Influence of rigidity on laterally loaded pile groups in marine clay
01 Jun 1998-Journal of Geotechnical and Geoenvironmental Engineering (American Society of Civil Engineers)-Vol. 124, Iss: 6, pp 542-549
TL;DR: In this article, the influence of parameters like flexural rigidity of pile material, embedment length of pile, and arrangement of piles with respect to the direction of loading on the behavior of laterally loaded pile groups has been studied through an experimental program.
Abstract: Pile-supported marine structures are designed for significant amounts of lateral load. In this paper, the influence of parameters like flexural rigidity of pile material, embedment length of pile, and arrangement of piles with respect to the direction of loading on the behavior of laterally loaded pile groups has been studied through an experimental program. The results obtained from lateral load tests carried out on model pile groups arranged at different spacings and embedded in a marine clayey bed are presented and discussed. The results indicate that the lateral load capacity of the pile group depends mainly on the rigidity of pile soil system for different arrangements of piles within a group. This is further substantiated by a simplified finite element analysis bringing in the differences in passive resistance. The group efficiencies under lateral loading obtained from the present investigation are found to be in good agreement with the predictions of earlier researchers.
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TL;DR: In this article, the results of static lateral load tests carried out on 1×2, 2×2, 1×4, and 3×3 model pile groups embedded in soft clay are presented.
Abstract: This paper presents the results of static lateral load tests carried out on 1×2 , 2×2 , 1×4 , and 3×3 model pile groups embedded in soft clay. Tests were carried out on piles with length to diameter ratios of 15, 30, and 40 and three to nine pile diameter spacing. The effects of pile spacing, number of piles, embedment length, and configuration on pile-group interaction were investigated. Group efficiency, critical spacing, and p multipliers were evaluated from the experimental study. The experimental results have been compared with those obtained from the program GROUP. It has been found that the lateral capacity of piles in 3×3 group at three diameter spacing is about 40% less than that of the single pile. Group interaction causes 20% increase in the maximum bending moment in piles of the groups with three diameter spacing in comparison to the single pile. Results indicate substantial difference in p multipliers of the corresponding rows of the linear and square pile groups. The predicted field group be...
104 citations
TL;DR: In this paper, 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, and it was 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% in dense soil.
Abstract: 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.
103 citations
Cites methods from "Influence of rigidity on laterally ..."
...The lateral load was applied until the lateral deflection reaches 20% of the pile diameter (5 mm) at just above the ground surface and the corresponding load was taken as the lateral-load capacity of the pile (Rao et al. 1998)....
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TL;DR: In this paper, a method of analysis for an off-ground cap supported by piles embedded in a layered soil and subjected to horizontal and vertical loads is presented, where the cap is modelled as a thin plate and the piles as elastic beams and the soil is treated as consisting of horizontal layers of different materials.
81 citations
TL;DR: In this article, the behavior of a single pile in sand under combined uplift and lateral load was investigated using physical scaling laws, based on adopted material properties of model and prototype pile foundations.
Abstract: 1-g model experiments were carried out in the laboratory to investigate the behavior of a single pile in sand under combined uplift and lateral load. Dimensions of the model pile were ascertained using physical scaling laws, based on adopted material properties of model and prototype pile foundations. The model pile is made up of aluminum and has outer and inner diameters of 25.4 and 19.0 mm, respectively. Different length-to-diameter ratios of 18, 28, and 38 are considered by varying the pile length to simulate behavior of both stiff and flexible piles. The test tank dimensions were chosen such that boundary effects are minimized. The size of the model steel tank is 1.0×1.0×1.2 m (depth). Experiments were performed on single piles embedded in sandy soil under independent uplift and lateral loading, and combined lateral and uplift loading. Results indicate that the load-deflection behavior is nonlinear for independent uplift and lateral load tests, as well as in the case of combined loading. It i...
67 citations
TL;DR: In this article, the effect of slope angle and relative density on bending moment, lateral soil resistance, lateral deflection and non-dimensional p-y curves for piles on sloping ground under surcharge load are developed modifying API RP 2A (2000) method by including a Reduction Factor (R) using the experimental results.
