Identifier

etd-07102008-112235

Degree

Master of Science in Civil Engineering (MSCE)

Department

Civil and Environmental Engineering

Document Type

Thesis

Abstract

Construction projects in coastal Louisiana often require pile foundations as a result of the soft soils present, which complicate cast‐in‐place foundation construction and provide minimal support to shallow foundations. During a driven pile project, the engineering phase will require soil characterization and pile capacity determination, while construction will require quality assurance. These three elements, soil characterization, capacity determination, and quality assurance, are commonly accomplished using in‐situ and nondestructive testing. In this thesis, the application of some of these in‐situ and nondestructive methodologies to a project in Coastal Louisiana are examined. The Louisiana Transportation Research Center (LTRC) has released computer software that aids in soil characterization and pile capacity determination using cone penetration testing. This software utilizes a probabilistic approach to soil classification, which calculates the probabilities of the tested soil being clay, silt, or sand. The software also provides pile capacity computations. However, the software does not employ a method that considers the pore water pressure measurements obtained by the piezocone. This research examines the Statistical to Fuzzy Approach Toward CPT Classification (Zhang, et al., 1999) and evaluates whether the soil type probabilities calculated by the method correlate to soil grain size distribution. This was accomplished by comparing laboratory grain size tests on soil samples with the processed data from nearby cone penetrometer soundings. Furthermore, the pile capacity methods utilized in the LTRC software are compared to pile load tests alongside a capacity prediction method that uses pore water pressure measurements. The intent is to determine whether this CPTu method (Fellenius, et al., 1997), yields more accurate results than those methods already included in the software. Finally, the Case damping constants used in high‐strain dynamic testing are evaluated against published recommended values. Although this damping constant is not a measurable soil parameter, it is related to grain size. Therefore, it should be possible to calibrate the high‐strain dynamic test for a range of acceptable damping values at a given site, provided the soil conditions do not vary significantly. This evaluation is accomplished by calibrating high‐strain dynamic test data to several full‐scale static load tests.

Date

2008

Document Availability at the Time of Submission

Release the entire work immediately for access worldwide.

Committee Chair

Radhey Sharma

DOI

10.31390/gradschool_theses.2408

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