AWARD OF EXCELLENCE: Longevity Category

Washburn Tunnel Leaksealing

Waller, Texas

Submitted by De Neef Construction Chemicals, Inc.

In 1987 a repair contractor repaired the Washburn Tunnel that runs beneath the Houston Ship Channel. Forty leaks in the landmark facility were stopped with a polyurethane chemical grout material.

The tunnel’s design and construction were so durable that the repairs performed by the contractor were the first major rehabilitation work performed on the tunnel since it opened nearly fifty years ago.

The material specified for the task is a water-activated urethane gel. This grout material activates on contact with water and is formulated to retain its flexibility. A twin piston pump is used to inject the twin streams of grout and water into the cracks. The contractor’s contract also called for repairs to expansion joints in the masonry retaining wall at each portal and repairs to slab cracks within pump and ventilation buildings.

The grouting contractor completed its scope of the work within 29 of the allotted 30 days. The overall results were excellent in terms of time, performance and expectations. Records in 1987 suggest that the 800+ gallons of grout is the largest quantity of the urethane material ever applied in the south central region in a job of this scope. An inspection in 1998 confirmed no leakage in the tunnel through the injected cracks.