February 2010 Final Design Report PIN 1805.81 APPENDIX G (Public Involvement (PI) Plan and Input from Stakeholders including Public) February 2010 Final Design Report PIN 1805.81 PAC Meetings Summary of Meeting #5 Lake Champlain Bridge Project Public Advisory Committee (PAC) November 13, 2009 – 1 p.m. Best Western, Ticonderoga, NY The primary purpose of this Public Advisory Committee (PAC) meeting was to discuss the condition of the Lake Champlain Bridge that led to the decision to demolish it and the resulting revised project process. Also on the agenda was a review of temporary crossing options and schedule and the communication plan for keeping the public informed. Ted Zoli, chief bridge engineer for HNTB (NYSDOT’s consultant), gave a presentation (https://www.nysdot.gov/regional-offices/region1/projects/lake-champlain- bridge/repository/LCB_PAC5_11-13-09.pdf) and fielded questions from PAC members about condition of the existing bridge that led to the recommendation to close the bridge and further investigation that led to the decision to demolish the bridge. Ted began his presentation by setting the historical context of the bridge, both as an engineering example of early continuous truss structure and as regional icon. He also noted several unusual aspects of how the bridge was constructed. Its concrete piers are non-reinforced with steel, slender in relation to the size of the superstructure and have no armor to protect against ice abrasion. Additionally, iron-ore tailings from local mines were used in forming the concrete piers, and the caissons (the underwater structure on which the piers rest) were built by a drop-bottom bucket method, rather than by tremie pipe. Ted reviewed past repair work done on the bridge, noting that repair of the piers occurred as early as 1945, indicating early design issues. This type of repair would not be expected on a bridge only fifteen years after it was built. Ted Zoli gave a detailed description of the deterioration observed by divers in the fall 2009 examination of the piers and an assessment of the bridge bearings that led to the closing of the bridge. The bearings are frozen and, with the weakened conditions of the piers, the bridge is in danger of abrupt collapse. Ted said failure would be explosive and could come without warning. Ted Zoli noted the engineers were puzzled by the rapid rate of pier deterioration since the 2005 underwater inspection. He believes the effect of Lake Champlain ice thrust into the piers and high wind loads may not have been sufficiently taken into account when the bridge was designed must be considered as contributing factors to the bridge’s decline. [It was noted by some PAC members that there may have been an earthquake during the period since 2005, which they speculated could have contributed to the deterioration]. Given the poor condition of the piers, short term rehabilitation of the bridge was dismissed as a viable option. Long term rehabilitation was also dismissed as it would require both pier and foundation replacement as well as extensive rehabilitation of the superstructure. Ted Zoli said that rehabilitation was dismissed for the following reasons: 1) the instability of working on the existing structure would put construction personnel at great risk, 2) there is more likelihood of unknowns when rehabilitating an existing 1 structure vs. replacement, and 3) the most optimistic service life of a rehabilitated bridge would be 50 years vs. 75 years of a new bridge. PAC members asked Ted Zoli numerous questions. The questions are noted in italics, below. So you think rehabilitation doesn’t make sense? No. The caissons that provide the foundation for the piers are very deep underwater and cannot be repaired. Repairs to the superstructure, connector floor beams and deck would also be significant. It’s hard to manage costs and schedule on a rehabilitation project and we are concerned about the danger of potential failure while work is being done on the bridge. How long will demolition take and can’t the bridge be replaced in less than 24 months? Demolition and design of the new bridge can happen concurrently. We estimate it will take six months to get through the design process and 18 months to build the bridge. We can begin work on the foundation before the design is finalized but we will be working around seasonal restrictions. My concern is the timeline. We will lose this coming season. We can’t afford to lose 2011 as well. It’s possible to have financial incentives for contractors to accelerate delivery of their work. This was done in Minneapolis. They built the bridge in 11 months but at three times the normal cost. Does the type of bridge that is selected add time to the schedule? No. Bridge type just adds to the cost. Historic research suggests there was steel reinforcement of the bridge. Reinforcement only occurred at the bearings. Steel bars and braces were also used as part of the coffer dam during construction but are not reinforcing the piers. The bridge closing is taking a real toll on commuters. If the bridge were rehabbed for a long term solution, is some vehicle use possible? Not entirely. Some connections of truss need to be replaced and traffic lanes would be needed so traffic impacts on a long-term rehabilitation project would be significant. The bridge would have to been taken apart in pieces. The challenges in this approach are: 1) seasonal restrictions, 2) you don’t know how bad conditions are, especially for the bridge’s underpinnings, until you get into the work, and 3) when the work is completed it will be hard to get a modern level of safety. Fifty years of service life is good as we can imagine. We would be working on a very fragile structure that would be difficult to stabilize. Perhaps most importantly, we think there would be too much risk for the contractors. We appreciate the thoroughness of the engineering report. I always thought the piers would need to be replaced. 2 The pier stems are what are seen from above but it’s the caissons deep in the lake that need to be strong and large enough to carry the loads. They should be three to four times what is visible above the lake’s surface. We also will need to plan for the impact of ice thrusts in designing the new bridge. Help me to understand how this condition was not predictable from earlier inspections. The federal process for inspecting bridges began in the 1960s and focuses on things that have failed before. The Lake Champlain Bridge is unusual in design. The piers started off on the skinny side. If masonry had been used rather than unreinforced concrete it would have been twice as strong. Rehabilitation of concrete over the years masked the problems. Also, there is a problem in this country of not making investment in bridges at the right time. Many of our bridges are 60-80 years old. It is clear that something happened between the last underwater inspection in 2005 and the recent 2009 underwater inspection. I’d like to be able to explain the situation to my constituents. Would you say that the bridge now has pneumonia because we didn’t take care of it when it had a fever? No. I think a better way to explain it is that the bridge has a very compromised immune system and the pneumonia may kill it. I don’t understand why this summer’s bridge repair started at the top and not at the bottom? After the 1-35 bridge collapse in Minneapolis from one small flaw in one place, we are now climbing all over trusses to ensure that does not happen again. Diving inspections happen every five years and perhaps federal laws should be changed. But despite the inspections happening regularly, something very dramatic happened to piers 5 and 7 between 2005 and 2009. Isn’t it all possible that putting all the weight on the bridge at the same time during this summer’s repair work caused the problem? No. The live load of traffic accounts for only a small proportion of the weight load. The biggest load is the truss. We know in the I-35 Bridge that frozen bearings and pier movement were a problem. Can you honestly say that there was a good inspection done in 2005? Yes, based on what I saw in the reports. There was consistency; nothing appeared to be missed. The same cracks noted in 2005 are the same as today. I believe something happened. The ice factor did not seem unusual but I am curious about winds as they seem to have been a little worse in the last 5-6 years. There could have been a combination of factors – temperature, wind and ice. Even today’s codes do not provide guidance for ice in lakes. Ruth Fitzgerald of Fitzgerald & Halliday, Inc. explained to the PAC how the project status has changed as a result of the bridge closing. With the determination that the existing bridge cannot be rehabilitated and the strong feedback at public meetings that the Lake Champlain crossing remain in the current location, the environmental process is 3 expected to be greatly curtailed. While there will still be many processes that must be followed, it’s likely a “Documented Categorical Exclusion” will be pursued rather than an Environmental Impact Statement. Ruth said there will be two separate environmental processes – one for demolition of the existing bridge and one for new bridge design/construction that will be following concurrently.