Session Start Date

5-6-1984

Abstract

The paper reports result of a comprehensive full scale field study expressly undertaken to monitor negative drag on a large diameter, bored cast-in-place reinforced concrete pile installed to rock in a deep deposit of soft marine clay of pleistaceae to recent origin. The pile was instrumented with load cells and the ground around the pile with piezometers and settlement gauges. The negative drag was generated by loading the ground around the pile in stages. The ground settlements were accelerated by providing vertical sand drains. The observational data were utilized in figuring out the influence of surcharge on the depth of clay responsible for generating the negative drag. The study has provided computational methodology for estimation of negative drag in terms of total and effective stresses. The inevitability of large ground settlement with respect to the pile brought out the non-importance of precisely ascertaining the magnitude of relative displacement necessary for mobilization of negative drag.

Department(s)

Civil, Architectural and Environmental Engineering

Appears In

International Conference on Case Histories in Geotechnical Engineering

Meeting Name

First Conference

Publisher

University of Missouri--Rolla

Publication Date

5-6-1984

Document Version

Final Version

Rights

© 1984 University of Missouri--Rolla, All rights reserved.

Document Type

Article - Conference proceedings

File Type

text

Language

English

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May 6th, 12:00 AM

Down Drag on an Instrumental Bored Pile in Soft Clay

The paper reports result of a comprehensive full scale field study expressly undertaken to monitor negative drag on a large diameter, bored cast-in-place reinforced concrete pile installed to rock in a deep deposit of soft marine clay of pleistaceae to recent origin. The pile was instrumented with load cells and the ground around the pile with piezometers and settlement gauges. The negative drag was generated by loading the ground around the pile in stages. The ground settlements were accelerated by providing vertical sand drains. The observational data were utilized in figuring out the influence of surcharge on the depth of clay responsible for generating the negative drag. The study has provided computational methodology for estimation of negative drag in terms of total and effective stresses. The inevitability of large ground settlement with respect to the pile brought out the non-importance of precisely ascertaining the magnitude of relative displacement necessary for mobilization of negative drag.