Cranes Roost Park Facility Analysis

Transcription

1 Cranes Roost Park Facility Analysis Summary Report Altamonte Springs, Florida GAI Project Number: A September 2013 Prepared for: 225 Newburyport Avenue Altamonte Springs, Florida Prepared by: GAI Consultants, Inc. Orlando Office 618 East South Street, Suite 700 Orlando, Florida 32801

2 Page i Table of Contents Executive Summary... 1 Purpose Project Team and Roles Inspection Operations Dive Inspections Above-Water Inspections Floating Stage East Boardwalk East Overlook West Boardwalk Amphitheater Seawall West Seawall Limitations of Investigation Conclusion... 6 Attachments 7 A Figures and Photos... 7 B DVD Index... 7 C UESI Dive Inspection Report... 7 C Photo Contact Sheet... 7 Attachment A Figures and Photos Attachment B DVD Index Attachment C UESI Report 2013 GAI Consultants, Inc.

3 Page 1 Executive Summary The various structures are in generally fair to good condition, with specific minor to moderate problems. No major issues or unforeseen conditions were found. Some structures will require a moderate level of rehabilitation to maintain their capacities; others will need only minor repair and maintenance. A. The Floating Stage was found to be in better condition underwater than above. Minor to moderate rehabilitation will be recommended. Overall it is in good condition. The tensile fabric canopy was not addressed. The vertical deflection in the deck was judged to be due to slight rotation of the float-to-frame bolted joints. The anchoring system was found to be in poor condition and several cables were re-connected to the anchor slabs in the course of the dive inspections. We strongly recommend re-design of the anchor system. B. The East Boardwalk is in fair condition. It has some deterioration, especially in metal connectors that must be addressed within one (1) year. Wood members were in good condition with some areas of minor decay. Minor to moderate rehabilitation is recommended. C. The West Boardwalk is in good condition. It also has some metal connector corrosion that is similar to the East Boardwalk but not as widespread. Wood members were also found to be in good condition overall. Some metal connectors must be replaced within two years, and other minor to moderate rehabilitation is recommended. D. The Overlook wood structure is similar to the East Boardwalk, and in fair to good condition. The work recommended is similar to the East Boardwalk. E. The Amphitheater Seawall appears to be in very good condition, with no visible signs of erosion or other issues. No work is required now, other than periodic inspection. F. The West Seawall is in good condition, with no signs of erosion or other issues. We recommend inspection of the storm pipes and a sounding survey for silting. The wall itself requires no work at this time. Individual reports at Tabs 2 through 7 make recommendations and identify options for the repairs at different levels of response. These are broken down as follows: Option A. No action. In some cases, this is a not a viable option. In other areas it is viable and a desirable option. The longevity associated is listed. Option B. Moderate repairs. Minor to moderate level of repair or rehabilitation to achieve reasonable longevity. Option C. Full repairs. Major level of repair or rehabilitation to achieve a maximum life span. These reports and recommendations are based on thorough investigations of each structure that included mainly visual and tactile observations and non-destructive inspection methods. At the timber bridges, destructive testing was performed by coring wood samples at 10% of the bents. Lifting the deck boards at these locations allowed us to estimate the condition of the hidden portions of the wood framing. Every structure was inspected above and below water and from below deck by float or canoe. Although there are some inaccessible areas and surfaces, the readily accessible areas were examined as thoroughly as possible within reasonable facility downtime and within a reasonable budget. The investigations also included gathering historical data on each structure from interviews with Park staff and from the drawing records provided by the City.

