2012 Trenchless Storm Drainage Repairs

Owner: City of Bellevue Utilities Department

Client: Vanaja Rajah, P.E., Project Manager

Four segments of approximately 630 feet of failing 30-inch corrugated metal pipe storm drain were located between two streets along a steep slope (approximately 29%) with no vehicular access to intermediate structures in the Somerset neighborhood in the City of Bellevue. The project was located adjacent to high voltage overhead power lines and next to an Olympic Pipeline high pressure gas main in an easement. The City had originally intended to line only specific segments. However, CHS evaluated several different alternatives and recommended lining the entire length of storm drain with  cured-in-place pipe (CIPP) to eliminate the need to construct a road to allow vehicular access to intermediate structures. Eliminating the vehicular access requirement removed the need for a critical areas ordinance evaluation, saving the City time and money for permitting. Following City acceptance of the recommendation, CHS prepared plans, specifications, contract documents and a construction cost estimate to line the entire length of storm drain with cured-in-place pipe. The CIPP lining was installed within a period of one week. The construction method only required pavement disruption around the upstream storm drain structure. By avoiding the need to disrupt pavement at the downstream structure, the project was completed under the contract amount. The short construction window and limited pavement disturbance minimized the inconvenience to property owners in this high profile area in the City of Bellevue.

Dates:
Pre-design 2011, Design 2012, Construction 2012
CHS Staff:
Scott Christensen, P.E., Principal-in-Charge
Darrel Frame, P.E., Project Manager
Craig Christensen, P.E., Design Engineer

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