2 International Conference on Timber Bridges · 3/10/2019 · Las Vegas, 2013 . TWO BRIDGES BUILT...
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Two Bridges Built Using Black Locust Wood 2 nd International Conference on Timber Bridges Ryan Woodward Ted Zoli Las Vegas, 2013
Transcript of 2 International Conference on Timber Bridges · 3/10/2019 · Las Vegas, 2013 . TWO BRIDGES BUILT...
Two Bridges Built Using Black Locust Wood
2nd International Conference on Timber Bridges
Ryan Woodward
Ted Zoli
Las Vegas, 2013
TWO BRIDGES BUILT USING BLACK LOCUST WOOD 2
Squibb Bridge
Brooklyn, NY
TWO BRIDGES BUILT USING BLACK LOCUST WOOD 3
FURMAN STREET
121’-0”
SQUIBB PARK
(BEYOND)
17’-0”
CL
.
5%
121’-0”
HOTEL/RESIDENTIAL
(BEYOND)
DRIVEWAY 12’-6”
CL
.
Underslung Suspension Bridge: • Highly efficient form
• Material palette from BBP
• Small dia. Black Locust
• Steel cables & connections
VIEW A-A
PLAN
TWO BRIDGES BUILT USING BLACK LOCUST WOOD 4
TWO BRIDGES BUILT USING BLACK LOCUST WOOD 5
Black Locust Timber:
• Sustainable • Small diameters – harvested young • Fast growth • Locally sourced • Rot resistant – no coating required
• Strong • Low shrinkage
(11.4% vol.)
Galvanized steel cables & hardware
TWO BRIDGES BUILT USING BLACK LOCUST WOOD 7
TWO BRIDGES BUILT USING BLACK LOCUST WOOD 8
Ratios of dry to green clear wood properties
Modulus of Rupture Modulus of Elasticity Compression Parallel to Grain
1.40 1.11 1.50
(ASTM D2555)
TWO BRIDGES BUILT USING BLACK LOCUST WOOD 9
Locust Borer
(Megacyllene robiniae)
Lunch
TWO BRIDGES BUILT USING BLACK LOCUST WOOD 10 Timber Piles – standard and proprietary connections
TWO BRIDGES BUILT USING BLACK LOCUST WOOD 11
TWO BRIDGES BUILT USING BLACK LOCUST WOOD 12
Structural Systems - Triakonta:
TWO BRIDGES BUILT USING BLACK LOCUST WOOD 13
Turning a Black Locust Log, Cornell University, 2010
TWO BRIDGES BUILT USING BLACK LOCUST WOOD 14
Structural Systems – Prestressed Segmented Arch:
TWO BRIDGES BUILT USING BLACK LOCUST WOOD 15
Annular band connections on communication towers up to 40 m tall.
TWO BRIDGES BUILT USING BLACK LOCUST WOOD 16
• Capped end connections
• Modular kit-of-parts
• Simple fabrication & erection
TWO BRIDGES BUILT USING BLACK LOCUST WOOD 17 Four Bar Linkage
TWO BRIDGES BUILT USING BLACK LOCUST WOOD 18
TWO BRIDGES BUILT USING BLACK LOCUST WOOD 19
TWO BRIDGES BUILT USING BLACK LOCUST WOOD 20
Squibb Bridge
Brooklyn, NY
TWO BRIDGES BUILT USING BLACK LOCUST WOOD 21
TA Footbridge
Vassar College, Poughkeepsie, NY
TWO BRIDGES BUILT USING BLACK LOCUST WOOD 22
Pressure treated wood deck, on unpainted steel beams
Advanced corrosion, significant section loss
TWO BRIDGES BUILT USING BLACK LOCUST WOOD 23
Elevation
Axial force in lattice members (kips)
AASHTO STR-I combo
Axial force in chords & arch rib (kips)
X
Y
Z
-1.0
-1.3
-2.0
-2.5
-3.2
-5.6
X
Y
Z
60.0
-47.9
Elevation
Axial force in lattice members (kips)
AASHTO STR-I combo
Axial force in chords & arch rib (kips)
X
Y
Z
-1.0
-1.3
-2.0
-2.5
-3.2
-5.6
X
Y
Z
60.0
-47.9
Axial force in chords & arch rib (kips) Axial force in lattice members (kips)
AASHTO Strength-I Combination
Elevation
TWO BRIDGES BUILT USING BLACK LOCUST WOOD 24
-4-2024
V0 VAB VBC VCD VD
Shea
r (k
ips)
Peg Shear Diagrams Top Chord
Section - Top Chord
0
1
2
3
4
0.00.51.01.52.02.53.03.54.0
B1
B3
B5
B7
B9
B1
1B
13
B1
5B
17
B1
9B
21
B2
3B
25
B2
7
No
. of P
egs
Bo
tto
m C
ho
rdM
ax. S
hea
r (k
ips)
0
1
2
3
4
0.00.51.01.52.02.53.03.54.0
T1 T4 T7 T10
T13
T16
T19
T22
T25
T28
No
. of P
egs
Top
Ch
ord
Max
. Sh
ear
(kip
s)
L BRIDGE (SYMM.)