4 Page 2 Purpose This memorandum is to give a brief summary of the inspection work and observations made by the GAI Inspection Team for each of the structures in this project. The observations have taken place in June, July, and August 2013 and included above-deck inspections, through-deck inspections, inspections from boats and floats, and underwater dive inspections. Most of the observations were visual, supplemented by sounding hammer, ice pick probes, increment borer, and other tools and sampling. The following sections summarize the observations on the six structures that were inspected. See Figure 1 in Attachment A for an aerial view of the structures. A Floating Stage B East Boardwalk C West Boardwalk D East Overlook E Amphitheater Seawall F West Seawall 1.0 Project Team and Roles The GAI Team consisted of GAI Consultants, Inc. Underwater Engineering Services, Inc. (UESI), CEC General Contractors, Inc., and Sun State Technical Services, Inc.. Their roles were as follows, with some beneficial overlap in expertise. GAI GAI provided overall project planning and professional engineering responsibility, including structural engineering, bridge inspection expertise, structural and dynamic analyses, overall safety plan, and consolidated reporting for all structures. GAI s experience with stage barges, seawalls, timber bridge inspection, and marine terminals, helped tie together a variety of structures and subconsultants. UESI These underwater experts, led by Marty Faulk, CBI, performed all dive inspections for the 6 structures. They examined for damage, coatings integrity, and corrosion level, soundness of timber, and scour checks. They provided direct communication between the above-water inspectors and the diver, as well as underwater video recording to document all observations. Marty reviewed and contributed to the reports. In addition to the original scope of work, UESI made repairs to one anchor assembly and attempted repair of a second, with the help of the Park staff. CEC - A marine construction specialist, president John Dinsmore provided detailed knowledge of the original Floating Stage construction; in addition, having built hundreds of timber bridges and miles of seawalls throughout Florida in fresh and salt environments, John contributed suggested repair methods for the timber structures and ideas for re-design of the Stage anchor system. He reviewed and contributed to the reports. Sun State Technical Services, Inc. Norman Lesmerises performed a complete Marine Survey of the Floating Stage vessel. Norm was working with Mr. Stephen Felder at the outset of this project, and when Mr. Felder took a project for a California theme park, Norm took over the responsibility here. He has designed floating stages, performance barges, fireworks platforms, and modifications to entertainment vessels. He has conducted marine surveys on a wide variety of other vessels. He reviewed and contributed to the Floating Stage Report, and his marine survey report is appended to it. Cranes Roost Park Staff The Park staff, headed by Chief Ranger Bill McCombs, was indispensable in providing more than just the background information and maintenance history of the structures. The

5 Page 3 rangers helped at every stage, starting with providing floats and canoe for inspectors to access the water side of the structures. They operated Park boats for the 3 days of dive inspections for Structures B through F, pushed floats into position at the bridges on other days, and opened up 24 locations on the timber bridges by removing deck boards (see Figure 2). This was more difficult than expected, as the boards are obstructed by the handrails and light poles, and the screws are very long and brittle. Many screws were already broken or sheared off during the work, they had to be cut out with great difficulty. For the repairs to the anchoring system, Bill McCombs somehow found parts overnight. When the daily heavy rains eventually killed the dive power generator, the Park staff rescued the day with a back-up generator. 2.0 Inspection Operations All team members participated in the planning stage and safety plans. The above-water Boardwalk inspections were performed by GAI personnel James Simpson, Senior Bridge Inspector, Janine Pardee, P.E.; and Ed Wartalowicz, P.E. (see Figures 3 to 7). John Wise and Chris Cuthill of GAI Survey provided survey of the Floating Stage and helped with bridge inspections. The above-water Floating Stage inspections were conducted by Janine Pardee and Ed Wartalowicz, plus John Dinsmore and Norm Lesmerises. The underwater inspections were conducted by UESI s dive team, headed by Marty Faulk, Certified Bridge Inspector. The individuals who made the inspections contributed to the report findings, sketches, photos, and drawings. It was important to keep the field work on schedule and on budget. There were many parties involved and schedule changes would complicate everyone s business. The budgets were fixed and tightly planned. The project team worked efficiently together and the inspection work was accomplished very much according to plan. There were some hitches, but thanks to team cooperation and the Park staff support, these did not affect the outcome. The dive inspectors were not able to launch their covered work boat due to its long length and the overland approach to the launch ramp on the north shore. The Park staff then provided a small launch with a Bimini top for 2 days of the dive inspections. This was fortunate as there were storms and light rain throughout the dives that would have damaged the video and communications equipment. We would have been unable to continue the work without the light canopy covering the equipment. The inspection work was affected by the weather in several ways. The lake level became very high due to summer rains, and the East Boardwalk was nearly submerged. It took several days before the underside was accessible, and even then inspector Jim Simpson had to lay flat on a float for much of that work. The above-water inspections were interrupted by rain a few times; henceforth we changed to a mainly morning schedule. Because of the planning and expertise of the various team members, and the backup provided by the City, all of the planned inspection targets were accomplished. The diverse backgrounds overlapped well and the team worked smoothly together through thunderstorms, high water, and minor difficulties. In spite of factors like tight time windows, weather factors, almost-zero water clarity, and tight quarters, all inspection goals were achieved with excellent results. 3.0 Dive Inspections The dive inspections were conducted over 3 days on July 22, 23, and 24. Underwater Engineering Services, Inc. (UES) performed the dive work, with Marty Faulk, CBI, as Lead Bridge Inspector. GAI engineers, Janine Pardee, PE, and Jim Simpson, Senior Bridge Inspector, were onsite to coordinate and observe all the dives of the various structures. In addition, Norman Lesmerises, Certified Marine Surveyor, was on hand to conduct the marine survey of the Floating Stage and to observe the dive inspection of that structure (see Figures 8 to 12).

