Reinforced concrete bridges - Computational Analysis and Design of Bridge Structures - page 120

simulated line beam model gives more conservative results for most of the
locations.

4.6 2d and 3d IlluStRated exampleS:
Rc t-Beam BRIdge

This example of a single-span RC T-beam bridge was adopted from AASHTO
LRFD manual (2013b). Cross-sectional view of the bridge is shown in
Figure 4.14. The simple span concrete T-beam bridge consists of 6″ thick
concrete deck and four monolithically casted concrete beams. This is a non-
skewed bridge and ideal for line girder modeling. The beams are supported
at the ends by the abutments connected at the bottom, and its computer ren-
dering by Merlin-DASH (Fu 2012) is shown in Figure 4.15. For production
modeling of load-rating purpose, conventional elastic sectional modeling
technique, instead of nonlinear modeling as described in Section 4.3.2, is used.
Two different linear elastic models were built for comparison. First-line
girder model was built by Merlin-DASH. For the T-beam bridge example,
a T-beam with flange width of 6′-6 1/4″ (2.0 m), shown as a straight beam
line (Figure 4.15), is considered for modeling and analysis purpose.
Based on AASHTO LRFD specifications (2013a), the distribution of live
loads for moment in interior beams with more than one lane loaded, which
is the case here for comparison, is

22′-0′′

Roadway
C.L. Symmetry

Detail “A”

3′-0′′ 6′-6 1/4′′ 6′-6 1/4′′ 6′-6 1/4′′ 3′-0′′

(a)

A.C. Overlay
(Measured in field)

#5 @ 9′′

All bars
7/8′′ square

1′-3′′

Detail “A”

(b)

Figure 4.14 (a, b) Cross-sectional views of the T-beam bridge.