C
0
1
2
3
4
0.00.51.01.52.02.53.03.54.0
A1
A3
A5
A7
A9
A1
1A
13
A1
5A
17
A1
9A
21
A2
3A
25
A2
7
No
. of P
egs
Arc
h R
ibM
ax. S
hea
r (k
ips)
Panel Point
Max Shear Force per shear plane (kips) No. of Pegs Figure 6 TA Bridge: maximum shear force per peg
shear plane and no. of pegs at each panel point.
-4-2024
V0 VAB VBC VCD VD
Shea
r (k
ips)
Peg Shear Diagrams Top Chord
Section - Top Chord
0
1
2
3
4
0.00.51.01.52.02.53.03.54.0
B1
B3
B5
B7
B9
B1
1B
13
B1
5B
17
B1
9B
21
B2
3B
25
B2
7
No
. of P
egs
Bo
tto
m C
ho
rdM
ax. S
hea
r (k
ips)
0
1
2
3
4
0.00.51.01.52.02.53.03.54.0
T1 T4 T7 T10
T13
T16
T19
T22
T25
T28
No
. of P
egs
Top
Ch
ord
Max
. Sh
ear
(kip
s)
L BRIDGE (SYMM.)
C
0
1
2
3
4
0.00.51.01.52.02.53.03.54.0
A1
A3
A5
A7
A9
A1
1A
13
A1
5A
17
A1
9A
21
A2
3A
25
A2
7
No
. of P
egs
Arc
h R
ibM
ax. S
hea
r (k
ips)
Panel Point
Max Shear Force per shear plane (kips) No. of Pegs Figure 6 TA Bridge: maximum shear force per peg
shear plane and no. of pegs at each panel point.
Mode V (peg shear failure)
(Miller, Schmidt, & Bulleit)
TA Footbridge Peg Shear Diagrams
Sh
ear
(k
ips)
4
2
0
2
4
Section – Top Chord
Yield modes of failure for doweled connections
(Timber Framers Guild)
1 2 3
1 2 3
TWO BRIDGES BUILT USING BLACK LOCUST WOOD 25
Elevation
Axial force in lattice members (kips)
AASHTO STR-I combo
Axial force in chords & arch rib (kips)
X
Y
Z
-1.0
-1.3
-2.0
-2.5
-3.2
-5.6
X
Y
Z
60.0
-47.9
-4-2024
V0 VAB VBC VCD VD
Shea
r (k
ips)
Peg Shear Diagrams Top Chord
Section - Top Chord
0
1
2
3
4
0.00.51.01.52.02.53.03.54.0
B1
B3
B5
B7
B9
B1
1B
13
B1
5B
17
B1
9B
21
B2
3B
25
B2
7
No
. of P
egs
Bo
tto
m C
ho
rdM
ax. S
hea
r (k
ips)
0
1
2
3
4
0.00.51.01.52.02.53.03.54.0
T1 T4 T7 T10
T13
T16
T19
T22
T25
T28
No
. of P
egs
Top
Ch
ord
Max
. Sh
ear
(kip
s)
L BRIDGE (SYMM.)
C
0
1
2
3
4
0.00.51.01.52.02.53.03.54.0
A1
A3
A5
A7
A9
A1
1A
13
A1
5A
17
A1
9A
21
A2
3A
25
A2
7
No
. of P
egs
Arc
h R
ibM
ax. S
hea
r (k
ips)
Panel Point
Max Shear Force per shear plane (kips) No. of Pegs Figure 6 TA Bridge: maximum shear force per peg
shear plane and no. of pegs at each panel point.
-4-2024
V0 VAB VBC VCD VD
Shea
r (k
ips)
Peg Shear Diagrams Top Chord
Section - Top Chord
0
1
2
3
4
0.00.51.01.52.02.53.03.54.0
B1
B3
B5
B7
B9
B1
1B
13
B1
5B
17
B1
9B
21
B2
3B
25
B2
7
No
. of P
egs
Bo
tto
m C
ho
rdM
ax. S
hea
r (k
ips)
0
1
2
3
4
0.00.51.01.52.02.53.03.54.0
T1 T4 T7 T10
T13
T16
T19
T22
T25
T28
No
. of P
egs
Top
Ch
ord
Max
. Sh
ear
(kip
s)
L BRIDGE (SYMM.)
