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Page 1 of 59 <br />City of Everett Merrill & Ring Bridge Replacement <br />Exhibit A <br />SCOPE OF WORK <br />Background: <br />This project will replace the existing City of Everett’s (City) Merrill & Ring Bridge (SID <br />08560600) in Mukilteo Boulevard corridor with a new multi-span bridge. <br />The Merrill & Ring (M&R) Bridge was built in 1931 and was widened in 1980. The bridge <br />serves as a vital link in a chain of three bridges that provide the only access to neighborhoods <br />located along Mukilteo Boulevard, an NHS route between the cities of Everett and Mukilteo. The <br />other two bridge are Maple Heights (SID 08560500) and Edgewater (SID 08559300). Both <br />bridges received funding from Local Bridge Program to eliminate their deficiencies. The Maple <br />Heights Bridge deficiencies have recently been eliminated through a seismic upgrade and the <br />Edgewater Bridge deficiencies are being eliminated through a full replacement that is currently <br />under construction. <br />Mukilteo Boulevard traverses deep ravines and winds along steep hillsides and is the only access <br />to the neighborhoods along its length. It also serves over 6000 vehicles per day in its load <br />restricted condition. If any two of these three bridge were to fail during a seismic event there is <br />no other access to the areas isolated by the bridge failures. <br />The M&R Bridge is a steel deck truss that has been widened by adding two additional matching <br />deck trusses, one on each side of the original deck truss girders, to support the wider deck and <br />sidewalks. These new trusses have provided additional load paths for structural redundancy. <br />Significant effort and money have been expended in keeping the structure in service, but <br />widespread steel deterioration caused by a leaking deck have made a replacement project <br />necessary. <br />The engineering analyses has revealed that the bridge has less capacity than previously thought <br />due to widespread corrosion deterioration in critical locations of floor beam splices. The load <br />rating report shows that it is deficient for all analyzed loading and the current Sufficiency Rating <br />is 21.68 SD. <br />Furthermore, the bridge was also evaluated for seismic vulnerability and the analysis shows that <br />the bridge is deficient in shear and flexural capacities on its interior columns and has deficient <br />interior truss diagonal members. These deficiencies may cause a superstructure and/or <br />substructure failure during a large seismic event.