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Engineers/Consultants <br />Attention: Quinn Golden, P.E. <br />Company: Granite Construction Inc. <br />From: Joe Schrank, P.E. and Frank Pita, P.E., L.E.G. <br />Job No: 4070.8 <br />Date: December 23, 2008 <br />Subject: Evaluation of Water Main Loading <br />Everett Station <br />Everett, Washington <br />Hi Quinn, <br />Per your request, Jacobs Associates (JA) ;-erformed a preliminary evaluation of <br />the loading on the existing water main at Everett Station due to the crane pick of <br />a pedestrian bridge. There is an existing 48-inch diameter water main that was <br />constructed in 1930 and owned by the City of Everett in the project area, and the <br />crane is likely to be above the water main during the crane pick. <br />We understand that the City of Everett is requiring a geotechnical evaluation of <br />the loading on the water main during the crane pick. The purpose of our work <br />was to: <br />1. Estimate the loading on the water main during the crane pick; <br />2. Identify the allowable pressure on the water main due to the crane pick; <br />and <br />3. Recommend precautions that should be taken to protect the water main <br />and allow the crane to set-up over it. <br />Background Information <br />Based on information provided by you in emails and conversations with us <br />between Tuesday, December 16 and Friday, December 19, we understand that <br />the pedestrian bridge will be picked up with a Grove GMK 7550 rubber -tired <br />crane. You provided the expected outrigger loading of the crane during the pick, <br />the crane dimensions, and a plan map showing the water main and the <br />approximate location of the crane. You reported that the minimum depth to the <br />concrete casing above the water mein was 5.9 feet below the existing ground <br />surface, and the concrete casing was .;ix feet wide. <br />We also understand that: <br />o 1 he City of Everett has stated that HS 20 live loading is allowable over the <br />water main, and a higher loading may be acceptable if our analysis shows <br />that the water main can safely bear the additional load. <br />1109 First Avenue, Suite 501 Seattle, WA 98101-2963 Phone: (206) 588-8200 Fax: (206) 588-8201 <br />