6 Page 4 The dive inspections moved according to plan, except for weather downtime. The dives were stopped 3 times due to thunderstorms, and resumed when the hazardous conditions were cleaned. All dives were video-recorded except for parts of the extra dives to repair to the anchor system. DVD copies of these recordings are submitted with this report. These include the video recorded at the helmet-mounted dive camera and the audio communication and commentary from both the dive inspector and the surface dive master. The audio is important because of the limited visibility of the lake water; one cannot follow the video with its intermittent view of the surfaces, without the commentary of the diver and the dive master. There was a substantial communication with the abovewater inspectors, each of whom was on-hand to observe and ask questions in the dive inspection of their particular structures. All inspectors found the dive inspections to be very successful in identifying conditions underwater, answering questions raised by the above-water inspections, and documenting the findings. The report submitted by UESI is appended to this report for reference at Attachment C. 4.0 Above-Water Inspections All structures were examined from their walk surfaces first, and then from the surface by float or canoe. The Park staff provided a small floating dock and towed it into place for the East and West Boardwalks and the East Overlook. Then Jim Simpson of GAI, who headed the bridge inspections, moved the float by hand from bay to bay. Because of the high water experienced in June, the East Boardwalk float inspection was delayed until after the 4 th of July. Even then, inspector Simpson had to lay on his back to pass under parts of the structure. Other GAI engineers observed and conducted portions of the inspections. Janine Pardee, PE and Ed Wartolowicz, PE, made an overall walk-thru of all structures in the interest of the load ratings reports. Pardee observed most of the dive inspections, inspected the seawalls by canoe, and reviewed all bridge deficiencies in the field with Jim Simpson. 5.0 Floating Stage The Floating Stage is in good condition, with a few areas of moderate to severe corrosion. The general conditions and main patterns of deterioration are: 1. The deflection noted in the perimeter was found to be the result of structural deflection and not the result of damage. It is due to the high flotation at the corners and relatively low flotation at the middle, combined with the high tensile loads from the canopy. 2. The dive inspection revealed that the submerged surfaces and coatings are in good condition, with minor exceptions. 3. The superstructure has moderate to severe corrosion at the column bases socket connection. 4. The bolted connections of the aluminum floats to the steel main frame range from light to severe corrosion. 5. The canopy support superstructure has some minor corrosion spots and moderate corrosion of cables and fittings. 6. The anchoring system is in fair to poor condition. It is problematic and should be re-designed. Minor to moderate work is recommended for the Floating Stage, except that we recommend the anchoring system be totally redesigned so that the Stage is not trapped in one position.

