At about 11:30 p.m., on Jan. 16, 2009, 18 freight cars carrying molten sulfur derailed south of Littleton, Colo., causing damage to an existing mechanically stabilized earth (MSE) retaining wall that was supporting the light rail service adjacent to the freight rail system. The freight tracks share a corridor with the Regional Transportation District (RTD) light rail system, and the severe damage to the MSE wall and supporting light rail lines caused an immediate suspension of light rail service, which forced local commuters to seek alternate means of transportation. More than 100 personnel, including Burlington Northern/Santa Fe (BNSF) and RTD officials, fire and rescue, and local police were involved in surveying the damage and establishing a clean-up plan.

In the early hours of Jan. 17, the Denver Transit Construction Group (DTCG) contacted The Reinforced Earth Company (RECo) to participate in the evaluation of the existing MSE retaining wall and recommend the most expeditious repair to minimize service disruption of the light rail lines. RECo’s project manager, Ben Palm, was on-site at the derailment and began immediate coordination with DTCG officials to determine a course of action. DTCG (a joint venture between Herzog Contracting, St. Joseph, Mo., and Stacey & Witbeck Inc., Alameda, Calif.) is currently under contract to construct the new West Corridor Light Rail line for the RTD in nearby Golden, Colo., in which RECo is supplying more than 245,000 square feet of retaining walls.

With RECo under contract for the RTD project, a timely resolution was easily achieved to remove the 400-plus feet of damaged MSE wall in its entirety, and reconstruct utilizing the RECo design and materials.

RECo’s project manager and engineers worked in close coordination to establish the limits and design parameters to be utilized in a redesign of the damaged structure, and engineering drawings were completed and approved by DTCG and RTD by Jan. 20. Replacement precast facing panels, soil reinforcements, and accessories were obtained from the West Corridor project inventory and precast coping was obtained from an ongoing project in Missouri to eliminate fabrication and construction delays. DTCG work crews had completely deconstructed and excavated the MSE wall section by Jan. 19, and RECo’s first material deliveries were made Jan. 20, when construction of the new wall section began. The entire wall section was completed within 10 days and light rail service was restored Feb. 2. “The problem was resolved efficiently because of the availability of materials, and services were restored to the track with minimized downtime to RTD commuters,” Palm said. “The temperatures were frigid and DTCG crews worked around the clock to finish the project quickly.”

This article was contributed by The Reinforced Earth Company. For more info, visit www.reinforcedearth.com