Bearing capacity of rigid piles under eccentric and inclined loads

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.

1986 ◽  
Vol 23 (3) ◽  
pp. 281-286 ◽  
Author(s):  
V. V. R. N. Sastry ◽  
G. G. Meyerhof

The lateral soil pressures, tip load, and displacements of instrumented single rigid model piles in homogeneous loose sand and soft clay under vertical eccentric and central inclined loads have been investigated. A comparison of the test results with theoretical pressure distributions and displacements of the pile for the working load range has been made. Reasonable agreement has been found between the observed and predicted displacements and suggested nondimensional p–y curves. The analyses are also compared with the results of some field case records. Key words: displacements, clay, eccentric load, horizontal load, lateral soil pressure, instrumentation, model test, pile, sand.


1986 ◽  
Vol 23 (4) ◽  
pp. 451-457 ◽  
Author(s):  
V. V. R. N. Sastry ◽  
G. G. Meyerhof ◽  
T. Koumoto

The lateral soil pressures, ultimate bearing capacity, and displacements of instrumented vertical single rigid model piles in a layered system consisting of soft clay overlying loose sand and subjected to vertical eccentric and central inclined loads have been investigated. The variation of lateral soil pressures and the tip resistance of the pile are analysed with respect to the total load or moment on the pile. Theoretical estimates of pile capacity in homogeneous soils under pure moment and under horizontal load have been extended to piles in a layered system. For intermediate eccentricities and inclinations of the load, the pile capacity can be estimated from simple interaction relations or semiempirical eccentricity and inclination factors. The pile displacements are analysed in the light of linear elastic theory and nondimensional p − y curves. Reasonable agreement has been found between the measured and predicted values. Key words: bearing capacity, clay, displacements, eccentric load, horizontal load, lateral pressure, layered system, model test, pile, sand.


1995 ◽  
Vol 32 (3) ◽  
pp. 387-396 ◽  
Author(s):  
V.V.R.N. Sastry ◽  
G.G. Meyerhof

The lateral soil pressures, bending moments, pile displacements at the ground surface, and the bearing capacity of instrumented vertical single flexible model piles in a layered clay system consisting of medium clay overlying soft clay under vertical eccentric and central inclined loads have been investigated. The results of these load tests are compared with theoretical estimates based on the concept of the effective embedment depth of equivalent rigid piles for ultimate and elastic cases. Reasonable agreement has been found between the observed and predicted behaviour of flexible piles. The analyses are also compared with the results of some field case records. Key words : bearing capacity, clay, instrumentation, model test, pile.


1990 ◽  
Vol 27 (1) ◽  
pp. 19-28 ◽  
Author(s):  
V. V. R. N. Sastry ◽  
G. G. Meyerhof

The lateral soil pressures, bending moments, pile displacements at ground surface, and bearing capacity of instrumented vertical single flexible model piles in homogeneous loose sand and soft clay under central inclined loads have been investigated. The results of these load tests are compared with theoretical estimates based on the concept of an effective embedment depth of equivalent rigid piles. Reasonable agreement has been found between the observed and predicted behaviour of flexible piles. The analyses are also compared with the results of some field case records. Key words: bending moments, clay, displacements, inclined loads, instrumentation, lateral soil pressure, model test, pile, sand.


1987 ◽  
Vol 24 (4) ◽  
pp. 471-478 ◽  
Author(s):  
G. G. Meyerhof ◽  
V. V. R. N. Sastry

The results of full-displacement pressuremeter tests in beds of sand, clay, and layered soil have been used to estimate the lateral soil pressures, ultimate capacity, and displacements of instrumented rigid model piles under eccentric and inclined loads. Comparisons of these estimates with observations on the piles under horizontal load and pure moment have been made and reasonable agreement is found. The analyses are also compared with some field case records. Key words: bearing capacity, clay, displacements, horizontal load, lateral pressure, layered soil, model test, moment, pile, pressuremeter, sand.


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.


1987 ◽  
Vol 24 (1) ◽  
pp. 145-149 ◽  
Author(s):  
V. V. R. N. Sastry ◽  
G. G. Meyerhof

The lateral soil pressure distribution, pile capacity, and displacements of instrumented single rigid bored piles subjected to pure moment and horizontal load have been investigated. The influence of method of pile installation on the above parameters is studied by comparing the behaviour of bored piles with that of jacked piles. It was concluded that the method of installation has practically no effect so far as the net lateral soil pressures and pile capacity are concerned, but the displacements may be up to three times larger for a bored pile than for a jacked pile under working loads. Key words: clay, horizontal load, installation, model test, moment, pile.


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.


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.


Author(s):  
Qilin Yin ◽  
Jinjin Zhai ◽  
Sheng Dong

The overall bearing capacity of a jack-up rig under horizontal load is conducted using finite element models that consider the deck–foundation–soil interaction. In these models, the simplified horizontal load acts on the deck and increases until the platform loses its stability. The effects of the self-weight of the platform W and load direction α on the ultimate horizontal bearing capacity Hult are investigated, and W- Hult failure envelopes under different α conditions are obtained. Two typical seabed types, including the double-layer seabed of sand overlying soft clay and the single-layer seabed of sand, are considered. The results show that a critical self-weight Wcritical exists in the double-layer seabed. Based on Wcritical, the failure of the platform presents two different modes. When W <  Wcritical, the windward leg is pulled up, and Hult increases with the increase in W. When W >  Wcritical, the failure mode is the leeward leg or legs puncturing the bearing sand layer, and Hult decreases with the increase in W. In the single-layer seabed, the failure mode is the windward leg being pulled up, and Hult increases with the increase in W throughout the whole range. The W- Hult envelopes in these two types of seabeds are basically the same when W <  Wcritical.


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