Alternative Title

Paper No. 1.50

Location

St. Louis, Missouri

Session Start Date

3-8-1998

Session End Date

3-15-1998

Abstract

In this study, variation with load was analyzed in terms of the settlement/diameter ratio, of deformation modulus Kp of soil at the tip of a precased concrete pile as bored, defined as the slope of a straight line extending from the point of origin of its stress-settlement curve at its tip as determined through a vertical loading test and intersecting with such curve at the point corresponding to the settlement at each load level as applied during such loading test. Data were taken from a series of vertical loading tests conducted on 18 piles. From the study, the deformation modulus Kp was found:

(1) to decrease exponentially with an increase in settlement/diameter ratio Sp/Op,

(2) to range from 200 to 300 kN/m3, when ultimate load was taken for the one at which a given pile settled by 10% of its tip diameter at its tip, independent on its diameter, length, and the type of soil at its tip,

(3) to be from 600 to 2,000 kN/m3 and 300 to 600 kN/m3 at settlement/diameter ratios of 2% and 4% at pile tip respectively, these settlements being deemed as reasonable criteria to determine the ultimate bearing load of a pile by means of a conventional loading test, and

(4) to converge to a certain value with an increase in settlement/diameter ratio Sp/Dp, regardless of the diameter of the pile, and therefore such modulus can be identified through a loading test on a small diameter pile rather than a large diameter pile, resulting in an economy.

Department(s)

Civil, Architectural and Environmental Engineering

Appears In

International Conference on Case Histories in Geotechnical Engineering

Meeting Name

Fourth Conference

Publisher

University of Missouri--Rolla

Publication Date

3-8-1998

Document Version

Final Version

Rights

© 1998 University of Missouri--Rolla, All rights reserved.

Document Type

Article - Conference proceedings

File Type

text

Language

English

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Mar 8th, 12:00 AM Mar 15th, 12:00 AM

Deformation Modulus of Soil at the Tip of a Bored Pile

St. Louis, Missouri

In this study, variation with load was analyzed in terms of the settlement/diameter ratio, of deformation modulus Kp of soil at the tip of a precased concrete pile as bored, defined as the slope of a straight line extending from the point of origin of its stress-settlement curve at its tip as determined through a vertical loading test and intersecting with such curve at the point corresponding to the settlement at each load level as applied during such loading test. Data were taken from a series of vertical loading tests conducted on 18 piles. From the study, the deformation modulus Kp was found:

(1) to decrease exponentially with an increase in settlement/diameter ratio Sp/Op,

(2) to range from 200 to 300 kN/m3, when ultimate load was taken for the one at which a given pile settled by 10% of its tip diameter at its tip, independent on its diameter, length, and the type of soil at its tip,

(3) to be from 600 to 2,000 kN/m3 and 300 to 600 kN/m3 at settlement/diameter ratios of 2% and 4% at pile tip respectively, these settlements being deemed as reasonable criteria to determine the ultimate bearing load of a pile by means of a conventional loading test, and

(4) to converge to a certain value with an increase in settlement/diameter ratio Sp/Dp, regardless of the diameter of the pile, and therefore such modulus can be identified through a loading test on a small diameter pile rather than a large diameter pile, resulting in an economy.