7 Page East Boardwalk The East Boardwalk bridge is in fair condition overall, with specific patterns of deterioration that need to be treated to achieve best longevity. Moderate work is required within one (1) year. The East Boardwalk has been submerged several times since it was built. These submersion events and its slightly greater age have caused this bridge to deteriorate more than the West Boardwalk. The general conditions and main patterns of deterioration are: 1. Severe corrosion of sheet metal timber hangers and connectors has occurred at the Observation Decks. Many of the U-shaped connectors have corroded completely through so that the bottom is gone. 2. Moderate to severe corrosion of steel bolts at the beam-to-pile connections and other locations. 3. Moderate to severe decay in the tops of most piles. The centers of the timber piles are usually decayed to a depth of 4- to 8-inches in a diameter of about 6-inches of the heart material. 4. Light to moderate decay in the tops of about 5% of the wood beams and joists. Occasional severe decay has occurred in joists in contact with soil or tree debris. 5. Deck boards are generally in good condition. A few screws are too high or missing. Several deck boards have high spots, and several fascia boards are loose. 6. Handrails and canopy superstructures are generally in good condition, with minor deterioration such as rust spots, fastener corrosion, and other minor defects. 7. The submerged portions of the piles are generally in sound condition. One pile has sunk about 3, so the connecting joists and deck have a deflected area. This requires some repair. 8. At the Observation Decks, the longest joists have developed permanent sags of 2- to 3-inches. There will be moderate repairs needed within one (1) year in order to maintain the full capacity of this bridge. The detailed report contains specific recommendations. 7.0 East Overlook The Overlook structure just west of the East Boardwalk has similar conditions and issues. It is in generally fair to good condition, except for similar deterioration like items 1, 2, 3, 4, and 8 above. It requires minor to moderate repairs within one year to maintain its full capacity. 8.0 West Boardwalk The West Boardwalk bridge is in good condition, except for some deterioration of the metal connectors. The patterns of deterioration are similar to the East Boardwalk but are less advanced. This bridge has a higher deck elevation and has not been submerged. However, it still experiences the day-to-day moist environments of the lake and therefore has some of the associated degradation. The general conditions can be summarized as follows: 1. Some of the sheet metal timber hangers are moderately corroded. 2. Some of the steel bolts attaching the beams and piles are moderately corroded. 3. The tops of some piles have center decay about 2- to 4-inches deep. 4. There is light decay in the top surfaces of some of the wood beams and joists. 5. The deck boards are in generally good condition. Some screws need to be adjusted or replaced. 6. Handrails and canopy structures are in good condition except for some minor corrosion.

8 Page 6 7. The submerged portions of the piles are generally in sound condition. 8. At the Observation Decks, the longest joists have developed permanent sags of 2- to 3-inches. 9. There are missing bolts at several steel clips at the Observation Decks. Minor to moderate repairs will be needed within two years in order to maintain the full capacity of this bridge. 9.0 Amphitheater Seawall This seawall supports the walkway along the waterfront and forms part of the amphitheater. It is a steel sheetpiling wall covered by concrete decorative panels. The seawall is in good condition to the extent that the steel sheetpiling could be observed. There is no evidence of soil pumping or erosion of the fill soil behind the wall. The concrete panels and the concrete pile cap are in good to very good condition. No work is required at this time. The seawall should be visually inspected from the decks and by canoe, every 2.5 to 5 years. If deficiencies are found in the future, an underwater inspection can be made West Seawall This seawall supports the roadway, the faux bridge and a paved overlook area at the Tower. It is steel sheetpile covered by concrete decorative panels identical in cross-section to the Amphitheater Seawall. This seawall also appears to be in good condition in the portions that could be observed within 5 feet of the seawall. No accumulations of soil were found nearby or any washouts or erosion. The concrete pile cap and the concrete panels are in good to very good condition. There are two or more drainage culverts that let out through the wall under the concrete overlook structure. Sand bars or accumulations of soil that have been observed during low-water periods may be due to the drainage of these storm outlets. For this reason we recommend a survey to determine if the drainage pipes are silting-in. It may be found that an inspection of the pipes will be needed Limitations of Investigation Every inquiry is limited in various ways, and some of the general limitations of this investigation are listed below. The following limitations, disclaimers, and exclusions apply to this report and the investigation of this matter. This examination was limited to visual observation and measurement of the visible, accessible portions of the structure. No destructive testing, non-destructive testing, exploration, structural analysis, calculations, or sampling were performed except as described herein. Observations are based on the conditions existing at the time of inspection. Conditions will change with time. Based upon my knowledge, information, and belief, and using commonly-accepted procedures and standards of practice, it is my opinion that the recommendations and conclusions listed in this document are accurate and appropriate for this structure to within a reasonable degree of engineering certainty. This examination and report and the opinions expressed do not constitute a guarantee or warranty, either expressed or implied Conclusion