C
0
1
2
3
4
0.00.51.01.52.02.53.03.54.0
A1
A3
A5
A7
A9
A1
1A
13
A1
5A
17
A1
9A
21
A2
3A
25
A2
7
No
. of P
egs
Arc
h R
ibM
ax. S
hea
r (k
ips)
Panel Point
Max Shear Force per shear plane (kips) No. of Pegs Figure 6 TA Bridge: maximum shear force per peg
shear plane and no. of pegs at each panel point.
-4-2024
V0 VAB VBC VCD VD
Shea
r (k
ips)
Peg Shear Diagrams Top Chord
Section - Top Chord
0
1
2
3
4
0.00.51.01.52.02.53.03.54.0
B1
B3
B5
B7
B9
B1
1B
13
B1
5B
17
B1
9B
21
B2
3B
25
B2
7
No
. of P
egs
Bo
tto
m C
ho
rdM
ax. S
hea
r (k
ips)
0
1
2
3
4
0.00.51.01.52.02.53.03.54.0
T1 T4 T7 T10
T13
T16
T19
T22
T25
T28
No
. of P
egs
Top
Ch
ord
Max
. Sh
ear
(kip
s)
L BRIDGE (SYMM.)
C
0
1
2
3
4
0.00.51.01.52.02.53.03.54.0
A1
A3
A5
A7
A9
A1
1A
13
A1
5A
17
A1
9A
21
A2
3A
25
A2
7
No
. of P
egs
Arc
h R
ibM
ax. S
hea
r (k
ips)
Panel Point
Max Shear Force per shear plane (kips) No. of Pegs Figure 6 TA Bridge: maximum shear force per peg
shear plane and no. of pegs at each panel point. Computed shear force per peg shear plane
Axial force in chords & arch rib (kips) Axial force in lattice members (kips)
AASHTO Strength-I Combination
TWO BRIDGES BUILT USING BLACK LOCUST WOOD 26
TWO BRIDGES BUILT USING BLACK LOCUST WOOD 27
TWO BRIDGES BUILT USING BLACK LOCUST WOOD 28
TWO BRIDGES BUILT USING BLACK LOCUST WOOD 29
TWO BRIDGES BUILT USING BLACK LOCUST WOOD 30
TWO BRIDGES BUILT USING BLACK LOCUST WOOD 31
TWO BRIDGES BUILT USING BLACK LOCUST WOOD 32
Testing Full-Size Members for Squibb Bridge
(Univ. of Maine)
150 mm diameter x 1.83 m logs
(6” dia. x 72”)
50 mm x 200 mm x 2.49 m beams
(4” x 10½” x 98”)
TWO BRIDGES BUILT USING BLACK LOCUST WOOD 33
Compression
Parallel to Grain n
Ultimate
Compressive Strength
Modulus of
Elasticity
Moisture
Content
Specific
Gravity
Me
an (
ksi)
CO
V (
%)
PT
L
Me
an (
ksi)
CO
V (
%)
MC
(%
)
CO
V (
%)
Me
an
CO
V (
%)
FPL
Wh
ite
Oak
20 3,560 18 2,321 * 1,250 22 Grn - 0.60 10
FPL
Bla
ck
Locu
st
20 6,800 18 4,434 * 1,850 22 Grn - 0.66 10
Sq
uib
b
Bri
dg
e
45 5,219 12.2 4,051 * 1,770 16.2 24.8 17.0 0.61 4.1
TA
Foo
t
bri
dg
e
41 7,156 20.8 4,424 * 1,327 49.5 - - - -
Compression Strength: Two rounds of testing
* PTL = lower 5% at 75% confidence
(ASTM D2915)
TWO BRIDGES BUILT USING BLACK LOCUST WOOD 34
0
5
10
15
20
25
1,0
00
2,0
00
3,0
00
4,0
00
5,0
00
6,0
00
7,0
00
8,0
00
9,0
00
10
,00
01
1,0
00
Co
un
ts
UCS (psi)
0
5
10
15
20
25
1,0
00
2,0
00
3,0
00
4,0
00
5,0
00
6,0
00
7,0
00
8,0
00
9,0
00
10
,00
01
1,0
00
Co
un
ts &
Wei
bu
ll P
rob
abili
ty
UCS (psi)
0
5
10
15
20
25
1,0
00
2,0
00
3,0
00
4,0
00
5,0
00
6,0
00
7,0
00
8,0
00
9,0
00
10
,00
01
1,0
00
UCS (psi)
Block ABlock BCombined WeibullBlock A WeibullBlock B Weibull
Compression Strength: Two rounds of testing
Squibb Bridge
TA Footbridge
Use caution drawing comparisons.
It may not be reasonable to combine the data sets.
≠
