Ultimate pile capacity in layered soil under eccentric and inclined loads

1985 ◽  
Vol 22 (3) ◽  
pp. 399-402 ◽  
Author(s):  
G. G. Meyerhof ◽  
R. D. Purkayastha

The ultimate bearing capacity of rigid model piles and pile groups in layered soil consisting of clay overlying sand has been investigated for various combinations of eccentricity and inclination of load and with varying thicknesses of clay layer. The effect of eccentricity and inclination of the load and thickness ratios of clay layer to pile embedment in the sand on the bearing capacity can be represented by simple interaction relationships to estimate the ultimate load. The results of load tests on single model piles and freestanding pile groups are presented in the form of polar bearing capacity diagrams and are compared with the theoretical estimates. The thickness of clay layer on the sand is found to have a significant influence on the bearing capacity of single piles and pile groups. Key words: pile foundation, model test, layered soil, eccentric load, inclined load, sand, clay, analysis, bearing capacity.

1991 ◽  
Vol 28 (6) ◽  
pp. 909-917 ◽  
Author(s):  
A. S. Yalcin ◽  
G. G. Meyerhof

The bearing capacity of flexible model piles and small pile groups under axial, lateral, and various combinations of eccentric and inclined loads in layered soil consisting of clay overlying sand is investigated. Ultimate pile capacity is found to depend on the eccentricity and inclination of the load and, more significantly, on the ratio of the upper layer thickness to pile embedment. Theoretical estimates based on the concept of effective pile embedment ratio and expressed in terms of equivalent rigid piles agree reasonably well with the experimental values. The behaviour of 2 × 2 flexible model pile groups is observed to be similar to that of single piles. Key words: bearing capacity, piles, flexible pile, pile group, layered soil, sand, clay, eccentric load, inclined load, model pile test.


1989 ◽  
Vol 26 (1) ◽  
pp. 34-42 ◽  
Author(s):  
G. G. Meyerhof ◽  
D. P. Ghosh

The ultimate bearing capacity of flexible single model piles and small pile groups of timber and nylon in loose sand and soft clay has been determined under various combinations of eccentricity and inclination of the load varying in direction from vertical to horizontal. The results of the load tests are presented in the form of polar bearing capacity diagrams and they are compared with the theoretical estimates based on the concept of an effective embedment depth in terms of the behaviour of equivalent rigid piles. Reasonable agreement has been found between the observed and predicted ultimate bearing capacity of flexible piles under any combination of eccentricity and inclination of loads. Key words: flexible piles, pile groups, ultimate bearing capacity, ultimate moment, model test, eccentric load, inclined load, sand, clay.


1985 ◽  
Vol 22 (3) ◽  
pp. 267-276 ◽  
Author(s):  
G. G. Meyerhof ◽  
V. V. R. N. Sastry

The ultimate bearing capacity of instrumented vertical single rigid model piles in homogeneous loose sand and soft clay under vertical eccentric and central inclined loads has been investigated. The results of these load tests provide a more realistic lateral soil pressure distribution on the pile shaft and better theoretical estimates of pile capacity under pure moment and under horizontal load. For intermediate eccentricities and inclinations of the load, the bearing capacity can be obtained from simple interaction relationships between the axial load and moment capacities and between the axial and horizontal load capacities, respectively. The influence of lateral soil pressures due to installation of displacement piles in clay is examined in relation to the ultimate load of the pile. The analyses are compared with the results of model tests and some field case records. Key words: bearing capacity, clay, eccentric loading, horizontal load, instrumentation, model test, pile, sand.


1984 ◽  
Vol 21 (3) ◽  
pp. 389-396 ◽  
Author(s):  
G. G. Meyerhof ◽  
A.S. Yalcin

In connection with the design of offshore structures and bridge foundations, the ultimate bearing capacity of rigid piles and pile groups in clay has been determined under various combinations of eccentricity and inclination of the load varying from the vertical to horizontal directions. The results of load tests on single rigid model piles and freestanding groups are compared with theoretical estimates. The influence of eccentricity and inclination of the load on the ultimate bearing capacity can be represented by simple interaction relationships between the ultimate loads and moments and between the axial and normal components of the ultimate load. The effect of a pile cap resting on the soil in piled foundations and the influence of pile flexibility on the ultimate load are examined briefly. Key words: bearing capacity, clay, eccentric load, inclined load, pile groups, pile–soil interaction, rigid piles, ultimate load, ultimate moment.


1995 ◽  
Vol 32 (2) ◽  
pp. 204-222 ◽  
Author(s):  
G. G. Meyerhof

Previous analyses of the ultimate resistance and displacements of rigid piles under lateral loads and moments have been extended to the general case of eccentric and inclined loads on flexible piles by using the concept of effective embedment depths of equivalent rigid piles. Recent research on the behaviour of large model tests on instrumented rigid and flexible piles under eccentric and inclined loads in sand, clay, and layered soil is summarized. Reasonable agreement is found between observed and predicted behaviour. The proposed method of analysis is also supported by comparison with the results of many field case records of single piles and large pile groups under lateral loads indifferent types of soils. Key words : bearing capacity, displacement, eccentric loads, inclined loads, layered soil, pile.