9 Page 7 The 4 main park structures are in good condition for their 20 years of age. They need minor to moderate rehabilitation to extend their useful life and reduce future maintenance. The 2 seawalls are in good condition and no work is needed. Periodic visual inspections every 2 ½ years are recommended for all structures to intercept any developing problems. More detail is presented in the individual reports for each structure. GAI and its team of subconsultants are available to meet with the City to review the findings and recommendations. Please do not hesitate to call if there are any questions on this report or the inspection work. Respectfully submitted, GAI Consultants, Inc. Janine Pardee, PE Senior Engineering Manager Attachments A B C C Figures and Photos DVD Index UESI Dive Inspection Report Photo Contact Sheet

10 ATTACHMENT A Figures and Photos

11 Figure 1. The six structures investigated are shown in this aerial plan. Figure 2. The Park staff removed decking at a number of bridge bents for closer inspection and sampling.

12 Figure 3. Wood samples were pulled from the most decayed joist or beam. Figure 4. A 4 inch Haglof Increment Boring Bit was used to pull wood cores.

13 Figure 5. Wood cores were examined and measured. Figure 6. Another important wood inspection tool is a tapered pick to find depth of decay.

14 Figure 7. The bridges were inspected from a float provided by the Park staff. Figure 8. Dive inspections started with the Floating Stage. Monitoring equipment is in the foreground; diver and helper beyond.

15 Figure 9. On top of the diver s helmet are a light and video camera. There is a microphone in the faceplate. Figure 10. For the other structures, the dives were conducted from a Park skiff.

16 Figure 11. Monitoring equipment was sheltered from rain under the bimini top. Figure 12. The above-water inspectors were able to watch the dive inspections and ask questions in real time.

17 ATTACHMENT B DVD Index

18 Dive Inspections and DVD Index Monday, July 22, 2013 Day 1 DVD = Floating Stage Part 1 Main Steel Pipe Frame and Connections (2:25) (Stormed out by lightning twice at 3 pm and 5 pm.) Tuesday, July 23, 2013 Day 2 DVD 1 = Floating Stage Part 2 Aluminum Flotation Units 07:38 am Anchor Inspection and Repair Attempt 09:00 am (1:57) (Stormed out by lightning at mid-day.) Day 2 DVD 2 Track 1 - Structure D - Overlook 12:19pm (0:22) Track 2 - Structure B - East Boardwalk Bent #35 12:49 pm (0:05) Track 3 - Structure A - East Boardwalk Overall 13:10 pm (1:57) Day 2 DVD 3 - Structure A - Anchor Repair Second Attempt 15:31 pm (1:02) Wednesday, July 24, 2013 Day 3 DVD 1 - Structure C West Boardwalk Track 1 2:19 Bents 2 to 48 Track 2 0:14 Bents 49 to 50 Track 3 0:18 Bents 51 to 58 Track 4 0:22 Bents 59 to 71 Day 3 DVD 2 = Seawalls Track 1 0:25 Seawall at Amphitheater, east half Track 2 0:14 Seawall at Amphitheater, west half Track 3 0:57 Long Seawall at Faux Bridge to Overlook at Tower to west end of seawall (Rain throughout day, no lightning.) Remarks and Notes on DVD Observations The water clarity is very low, and the visibility is limited to about 1 foot. So, all video images are very close to the divers mask. Unless one follows the entire sequence and listens to the diver comments, it is very difficult to know where the diver is located on the particular structure. There are no overview shots as only green cloudy water can be seen. The color is not correct, due to the artificial light, and discoloration of the water from dyes and particulates. The picture is color-corrected but still appears somewhat greenish. When the diver surfaces all video looks blue. The clock on the video recording is about 1 hour 15 minutes behind actual EDST at the time of inspection. For instance, the Day 2 DVD 3 started at 16:49, but reads 15:31.

