Ultimate Resistance of Laterally Loaded Piles in Cohesionless Soils

Abstract

A key element in the design of laterally loaded piles is the determination of the ultimate resistance that can be exerted by the soil against the pile. Several methods have been published for predicting the ultimate resistance of laterally loaded piles in cohesionless soils. However, these methods often produce significantly different ultimate resistance values. This makes it difficult for practical designers to effectively select the appropriate method when designing laterally loaded piles in cohesionless soils. By analyzing the lateral soil resistance distribution along the width of the pile and based on the test results of model rigid piles in cohesionless soils collected from the published literature, an expression is developed for the ultimate resistance (including frontal soil resistance and side shear resistance) of laterally loaded piles in cohesionless soils. Application of the developed expression to predict the lateral load capacity of laboratory and field rigid test piles in cohesionless soils gives satisfactory results. Introduction Piles have been used extensively for supporting axial and lateral loads for a variety of structures including heavy buildings, transmission lines, power stations, and highway structures. Lateral loads govern the design of piles in many cases. A key element in the design of laterally loaded piles is the determination of the ultimate resistance that can be exerted by the soil against the pile. Several methods have been published for predicting the ultimate resistance of laterally loaded piles in cohesionless soils (Brinch Hansen 1961; Broms 1964; Reese et al. 1974; Poulos and Davis 1980; Fleming et al. 1992). However, these methods often produce significantly different ultimate resistance values. This makes it difficult for practical designers to effectively select the appropriate method when designing laterally loaded piles in cohesionless soils. Because the problem of finding the ultimate resistance for a laterally loaded pile is three dimensional and nonlinear, finding a rigorous analytical solution is highly unlikely and finding a rigorous numerical solution is expensive. So the existing solutions for the ultimate resistance are either of a semiempirical nature or employ approximate analysis which often involves considerable simplifications (Jamiolkowski and Garassino 1977). This may be the reason why different methods often produce significantly different ultimate resistance values. * Consultant, Arthur D. Little, Inc., Acorn Park, Cambridge, MA 02140; PH 617-498-6348; zhang.lianyang@adlittle.com ** Director and VP, Arthur D. Little, Inc., Acorn Park, Cambridge, MA 02140; PH 617-498-5850; silvatulla@adlittle.com *** Principal, Arthur D. Little, Inc., Acorn Park, Cambridge, MA 02140; PH 617-498-5449; grismala.r@adlittle.com