Large numbers of 1950's vintage conventionally reinforced concrete (CRC)
bridges remain in-service in the national bridge inventory. Many of these bridges are
lightly reinforced for shear. Evaluation of these bridges to prevent unnecessary and
costly repairs requires refined analytical techniques. This dissertation presents finite
element (FE) modeling and comparisons of various analytical methods for predicting
capacity of CRC girders typical of reinforced concrete deck girder (RCDG) bridges.
Analyses included bridge-system load distribution, member capacity prediction, and
consideration of corrosion damage for strength deterioration.
Two in-service RCDG bridges were inspected and instrumented to measure
response under known load configurations. Load distribution was developed for the
bridges based on the field data. Comparisons with AASHTO factors indicated the
design factors for load distribution are conservative. Load distribution of the tested
bridges was numerically obtained using FE analysis. The comparisons between
predicted results and field-test data indicated the elastic FE analysis can be used for
modeling of cracked RCDG bridges to predict load distribution factors for more
accurate bridge evaluation.
Analyses were performed for a large set of full-size RCDG, designed to
reflect 1950's vintage details, and tested using various loading configurations. Four
different analysis methods were used to predict the capacity of the specimens
considering details of various stirrup spacing, debonded stirrups, flexural-bar cutoff,
anchorage of flexural reinforcing, and moving supports.
Nonlinear FE analyses were performed to predict behavior of two groups of
experimental reinforced concrete (RC) specimens. Two different span-to-depth
ratios were included: 2.0 and approximately 3.0. Concrete confinement effects were
included in the material modeling. A quasi-displacement control technique was
developed to reduce solution times. The FE predicted results correlated well with
the experimental data.
FE modeling techniques were developed to isolate different contributions of
corrosion damage to structural response of experimental RC beams designed to
produce diagonal-tension failures. Corrosion-damage parameters included concrete
cover spalling; uniform stirrup cross-sectional loss; local stirrup cross-sectional loss
due to pitting; and debonding of corrosion-damaged stirrups from the concrete. FE
analyses were performed including both individual and combined damages. The FE
results matched experimental results well and quantitatively estimated capacity
reduction of the experimental specimens. / Graduation date: 2005 / Best scan available.
| Identifer | oai:union.ndltd.org:ORGSU/oai:ir.library.oregonstate.edu:1957/29598 |
| Date | 25 August 2004 |
| Creators | Potisuk, Tanarat |
| Contributors | Higgins, Christopher C. |
| Source Sets | Oregon State University |
| Language | en_US |
| Detected Language | English |
| Type | Thesis/Dissertation |
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