Location

Arlington, Virginia

Session Start Date

8-11-2008

Session End Date

8-16-2008

Abstract

Micropiles were selected for several upgrades to a paper machine at the Nippon Paper Industries USA Company in Port Angeles, Washington. This paper presents several aspects of the micropile design and subsequent load test performance for two separate upgrades at the paper mill. The micropile load tests, performed in tension and compression, provide a reference for micropile performance in medium dense to dense, gravelly sand. Comparison of the load test performance suggests that the common assumption of neglecting the contribution of end-bearing resistance does not adequately model micropile behavior. Additionally, evidence is presented for load transfer through the micropile casing. The load test performance is interpreted in the framework of a simple, global stiffness degradation technique, which provides an estimate of bond stresses. The analyses suggest that the mode of loading (e.g., tension or compression) influences the load transfer properties for the small diameter micropiles.

Department(s)

Civil, Architectural and Environmental Engineering

Appears In

International Conference on Case Histories in Geotechnical Engineering

Meeting Name

Sixth Conference

Publisher

Missouri University of Science and Technology

Publication Date

8-11-2008

Document Version

Final Version

Rights

© 2008 Missouri University of Science and Technology, All rights reserved.

Document Type

Article - Conference proceedings

File Type

text

Language

English

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Aug 11th, 12:00 AM Aug 16th, 12:00 AM

Tension and Compression Micropile Load Tests in Gravelly Sand

Arlington, Virginia

Micropiles were selected for several upgrades to a paper machine at the Nippon Paper Industries USA Company in Port Angeles, Washington. This paper presents several aspects of the micropile design and subsequent load test performance for two separate upgrades at the paper mill. The micropile load tests, performed in tension and compression, provide a reference for micropile performance in medium dense to dense, gravelly sand. Comparison of the load test performance suggests that the common assumption of neglecting the contribution of end-bearing resistance does not adequately model micropile behavior. Additionally, evidence is presented for load transfer through the micropile casing. The load test performance is interpreted in the framework of a simple, global stiffness degradation technique, which provides an estimate of bond stresses. The analyses suggest that the mode of loading (e.g., tension or compression) influences the load transfer properties for the small diameter micropiles.