-reinforcement interface at the edges of the geogrid, thereby increasing the pullout resistance of the reinforcement.

Keywords:
dilatancy, earth pressure, geogrid, laboratory pullout tests, stress measurement

Paper ID: GTJ11314J
DOI: 10.1520/GTJ11314J
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