Numerical Simulations of Pullout Characteristics and a Calculation Method for Ultimate Pullout Resistance of Denti-Geogrids

Aiming at a new geotechnical reinforcing material—denti-geogrids, pullout tests were simulated by numerical simulations. The accuracy for calculation results of the ultimate pullout resistance for denti-geogrids with a single transverse rib by the flow-around model, Peterson-Anderson model, Jewell model, Chai model and Rankine model, as well as the numerical analysis model were comparatively researched. And the friction characteristics of the interfaces were studied and the formula for the ultimate pullout resistance of denti-geogrids with multi-ribs was put forward on the basis of factor analysis. Researches showed that: 1) For denti-geogrid with a single transverse rib, the ultimate pullout resistance calculated by Jewell model was closest to the numerical simulation result (with an average error of 5.35%), the Rankine model was relatively simple and precise for engineering application. 2) In the same test conditions, the pullout resistance of denti-geogrids was much higher than that of common geogrids. Also, the interface cohesion, friction angles, pullout coefficients, and apparent friction coefficients of denti-geogrids at all levels of normal stress were larger. 3) For denti-geogrids with multi-ribs, the relations for the ultimate pullout resistance between the detni-geogrid rib quantities, spacing and normal stress were separately exponential, logarithmic and linear. The ultimate pullout resistance for denti-geogrids with multi-ribs in different working conditions was calculated by the suggested formula, and the reliability was verified.