70th Street

Replacing old water mains, reconstructing combined sewers, and adding additional capacity to alleviate flooding, improve overall drainage, and improve the quality of drinking water in the Maspeth section of Queens, New York. The project as designed includes open-cut installation of 5-foot by 8-foot box culverts and microtunnel to install 3,425 feet of 96-inch inside diameter/115.5-inch outside diameter RCP in seven drives. The microtunneling was performed from 30-foot diameter liner plate shafts to depths of 65 feet using sodium silicate permeation grouting at the portals to provide face stability during launch and recovery. The longest drive was 1,600 feet.

A notable value engineering achievement of the project was the microtunneled installation of 230 feet of 85-inch Hobas pipe in lieu of the contract specified open-cut installation of 5 foot x 8 foot box culvert across Queens Boulevard that required multiple lane closures during nighttime hours. This substitution eliminated the night work while allowing seven of the eight lanes of traffic to remain open during construction, thereby greatly benefitting the local community and the traveling public.

Visit the Trenchless Technology article to read about our 70th Street underground utility and trenchless construction project in more depth.