Below are the first 10 and last 10 pages of uncorrected machine-read text (when available) of this chapter, followed by the top 30 algorithmically extracted key phrases from the chapter as a whole.
Intended to provide our own search engines and external engines with highly rich, chapter-representative searchable text on the opening pages of each chapter. Because it is UNCORRECTED material, please consider the following text as a useful but insufficient proxy for the authoritative book pages.
Do not use for reproduction, copying, pasting, or reading; exclusively for search engines.
OCR for page 71
B-1 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
OCR for page 72
B-2 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.
OCR for page 73
B-3 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.
OCR for page 74
B-4 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
OCR for page 75
B-5 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.
OCR for page 76
Figure B14a. Heron Bay results.
OCR for page 77
Figure B14b. Chickasaw Creek results.
OCR for page 78
Figure B14c. Little Lagoon Pass results.
OCR for page 79
B-9 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.
OCR for page 80
Figure B18a. Minnesota Trunk Highway 93 cross section results.
OCR for page 81
Figure B18b. Minnesota Trunk Highway 93 pier 1 results.
OCR for page 83
Figure B23a. Wisconsin State Highway 80 cross section results.
OCR for page 84
Figure B23b. Wisconsin State Highway 80 pier 1 results.
OCR for page 85
B-15 Figure B24. Approach conditions at U.S. 24, Missouri Figure B25. Arc measurement at full extension.
OCR for page 86
Figure B26. Missouri Highway 24 results.
OCR for page 87
B-17 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.
OCR for page 88
B-18 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.
OCR for page 89
Figure B35. Indiana State Route 61 downstream side results.
OCR for page 90
B-20 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.
OCR for page 91
Figure B41a. Ferry Butte results.
OCR for page 92
Figure B41b. West Shelley cross section results.
OCR for page 93
Figure B41c. West Shelley pier results.