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APPENDIX B
FIELD TESTING RESULTS
Colorado Field Testing shoulders to park the truck without additional traffic control
(Figure B9). Cones and signs carried on the truck were used,
The I-70 bridge across the Colorado River in DeBeque and an Alabama DOT vehicle was parked on the approach with
Canyon has three piers on pile caps with 12 H-piles under each its lights flashing. Figure B10 shows a measurement being
pile cap. The total width is 40.5 ft (12.3 m) consisting of two made by sweeping the crane in an arc movement in front of
12 ft (3.7 m) driving lanes, a 10 ft (3.0 m) shoulder on the right, the pier. Multiple arcs were taken to completely map the area
a 4 ft (1.2 m) shoulder on the left and curb sections with Type approaching the pier from the Gulf side.
3 bridge rail (15 inches (0.4 m) wide). The first site visit to this The Chickasaw Bridge is a four-span structure taking State
bridge was made during the week of March 8 as the temporary Highway 213 across Chickasaw Creek in northwest Mobile.
road into the channel was being built for placing additional This bridge is tidally influenced and was rated scour critical
riprap. Some riprap had been placed previously by end dump- based on calculations. There were no shoulders and data col-
ing from the bridge, but Colorado DOT was unable to fill the lection required a lane closure, provided by Alabama DOT.
scour hole completely. Therefore, they were building a rock Figure B11 shows the sonar in place to begin a measurement
road into the channel to allow more direct placement of rock. at a pier. Figure B12 shows the positioning of the stabilizers,
Data collection was attempted during this first trip using the with one on the deck and one on the curb.
crane system, but the computer kept locking up. This may have The Little Lagoon Pass Bridge is a six-span bridge on State
been caused by a cell phone tower just upstream of the bridge Highway 180 near Gulf Shores, Alabama. The bridge is in a
scrambling some of the data during wireless transmission from constricted tidal inlet that historically has had significant sed-
the end of the crane. The software was subsequently modified iment movement and relatively high velocities because of the
to filter for bad data, and on a return trip during the last week constriction created by the seawalls. The bridge has had some
of March, data were collected on both the upstream and down- scour problems because of the velocities, while the entire
stream sides of the bridge from Pier 2 to the right abutment bridge reach in the inlet area has had sediment deposition prob-
(defined looking downstream). Colorado DOT provided traf- lems, requiring dredging. Alabama DOT had expected rela-
fic control during both trips. tively high tidal velocities at this bridge, but after several hours
Data was collected on the downstream side by positioning of waiting on the bridge for the cross over point between low
the bridge to the right of the pier where the scour hole had been and high tide, when the velocities would be highest, measure-
and sweeping multiple arcs (Figure B1). Data were collected ments found the maximum velocities on this day to be about
on the upstream side with the truck positioned at the centerline 3 fps (0.9 m/s). Velocity measurements were made with a
of Pier 2 and about midway between Pier 2 and the abutment Marsh-McBirney current meter attached to the end of the crane
(Figure B2). Figure B3 shows the articulated arm being low- (Figure B13). For this bridge, the extension was taken off the
ered into position. The instrument shelter with the computer sonar to allow mounting the current meter as shown. The veloc-
and other instrumentation is shown in Figure B4, as is one of ities and stream power were high enough to create ripples and
the two post-mounted winches. The instrument box at the end some dune movement of the bed but no significant scour at the
of the crane is being wired for operation in Figure B5. Fig- piers.
ure B6 shows one of the two winches being used to suspend Figures B14a through c provide plots of the data collected
the sounding weight, and the Marsh-McBirney velocity sensor at these bridges.
on a 50-lb (24-kg) weight is shown in Figure B7.
