Redundancy analysis - Computational Analysis and Design of Bridge Structures - page 471

Table 15.5 Load factors in relation to load combinations and load cases
Load combination
with element-cut
status

Load factors

Load
cases

γ DC γ DW γ LL truck γ LL lane γ PL

Extreme event III
(no cut)

1 1.25 1.5 1.3 × 1.33 1.3 -

2 1.25 1.5 1.1 × 1.33 - -

3 1.25 1.5 1.3

1.3 × 1.33

-

4 1.25 1.5 1.1 × 1.33 - -

Extreme event IV
(cut element)

1 1.05 1.05 1.15 × 1.33 1.15

-

2 1.05 1.05 1.05 × 1.33

- -

3 1.05 1.05 1.15 × 1.33 1.15

-

4 1.05 1.05 1.05 × 1.33

- -

Table 15.6 Computer-run cases in relation to element-cut and load cases (one lane case)
Cases of element cut Load cases Computer-run cases

No cut Each with load cases P82CLnocut, P82L3nocut,

PHL93CLnocut,
PHL93L3nocut

Cut 1
(first bottom chord)

1. PHL-93 truck at midspan
and PHL-93 lane all over

P82CLcut1, P82L3cut1,
PHL93CLcut1,
PHL93L3cut1

Cut 3
(third bottom chord)

2. P-82 truck at midspan P82CLcut3, P82L3cut3,

PHL93CLcut3,
PHL93L3cut3

Cut 5
(fifth bottom chord)

3. PHL-93 truck at 1/3 L P82CLcut5, P82L3cut5,

PHL93CLcut5,
PHL93L3cut5

and PHL-93 lane all over

Cut 28
(first diagonal chord)

4. P-82 truck at 1/3 L P82CLcut28, P82L3cut28,

PHL93CLcut28,
PHL93L3cut28

Cut 31
(second diagonal chord)

P82CLcut31, P82L3cut31,
PHL93CLcut31,
PHL93L3cut31

3. No member exhibits a combined (axial and bending) stress that
exceeds the allowable given in AASHTO specifications or Penn DOT
Design Manual.

4. Noncomposite action is conservatively considered for the deck sys-
tem. For 3D analysis, floor beams are considered as part of the frame
action. The model showed that the stresses of floor beams (elements
103-152) are under the allowables and they are not the governing
cases compared to the truss members.

5. No yielding is found in any element of these four load cases.