19 A. Floating Stage The surfaces that are flat and striated (striped-looking) are the aluminum floats. When shiny metal is seen it is aluminum, usually alum clips attaching floats to clips on steel pipe. Curved surfaces are the 4 ft diameter pipes making up the main frame. All surfaces have algae deposits. Where surfaces appear white, they are usually the painted steel. The inspection proceeded with the main frame on the first dive, from bow to stern (left to right when looking from shore). The next day, the inspection covered the floats, following a similar pattern. During the anchor inspection and repair attempts, the stirred-up bottom matter so clouds up the picture that very little can be seen. B. East Boardwalk The beams were half-submerged at the time of the inspection. C. Overlook The Overlook was partially in the water when inspected. The joists were clear, but the beams below were half-submerged. D. and E. Seawalls Very little can be seen except the occasional clip attachment of concrete panels to steel sheetpiling. Both inspections started at the east end of the walls and proceeded west. They were interrupted briefly at the middle to move the diver and lines to the far side of the obstructing docks or structures. Dive Team 1. Marty Faulk, Dive Master and Certified Bridge Inspector 2. Chris Peterson, Diver 1 3. Alex Kraeger, Diver/Helper 2 The original DVD s are retained by UESI, and GAI has 1 copy of each.

20 ATTACHMENT C UESI Dive Inspection Report

21 EXECUTIVE SUMMARY The underwater inspection of the structures at Cranes Roost Park found the structure elements to be generally sound and free of defects. There were no major or significant defects observed that would have required immediate attention. The Floating Stage anchoring system is in need of repair or redesign. Two areas had minor damage and will require maintenance in the near future to prevent a reduction of their service life. The connection bolts for the Floating Stage were found to have minor corrosion scale and will require recoating. Areas of the Floating Stage adjacent to the anchors had abrasion damage (coating failure and minor section loss) due to chaffing from the anchor cables. The timber piles of the boardwalks and overlook platform were found to be sound with no signs of damage. The channel bottom had no significant debris and no signs of scour. INTRODUCTION The developed Cranes Roost Park in the 1990's, constructing the amphitheater, walkways, and East Boardwalk in The West Boardwalk and Floating Stage were added in UESI was selected to perform the underwater inspection portion of the project as a sub consultant to the prime consultant, GAI. This report presents the observations and results of the underwater inspection. Purpose and Scope The purpose of the project was to assess and evaluate the existing condition of the underwater portions of the Floating Stage (Structure A), the East and West Boardwalks (Structures B and C), the Overlook (Structure D), and the piles and walls of the Amphitheater Seawall and West Seawall (Structures E and F). Specifically, the Floating Stage had an apparent sag condition resulting from elevations taken on its deck. UESI was requested to take a close look at any potential failures or signs of distress that could be causing the apparent sag. The scope of work consisted of providing all necessary equipment and personnel to perform an underwater inspection of Structures A through F as described above, that consisted of the floating elements and anchoring cables of the Floating Stage, and all substructure elements (piles and walls) of the other structures. The work included live video feed topside for a GAI engineer to monitor the

22 observations. The scope of work included a Level I (visual and tactile) inspection of 100% of the underwater portions of the structures. A level II inspection (removal of marine growth and closeup visual) was performed on 10% of the boardwalk piles. This included sounding and awl penetration observations. General Description of Structures Floating Stage The Floating Stage is a United States Coast Guard registered vessel constructed of structural steel with an aluminum and steel superstructure with floatation cells and a timber deck. This structure is approximately 55 ft wide by 120 ft long. The prefabricated aluminum sections and the 48-in.- diameter carbon steel pipe trusses were filled/injected with urethane foam for flotation purposes. The Floating Stage is secured to the lake bottom by a method of electric winch/cable anchoring systems. These systems consist of 3/8 in. stainless steel cable attached to a winch drum that is attached to the carbon steel pipe truss brackets. The cables are routed through a spreader bar pulley system located on the concrete slabs on the lake bottom. East and West Boardwalks The East and West Boardwalks are pedestrian bridges approximately 12 ft wide by 520 and 980 ft long, respectively. They are comprised of timber piles, timber beams and timber joint framing with timber decking. The pile bents each have two 12-in.-diameter piles. There are 40 and 72 pile bents for the East and West Boardwalks, respectively. Overlook and Amphitheater The Overlook substructure is comprised of 10 each 12-in.-diameter timber piles. The Amphitheater Seawall is comprised of approximately 390 ft of seawall comprised of steel sheetpiling and decorative precast concrete panels. DATA COLLECTION Design drawings were provided for the following structures: Floating Stage Design/Shop drawings by Coquina Engineering and Construction, Inc. dated No details of the anchorage system were included. East and West Boardwalks Design drawings by Herbert Halbeck, dated The construction of the boardwalks matched the design drawings only in general section. The existing lengths were longer than those shown in the plans. EXISTING CONDITIONS AND OBSERVATIONS The facilities are located in Crane s Roost Lake, in Altamonte Springs, Fl. The lake is manmade. The inspections were performed from July 22, 2013 to July 24, The weather was generally partly cloudy or stormy with temperatures ranging from 85 to 91 degrees F. Afternoon scattered storms were present each day. Water temperature was approximately 80 degrees F. Underwater visibility