Based on the data collected, a plot of the bathymetry was
developed for the area upstream and downstream of Pier 2 (Fig- Minnesota Trunk Highway 93 Bridge
ure B8). CDOT was interested in the riprap placement, because
it had to be done underwater in high-velocity conditions. Based Minnesota Trunk Highway 93 (TH93) crosses the Min-
on the bathymetry, the scour hole was filled with rock. nesota River near LeSueur, Minnesota. The bridge has five
spans on four piers on a pile foundation. The total width is
46 ft, 2 in. (14.1 m) consisting of two 12 ft (3.7 m) driving
Alabama Bridges lanes, two 9 ft, 5in (2.9 m) shoulders and an 18 in. (0.46 m)
barrier railing.
Three bridges were visited in the Mobile, Alabama, area. Given the drought conditions in Minnesota, the bridge was
The Heron Bay Bridge, a five-span bridge on State Highway visited primarily to demonstrate the equipment to Minnesota
193 leading to Dauphin Island, is scour critical based on cal- DOT and to complete initial testing of components that had
culations. The bridge is a two-lane structure with wide-enough been modified since the Alabama trip. This included the new
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Figure B1. Crane on downstream side of bridge near
scour hole.
extension for the sonar stabilizer with the pivot point further
forward on the blade and the new castor system for cross-
section measurements. At the time of the inspection, runoff
was low and there were no known scour problems. The inspec- Figure B3. Looking down the articulated arm as the
tion was completed on May 13, 2002, and included arc mea- sonar is being positioned in the water.
surements at Pier 1 and a cross section on the upstream side
of the bridge. Minnesota DOT provided traffic control.
Figure B15 shows the truck in position to measure condi- lowered, takes only minutes to deploy. Figure B17 shows the
tions at Pier 1. The new stabilizer blade performed well and truck ready for a cross-section measurement, with the castors
was able to track the current, even given low-velocity condi- in place and the surveyor's wheel on the ground.
tions. Figure B16 shows the improved castor system used to Figure B18 plots the data collected at these bridges.
allow truck movement with the crane deployed. This system
was not quite as rigid as the original turnbuckle design, but Wisconsin State Highway 80
was much easier to deploy. The turnbuckle system took about
30 minutes to set up, while the new system, with the castor on Wisconsin STH 80 crosses the Wisconsin River near
an arm that can swing in place under the outrigger before it is Muscoda, Wisconsin. The bridge has nine spans on eight
Figure B2. Using the articulated arm to sweep arc's on
the upstream side of bridge. Figure B4. Collecting data.
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Figure B5. Instrument box on end of crane. Figure B7. Marsh-McBirney velocity sensor on a 50 lb
sounding weight.
hammerhead piers supported by spread footings. The total tions at the pier. The inspection was completed on May 14,
width is 42 ft (12.8 m), consisting of two 12 ft (3.7 m) driving 2002, and included arc measurements at Pier 1, a cross sec-
lanes, two 6 ft (1.8 m) shoulders, and 18 in. (0.46 m) parapets. tion from Piers 1 to 3, and kneeboard measurements to get
The bridge has had scour problems at Pier 1, which is in further under the bridge deck at Pier 1. Wisconsin DOT
an eddy along the left bank creating reverse-flow condi- provided traffic control.
Figure B19 shows the sonar in the water on the upstream
side of Pier 1. Note the orientation of the stabilizing fin in Fig-
ure 20, which indicates the reverse-flow condition at this pier.
Figures B20 through B22 illustrate the deployment of the
kneeboard on a rigid frame to get under the bridge. The frame
was made of aluminum and connected to the rotator on the end
of the crane. Knowing the location of the end of the crane, the
angle of the rotator, the length of the frame, and the distance
to the water surface, personnel can calculate the position of the
kneeboard as it is moved under the bridge.
During this field trial, as the kneeboard was being swept
side-to-side under the bridge with the hydraulic rotator, the
frame was bent as the flow line between the main flow and the
reverse flow was crossed. A software problem was also dis-
covered in the position calculation for this method during this
test. A stiffer, simple frame was designed after this event and
the software was revised, prior to additional testing in Idaho
Figure B6. Using a single winch to position sounding (see below).
weight with Marsh-McBirney. Figure B23 plots the data collected at these bridges.