2021 ◽  
Vol 7 (4) ◽  
pp. 730-746
Author(s):  
Amanpreet Kaur ◽  
Harvinder Singh ◽  
J. N. Jha

This paper presents the results of three dimensional finite element analysis of laterally loaded pile groups of configuration 1×1, 2×1 and 3×1, embedded in two-layered soil consisting of soft clay at liquid limit overlying dense sand using Plaxis 3D. Effects of variation in pile length (L) and clay layer thickness (h) on lateral capacity and bending moment profile of pile foundations were evaluated by employing different values of pile length to diameter ratio (L/D) and ratio of clay layer thickness to pile length (h/L) in the analysis. Obtained results indicated that the lateral capacity reduces non-linearly with increase in clay layer thickness. Larger decrease was observed in group piles. A non-dimensional parameter Fx ratio was defined to compare lateral capacity in layered soil to that in dense sand, for which a generalized expression was derived in terms of h/L ratio and number of piles in a group. Group effect on lateral resistance and maximum bending moment was observed to become insignificant for clay layer thickness exceeding 40% of pile length. For a fixed value of clay layer thickness, lateral capacity and bending moment in a single pile increased significantly with increase in pile length only up to an optimum embedment depth in sand layer which was found to be equal to three times pile diameter and 0.21 times pile length for pile with L/D 15. Scale effect on lateral capacity has also been studied and discussed. Doi: 10.28991/cej-2021-03091686 Full Text: PDF


2011 ◽  
Vol 243-249 ◽  
pp. 4402-4407
Author(s):  
Yong Hong Miao ◽  
Guo Jun Cai ◽  
Song Yu Liu

Six methods to determine axial pile capacity directly based on piezocone penetration test (CPTU) data are presented and evaluated. Analyses and evaluation were conducted on three types piles that were failed during pile load testing. The CPT methods, as well as the CPTU methods, were used to estimate the load carrying capacities of the investigated piles (Qp ). Pile load test were used to determine the measured load carrying capacities (Qm). The pile capacities determined using the different methods were compared with the measured pile capacities obtained from the pile load tests. Two criteria were selected as bases of evaluation: the best fit line for Qp versus Qm and the arithmetic mean and standard deviation for the ratio Qp /Qm. Results of the analyses showed that the best methods for determining pile capacity are the CPTU methods.


2020 ◽  
Vol 10 (16) ◽  
pp. 5492
Author(s):  
Michał Baca ◽  
Włodzimierz Brząkała ◽  
Jarosław Rybak

This work examined a new method of bi-directional static load testing for piles, referencing the Osterberg test. Measurements were taken, on a laboratory scale, using six models of piles driven into a box filled with sand. This method allowed for separate measurements of pile base and pile shaft bearing capacities. Based on the results, the total pile bearing capacity and equivalent Q–s diagrams were estimated. The results obtained show that the structure of the equivalent curve according to Osterberg is a good approximation of the standard Q–s curve obtained from load tests, except for loads close to the limit of bearing capacity (those estimates are also complicated by the inapplicability and ambiguity of a definition of the notion of limit bearing capacity); the equivalent pile capacity in the Osterberg method represents, on average, about 80% of the capacity from standard tests.


1981 ◽  
Vol 18 (2) ◽  
pp. 297-300 ◽  
Author(s):  
G. G. Meyerhof

The ultimate bearing capacity of rigid vertical and batter piles and pile groups in clay has been determined under various inclinations of the load, varying from the vertical to horizontal directions. The results of load tests on single model piles of different lengths and inclinations and on free-standing groups and piled foundations are compared with theoretical estimates. The influence of load inclination on the bearing capacity can be represented by simple interaction relationships between the axial and normal components of the ultimate load. The effect of eccentricity of the load on the ultimate bearing capacity of pile groups is discussed on the basis of previous theory and model test results.


1963 ◽  
Vol 1 (1) ◽  
pp. 16-26 ◽  
Author(s):  
George Geoffrey Meyerhof

The first part of the paper summarizes the results of recent research on the bearing capacity of spread foundations of various shapes under a central vertical load and outlines the effects of foundation depth, eccentricity and inclination of the load. Simple formulae have been derived for use in practice and their application to the design of rigid and flexible foundations is briefly indicated.The second part of the paper discusses the bearing capacity of single piles under vertical and inclined loads. The bearing capacity of piled foundations and free-standing pile groups is outlined, and the results of model tests on pile groups under central and eccentric loads are briefly analysed in relation to some problems in practice.


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