This report contains the findings of a study to develop resistance factors for driven pile and drilled shaft foundations These factors are recommended for inclusion in Section 10 of the AASHTO Load and Resistance Factor Design (LRFD) Bridge Design Specifications to reflect current best practice in geotechnical design and construction The report also provides a detailed procedure for calibrating deep foundation resistance The material in this report will be of immediate interest to bridge engineers and geotechnical engineers involved in the design of pile and drilled shaft foundations

Load and resistance factor design (lrfd) for deep foundations

A discussion of a paper with the aforementioned title by Murff and Hamilton, published in this journal (Volume 119, Number 1, January 1993), is presented The discussion focuses on laterally loaded piles in layered soils Maugeri, Castelli, and Motta assert that the authors' method overpredicts the ultimate lateral resistance on the pile Discussion is followed by closure from the authors

P-ultimate for undrained analysis of laterally loaded piles. discussion and closure

The development of a generalised framework for assessing bridge life-cycle performance and cost, with emphasis on analysis, prediction, optimisation and decision-making under uncertainty, is briefly addressed. The central issue underlying the importance of the life-cycle approach to bridge engineering is the need for a rational basis for making informed decisions regarding design, construction, inspection, monitoring, maintenance, repair, rehabilitation, replacement and management of bridges under uncertainty which is carried out by using multi-objective optimisation procedures that balance conflicting criteria such as performance and cost. A number of significant developments are summarised, including time-variant reliability, risk, resilience, and sustainability of bridges, bridge transportation networks and interdependent infrastructure systems. Furthermore, the effects of climate change on the probabilistic life-cycle performance assessment of highway bridges are addressed. Moreover, integrati...

Bridge life-cycle performance and cost: analysis, prediction, optimisation and decision-making

Cross-wind modal properties of offshore wind turbines identified by full scale testing

An extensive program of laboratory model tests was undertaken to study the effect of slope and loading direction on laterally loaded piles in cohesionless soil. The paper includes studies of the effect of distance from the crest of the slope (both slope side and embankment side), soil properties, and loading direction (both forward in the direction of the slope and reverse loading). The pile lateral capacity in sloping ground was compared with that in horizontal ground. From the experimental investigation, it is observed that when piles installed in sloping ground undergo forward loading, lateral capacities of the piles are almost reached at 8% of the pile diameter in loose-to-medium dense soil and 16% of the pile diameter in dense soil. If the pile is placed >15 times the pile diameter away from the slope crest within the embankment, the influence of slope in the lateral-load capacity is almost negligible under both forward and reverse lateral load.

Effect of Slope and Loading Direction on Laterally Loaded Piles in Cohesionless Soil

Several methods are available for predicting the ultimate lateral resistance to piles in cohesionless soils. However, these methods often produce significantly different ultimate resistance values. This makes it difficult for practicing engineers 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, a simple method is proposed for calculating the ultimate lateral resistance (including frontal soil resistance and side shear resistance) to piles in cohesionless soils. The calculated ultimate lateral resistance from the proposed method agrees well with that obtained from centrifugal tests of flexible model piles. Predicting the lateral load capacity of laboratory and field rigid test piles in cohesionless soils using the proposed method also yields satisfactory results.

Ultimate Lateral Resistance to Piles in Cohesionless Soils

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

Ultimate resistance of laterally loaded piles in cohesionless soils

The authors acknowledge and thank the discusser for the contribution of the Rutledge nomograph and using it to obtain the lateral resistance distribution found in Prasad and Chari (1999) They note, too, that such a contribution is a great help to the entire geotechnical profession in that it offers perspective and avoids 'reinventing the wheel'

Ralph Grismala

Papers

Ultimate Lateral Resistance to Piles in Cohesionless Soils

Ultimate resistance of laterally loaded piles in cohesionless soils

Closure to “Ultimate Lateral Resistance to Piles in Cohesionless Soils” by Lianyang Zhang, Francisco Silva, and Ralph Grismala