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Figure B8. Colorado I-70 results.
Figure B9. Heron Bay bridge, Highway 193 near Figure B10. Making an arc measurement on the Gulf side
Daulphin Island. of the bridge.
Missouri U.S. Highway 24 The inspection was completed on May 17, 2002. Missouri
U.S. Highway 24 crosses the Grand River near Brunswick, had received significant rainfall in the week prior to the inspec-
Missouri. The bridge has seven spans on six piers, two of tion, but most of the smaller drainages had already peaked.
which have been protected with gabion baskets because of After visiting several bridges around the Macon area that were
scour problems. The bridge is about 47 ft (14.3 m) wide, with on smaller drainages and finding little flow in the channels, this
two 12 ft (3.7 m) lanes, two 10 ft (3.0 m) shoulders and 18 in bridge was selected to evaluate the performance of the gabion
(0.46 m) barrier rails. baskets during and after a large flow event. The Grand River
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tracted for removal. In addition to potential pier scour during
the recent high flows, Indiana DOT was particularly inter-
ested in seeing if the sand bar was still present and asked that
the research team survey both the upstream and downstream
sides of the bridge.
Figure B27 depicts the bridge deck, which was 48 ft, 4 in.
(14.7 m) wide, with 12 ft (3.7 m) lanes, 10 ft, 8 in. (3.2 m)
shoulders, and 18 in. (0.46 m) concrete barrier wall. Traffic
control was provided by Indiana DOT. Figure B28 illustrates
conditions on the upstream side of the bridge.
Figure B29 shows the cross-section measurement being
taken on the upstream side, and Figure B30 shows the sonar
in the water as the measurement is being made. The truck had
to be positioned away from the concrete barrier to avoid run-
Figure B11. Crane in position at the Chickasaw Bridge. ning the castors over the drainage inlets (Figure B31). How-
ever, this did not create a problem as the arm was articulated
into an acceptable position for the cross section. Figure B32
watershed is large, and flow conditions were still quite high at shows an arc measurement on the downstream side of the
the time of inspection, with velocities around 7.0 fps (2.1 m/s). bridge. Note the wake indicating the strength of the current,
Based on the time available and a large debris snag at Pier 6, which was flowing about 6.8 fps (2.1 mps).
measurements were completed only at Pier 5. The wireless sonar mounted in a 75 lb (34 kg) sounding
Figure B24 shows the approach conditions to the bridge. weight was tested at this bridge. The sounding weight was sus-
Figure B25 illustrates an arc measurement at full extension. pended by a 4 ft (1.2 m) hanger bar with the electronics (wire-
Figure B26 plots the data collected at these bridges. less modem) enclosed at the top of the hanger bar (Figure B33).
The sonar is embedded in the bottom of the sounding weight,
Indiana State Route 61 with a small wedge to better transition flow over the transducer
face (Figure B34). This was necessary given that most sound-
Indiana S.R. 61 crosses the White River southeast of ing weights are not streamlined on the bottom, but are designed
Vincennes, Indiana. The bridge has five spans on piers with with a flat bottom so they are stable when set on the ground for
pile caps with steel H piles driven to approximate refusal. rigging current meters. The flat-bottom design could create a
The bridge was designed for a 100-year flow of 114,810 cfs separation zone off the nose of the sounding weight, which
(3,250 m3/s). At the time of inspection, May 22, 2002, the would not be an issue for current meter applications but was a
river was at flood stage, and the southern part of the state concern when mounting a sonar transducer in the bottom of the
was experiencing the wettest May on record. weight.
The bridge has not had any major scour problems, but had Figure B35 plots the data collected at these bridges.
a large sand bar in the bridge opening that had been con- (text continues on page B-9)
Figure B13. Marsh-McBirney current meter mounted on
Figure B12. Positioning the stabilizer on the curb line. the crane upstream of the sonar.