23 was typically less than 2 ft. A three-person dive team utilizing surface-supplied air, live underwater video and led by a Certified Bridge Inspector was used. The maximum depth was 16 ft. The channel bottom (lake bed) typically consisted of sand and mud, with penetrations ranging from 0.5 ft to 1.0 ft. Light algae growth was present from the waterline to the channel bottom on all structures. Floating Stage All connection hardware and components were found to be intact and functioning. All pipe truss flange interface connections were found to be secure, with no gaps or deflections. The bolts and mounting hardware showed signs of corrosion scale of approximately 1/16 to 1/4 in., but negligible section loss. The carbon steel support truss had signs of random areas of light corrosion with no pitting. The coating was found to be intact and sound except for areas adjacent to the anchoring cables. These areas had mechanical damage due to contact/chaffing from the anchor cables. These areas were approximately 12 in. wide by 8 in. long with an average penetration (wearing of metal surface) of 1/16 to 5/32 in. All areas having adjacent dissimilar metals (aluminum and carbon steel) were found to be sound with no indications of section loss due to galvanic corrosion. All tension structure tie points showed no signs of deflection or mechanical stress. The anchoring system was found to be in need of repair and received only a cursory inspection, because it is planned to be re-evaluated and/or redesigned at a later date. East Boardwalk The bents for the East Boardwalk were numbered from the south to the north, and the piles were labeled left and right looking up-station. The timber piles were found to have no signs of decay, biological damage, or mechanical damage. Only minor surface abrasion was observed. The channel bottom (lake bed) was found to have no local or general scour or any significant debris. West Boardwalk The condition of the West Boardwalk piles was the same as the East Boardwalk piles, except for the NE pile at Observation Deck No. 3. This pile had a thru-check, 4 in. long by ½ in. wide located 12 in. below the waterline. The adjacent area was probed with an awl, and sounded, and revealed no signs of decay or other damage. Overlook The observation deck piles were found to be functioning as designed with no signs of decay, biological damage, or mechanical damage. The channel bottom (lake bed) was found to have no local or general scour or any significant debris. Amphitheater and West Seawalls The precast concrete panels were found to be sound with no observed defects, except for general light scaling of less than 1/16 inch deep. The carbon steel brackets that support these panels of the pedestrian walkway were found to be intact and free of defects. The steel sheetpiling located behind the precast panels was exposed along the deeper portions of the seawall up to 4 ft. The sheetpiling was sound and free of defects where exposed. No evidence of subgrade loss was found.

24 EVALUATION AND RECOMMENDATIONS The Floating Stage was in good condition. The chaffed areas and the connection bolts were in good condition, but should be recoated in the near future to prevent a reduction in their service life. The anchoring system is recommended for repair or replacement. That redesign should include prevention of further chaffing of adjacent surfaces. The East and West Boardwalk piles were in good condition below the water line and do not require any maintenance or repair at this time. The Overlook piles were in good condition below the water line and do not require any maintenance or repair at this time. The concrete sheet piles of the Amphitheater and West Seawalls were in good condition, with only minor scaling, and require no maintenance or repair at this time. It is recommended that the Cranes Roost structures be inspected every five years. In general all of the structures only had minor deterioration or damage. There were no observations of advanced deterioration of the metal or timber members or components. Assuming that the recommended maintenance items in this report are performed, the anchoring system is redesigned and replaced, and future maintenance is performed, the structures should have a minimum service life of 20 years. Respectfully Submitted, UNDERWATER ENGINEERING SERVICES, INC. Jeffrey H. O Connor, P.E. Vice President Originated by: Marty Lee Faulk, C.B.I. #317 Lead Inspector

25 ATTACHMENT D Photo Contact Sheet

26