Redundancy analysis - Computational Analysis and Design of Bridge Structures - page 469

16.65 m (55′)

3.35 m 1.2 m 1.2 m 7.3 m (24′) 1.2 m

(4′)

1.2 m 1.2 m

(11′) (4′) (4′) (4′) (4′)

8.0 kip 32.0 kip 32.0 kip

70 kN
(15 kip)

120 kN
(27 kip)

120 kN
(27 kip)

120 kN
(27 kip)

120 kN
(27 kip)

120 kN
(27 kip)

120 kN
(27 kip)

120 kN
(27 kip)

14′ 0″ 14′ 0″ to 30′ 0″

6′ 0″

(b)
Figure 15.6 Penn DOT (a) PHL-93 and (b) P-82 permit truck configuration.

(a) PHL-93 truck P-82 permit truck

15.3.2 Results
A series of analysis cases, which are defined in Table 15.4, were developed
to assess the appropriate AASHTO code requirement (AASHTO 2012,
2013) as applied to each member bridge configuration and failure mode.
Analysis case 1 can be obtained by either TRAP (BEST Center 2006) or
ANSYS program. The results of this analysis case are not covered in this
topic. Analysis cases 2 and 3, which are in the scope of the redundancy
analysis, have to be obtained by 3D analysis, and the ANSYS program is
used. Specifically, a total of 24 ANSYS runs with 24 analysis cases were
investigated for the redundancy analysis (Table 15.6), each case requiring
the application of multiple loadings for the 188 finite elements, which com-
pose each bridge configuration.
Contained within this section is a summary of results of the ANSYS
analysis of the Foxstop Road Bridge.

15.3.2.1 Extreme event III
The 3D frame analysis uses the entire truss-deck system assemblage in
determining the stress in two plane trusses and floor beams. A review of
four load cases with no element cut reveals the following:

1. The maximum and average stresses due to bending for all dead and
maximum live load combinations are investigated as specified by
AASHTO LRFD specifications (AASHTO 2013) and Penn DOT
Design Manual Part IV (Penn DOT 2000).

2. The level of secondary stresses is generally low, and predominant
stresses are axial stresses on the truss panels.