MWW LinNwood Water TunneL Inspection

 
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In 2014, Kapur & Associates partnered with a national tunnel firm to act as the local presence on the Linwood Tunnel Investigation and Rehabilitation.  This project, over 7,100 LF in length, was to address deficiencies in the tunnel, vents, and structures at both ends.  Our role was to investigate, report, prepare plans, and assist in survey to repair the Gate and Vent areas of the Linwood Tunnel.

This tunnel, originally completed in 1920, connects the Riverside pumping station to the Linwood Water Facility, about 1.33 miles apart, and 80 to 120 feet below grade.  Tasks included removing more than 3.5 mil gallons of water from the tunnel, ventilate, and light the length of the tunnel for survey and inspection in a 36-hour window. 

Kapur survey staff provided horizontal and vertical control, alignments, scanning, and sectioning to insure tunnel integrity (roundness), while our inspectors evaluated 15 gates at both tunnel ends, and ventilation areas along the stretch of the 9’ high tunnel. 

Although the gates and tunnel integrity were in adequate condition, the longitudinal cracking in the tunnel required more than 7,500 LF of specialized grout port repair, which was performed in winter to reduce dewatering efforts and hasten repairs.  All work was completed in the planned 90-day window.