Traditionally, analyses developed for circular piles have also been used for rectangular piles by replacing in calculations the rectangular pile with a circular pile of equivalent area. In this paper, we present a settlement analysis that applies to piles with either rectangular or circular cross sections installed in multilayered soil deposits. The analysis follows from the solution of the differential equations governing the displacements of the pile-soil system obtained using variational principles. The input parameters needed for the analysis are the pile geometry and the elastic constants of the soil and pile. Pile displacements and vertical soil displacements calculated using this analysis match well those from finite-element analysis. A parametric study highlights some important insights for rectangular and circular piles in multilayered soil. A user-friendly spreadsheet program (ALPAXL) was developed to facilitate the use of the analysis. Examples illustrate the use of the analysis in design.
1 December 2009 in Journal of Geotechnical and Geoenvironmental Engineering
Most of the current design methods for driven piles were developed for closed-ended pipe piles driven in either pure clay or clean sand. These methods are sometimes used for H piles as well, even though the axial load response of H piles is different from that of pipe piles. Furthermore, in reality, soil profiles often consist of multiple layers of soils that may contain sand, clay, silt or a mixture of these three particle sizes. Therefore, accurate prediction of the ultimate bearing capacity of H piles driven in a mixed soil is very challenging. In addition, although results of well documented load tests on pipe piles are available, the literature contains limited information on the design of H piles. Most of the current design methods for driven piles do not provide specific recommendations for H piles. In order to evaluate the static load response of an H pile, fully instrumented axial load tests were performed on an H pile ( HP 310×110 ) driven into a multilayered soil profile consisting of soils com...
Explicit elastic solutions for a vertically loaded single pile embedded in multilayered soil are presented. Solutions are also provided for the case in which the pile base rests on a rigid material. Energy principles are used in the derivation of the governing differential equations. The solutions, which satisfy compatibility of displacement in the vertical and radial directions, were obtained by determining the unknown integration constants using the boundary conditions, Cramer's rule, and a recurrence formula. The solutions provide the pile vertical displacement as a function of depth, the load-transfer curves, and the vertical soil displacement as a function of the radial distance from the pile axis at any depth. The use of the analysis is illustrated for a pile that was load-tested under well-documented conditions by obtaining load–transfer and load–settlement curves that are then compared with those obtained from the load test.
25 November 2011 in International Journal for Numerical and Analytical Methods in Geomechanics
Despite the fact that results of many instrumented pile load tests have been reported in the literature, it is difficult to find well-documented instrumentation procedures that can be used when planning a load testing programme. A load test programme designed to investigate various aspects of the design and behaviour of driven steel piles is discussed in the present paper. Although the literature contains information on load testing of instrumented piles driven in either sand or clay, limited information is available regarding their axial load response in transitional soils (soils composed of various amounts of clay, silt and sand). Results are presented for fully instrumented axial load tests performed on an H pile and a closed-ended pipe pile driven into a multilayered soil profile consisting of transitional soils. In addition, the load testing planning, the instrumentation of the piles, the testing methods and the interpretation of the pile testing data are discussed in detail in the context of this and other load testing programmes described in the literature, in order to illustrate the various steps.