Pile

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)

Abstract: An approximate closed-form solution has been obtained to the problem of a vertically loaded pile in a linear elastic soil. This solution has been derived by uncoupling the load-transfer for the pile into separate shaft and base components. Throughout the development of the analysis, well-proven numerical techniques have been used to verify that the assumptions made are reasonable. The final form of the solution gives the load-settlement ratio of the pile in terms of the pile geometry and stiffness and soil stiffness. The analysis has been used to back-analyze pile tests, enabling immediate estimates of the soil stiffness profile to be made from the measured load-settlement curve of the pile. The application of the method to pile design is demonstrated—design curves being sketched for piles of different geometries in two typical soft clay deposits.

Abstract: Conventional bearing capacity of driven and bored piles in sand and nonplastic silt is limited to short piles above the critical depth of penetration. The bearing capacity of longer piles can be estimated from the limiting values of the point resistance and skin friction using either the friction angle of the soil or preferably the results of static and standard penetration tests directly. For driven and bored piles in clay and plastic silt, conventional bearing capacity theory using the undrained shear strength of the soil represents mainly the failure condition at the pile points. The positive and negative shaft resistance some months after pile installation is governed by the drained shear strength of remolded soil and can be estimated from skin friction factors, provided the earth pressure coefficient at rest of the deposit is known. The ultimate load of pile groups and the settlement of pile foundations are examined.

Abstract: The majority of piles encountered in practice may be regarded as ‘flexible’ under lateral loading. That is, the induced deformations and bending moments are confined to the upper part of the pile and the overall length of the pile does not significantly affect the response of the pile. The results of a parametric study, conducted using the finite element method and treating the soil as an elastic continuum with a linearly varying soil modulus, are presented as simple algebraic expressions. These expressions are similar in form to those which arise from a Winkler idealization of the soil, enabling immediate estimates to be made of: the active length of the pile; the ground level deformations; and the maximum bending moment down the pile. In addition, expressions are presented quantifying the effect of interaction between neighbouring piles. from which the behaviour of groups of piles subjected to lateral loading may be deduced. Application of the solutions is demonstrated by the analysis of lateral loading...

Abstract: In this chapter a numerical method for the solution of the problem of a beam on an elastic foundation is presented. Special care will be taken that the program can be used for beams consisting of sections of unequal length, as the program is to be used as a basis for a sheet pile wall program, and for a program for a laterally loaded pile in a layered soil.