60 citations
References
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Book•
01 May 1990
TL;DR: In this paper, the authors present a consistent theoretical approach to the prediction of pile deformation and load capacity, and present parametric solutions for a wide range of cases, demonstrating how such solutions can be used for design purposes, and review the applicability of these approaches to practical problems.
Abstract: This book deals with methods of analysis that may be useful in design of pile foundations. The aims are to: 1) present a consistent theoretical approach to the prediction of pile deformation and load capacity, 2) present parametric solutions for a wide range of cases, 3) demonstrate how such solutions can be used for design purposes, and 4) review the applicability of these approaches to practical problems. (TRRL)
1,415 citations
TL;DR: In this article, a linkage type element is developed for adding rock joint stiffness to the structural stiffness matrix describing the behavior of a system of rock blocks and joints and a new classification of joints is introduced, based on the application of the joint element to finite element analysis of structures in jointed rock.
Abstract: The representation of discontinuities in analysis of blocky rock is discussed. A linkage type element is developed for addition of rock joint stiffness to the structural stiffness matrix describing the behavior of a system of rock blocks and joints. Several basic problems of jointed rock are studied. These examples demonstrate the marked influence joints may have on the stress distribution, displacements, and failure pattern of an underground opening or other structures in jointed rock. A new classification of joints is introduced, based on the application of the joint element to finite element analysis of structures in jointed rock. Normal stiffness, tangential stiffness, and shear strength are used as parameters in the classification system. The methods discussed in this paper allow a jointed rock mass to be treated as a system of blocks and links. Just as analysis of a reinforced concrete building requires detailed knowledge of the behavior of concrete alone and steel alone, the joint stiffness approach calls for and uses detailed description of the behavior of rock blocks and rock joints independently.
1,186 citations
TL;DR: In this paper, the authors presented methods for the calculation of the deflections at working loads, the ultimate lateral resistance, and moment distribution for laterally loaded single piles and pile groups.
Abstract: Methods are presented for the calculation of the deflections at working loads, the ultimate lateral resistance, and moment distribution for laterally loaded single piles and pile groups. Both unrestrained and restrained piles have been considered. The lateral deflections have been calculated using the concept of a coefficient of subgrade reaction. The ultimate lateral resistance has been evaluated. The results from the proposed methods of analysis have been compared with available test data. Satisfactory agreement was found at working loads between measured and calculated deflections and between measured and calculated maximum bending moments.
706 citations
TL;DR: In this article, a repeated application of elastic theory is used to determine the nonlinear force-deformation characteristics of soil, and soil modulus constants are adjusted for each successive trial until satisfactory compatibility is obtained in structure-pile-soil system.
Abstract: Determination of nonlinear force-deformation characteristics of soil may be done by repeated application of elastic theory; soil modulus constants are adjusted for each successive trial until satisfactory compatibility is obtained in structure-pile-soil system; equations and methods of computations are given for elastic- and rigid-pile theory; design recommendations.
450 citations
TL;DR: In this article, an approximate elastic analysis is made of the working load responses of single piles embedded in a soil of linearly increasing modulus with depth, which is of comparable generality and computational efficiency to earlier elastic solutions of the corresponding homogeneous problem.
Abstract: An approximate elastic analysis is made of the working load responses of single piles embedded in a soil of linearly increasing modulus with depth. The formulation employs, within a boundary element algorithm, the fundamental solution for point loads acting at the interface of a two-layer elastic half-space. This analysis is of comparable generality and computational efficiency to earlier elastic solutions of the corresponding homogeneous problem and has distinct advantages in practical applications over the simpler homogeneous soil model, namely, improved predictions of the response due to lateral loads and the rationalization of the selection of soil moduli. These advantages are highlighted in the comparisons made between reported observations on the behaviour of single piles from model and full scale field tests and those predicted by the theory. Comprehensive plots of the results of a parametric study are presented in non-dimensional form. Une analyse elastique approximative est faite a partir des rep...
237 citations