Broken Arrow City Council
Meeting of: 07-18-2017
To: Mayor and City Council
From: Department of Engineering and Construction
Title:
title
Approval of and authorization to execute an Agreement for Professional Consultant Services with Olsson Associates, Inc., for Design of a Tiger Hill Soldier Pile Retaining Wall
End
Background:
Following the partial collapse of the Flight Safety retaining wall on the east side of Tiger Hill at Kenosha Street (71st Street South) and 9th Street (Lynn Lane) in May 2015, Engineering and Construction (E&C) Department contracted with Olsson Associates, Inc., to conduct a geotechnical investigation of the wall that the City constructed on the north side. Olsson's report was submitted August 6, 2015. The report contained general recommendations for remedial action to prevent failure of the City wall. The E&C Department requested Olsson to submit a proposal for development of remedial plans for repair or replacement of the wall. Those plans were submitted in October 2016 and recommended a support wall being built in front of the existing wall to provide the necessary structural support. On January 19, 2019, the City Council approved construction of a wall in front of the existing wall.
Since those plans were submitted, the City has been negotiating an economic development agreement for the property in front of the wall at the corner of Kenosha Street and 9th Street. Part of the development will be to lower the site approximately 4 to 5 feet, which would further compromise the Tiger Hill Wall and compromise the constructability of the new support wall. The E & C Department has now asked Olsson for a fee proposal to develop site plans to drop the entire developable site by 4 to 5 feet and to design a Modified Soldier Pile Wall, allowing for better constructability and allowing the site to be lower. A modified soldier pile wall is a support wall that is placed...
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