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Figure B14a. Heron Bay results.
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Figure B14b. Chickasaw Creek results.
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Figure B14c. Little Lagoon Pass results.
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Idaho Bridges
Two bridges on the Snake River were visited near Black-
foot, Idaho. The drought conditions limited runoff in the state,
particularly in eastern Idaho; however, these bridges have had
scour problems in the past and were of interest to Idaho DOT.
Additionally, they were going to install A-jacksTM as a coun-
termeasure later in the year and were interested in having a sur-
vey prior to construction. Both the Ferry Butte Bridge, south
of Blackfoot, and the West Shelley Bridge, north of Blackfoot,
were visited on June 4, 2002.
The bridge design for both structures is similar, with four
spans on spread footing piers. The deck width was 33 ft
(10.1 m) with no shoulder, requiring a lane closure for traf-
Figure B15. Making measurements at Pier 1. fic control that was provided by Bingham County. Arc mea-
surements were made at the upstream side of the piers at both
bridges, supplemented by kneeboard measurements at Ferry
Butte and a cross section at West Shelley.
Given narrow bridges with no shoulder, placement of the
truck on the bridge deck at these bridges (Figure B36) was
similar to the Chickasaw Bridge in Alabama. Figure B37
shows an arc measurement in process on the upstream side.
After problems with the kneeboard frame in Wisconsin, a
revised frame was developed. The revised frame was made of
steel (the original was aluminum) and was more rigid and also
allowed the kneeboard to swivel, similar to the concept used
on the sonar stabilizing fin. The frame was tested at the Ferry
Butte Bridge and worked better than the original design, but
the kneeboard/frame was still somewhat difficult to get ini-
tially placed in the flow and then pushed under the bridge. Fig-
ure B38 shows the kneeboard along side the pier wall at the
Figure B16. Close-up of stabilizer sitting on castor. bridge. The software revisions made after the Wisconsin bridge
to calculate the position of the kneeboard did correct the posi-
tion problems that existed.
Figure B39 shows an arc measurement near a pier at the
West Shelley Bridge. Even at low flow, the local velocity and
turbulence near the piers were significant. An accumulation
of gravel and sand along the curb line on this bridge was a
concern in terms of the castors during the cross-section
measurement, but the neoprene wheels rolled through this
material with no problems (Figure B40).
Figure B41 plots the data collected at these bridges.
Figure B17. Cross section measurement with castors
deployed and survey wheel in place to measure distance
traveled.
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Figure B18a. Minnesota Trunk Highway 93 cross section results.
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Figure B18b. Minnesota Trunk Highway 93 pier 1 results.
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Figure B23a. Wisconsin State Highway 80 cross section results.
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Figure B23b. Wisconsin State Highway 80 pier 1 results.
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Figure B24. Approach conditions at U.S. 24, Missouri
Figure B25. Arc measurement at full extension.
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Figure B26. Missouri Highway 24 results.
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Figure B27. SR 61 crossing the White River in Indiana. Figure B29. Measuring a cross section at SR 61.
Figure B30. Sonar in the water as the truck is moving
Figure B28. Upstream conditions at S 61. across the bridge during a cross section measurement.
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Figure B31. Truck positioned to clear grate during cross Figure B33. Sounding weight with sonar.
section measurement.
Figure B34. Close up of sounding weight showing wedge
Figure B32. Arc measurement on downstream side. on leading edge of sonar.
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Figure B35. Indiana State Route 61 downstream side results.
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Figure B36. Truck placement at Ferry Butte.
Figure B37. Arc measurement on upstream side. Figure B39. Arc measurement upstream at West Shelley.
Figure B40. Castor movement through sand and gravel
Figure B38. Kneeboard under bridge at Ferry Butte. deposited along curbline.
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Figure B41a. Ferry Butte results.
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Figure B41b. West Shelley cross section results.
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Figure B41c. West Shelley pier results.
