Construction of a reinforced soil wall near the railroad

Construction of a reinforced soil wall near the railroad

Owner City of Wichita, KS Union Pacific Railroad Burlington Northern Sante Fe Railroad
General Contractor Dondlinger & Sons Wichita, KS
Installer Wildcat Construction Wichita
Mechanical Support StrataGrid GS200, SG350, SG500,Temporary wire form baskets
Facing 90-deg welded wire form with secondary geogrid wrap and non-woven geotextile
Structure Geometry 150,000SF, 26ft(max), 1H:9V

Project Overview

The merger of Union Pacific and Southern Pacific Railroads was applauded by citizens. However, the problem arose when the Union Pacific railroad proposed doubling the movement of mile-long coal trains through the heart of the city. A construction of the central rail corridor was suggested to alleviate traffic congestion near that area.

An amalgamation of federal, state, and local grants and private railroad financing funded this 98 million dollar endeavor. The objective was to elevate a pair of side-by-side railroad tracks along the Burlington Northern Santa Fe right-of-way through the downtown traffic corridor.

After completion, the project would provide new grade separations, connecting five new bridges and one rehabbed bridge along a 1.8-mile strip; allowing both trains and vehicles to flow unimpeded through eight major thoroughfares.

The Challenge

  1. The comprehensive plan for erecting permanent, back-to-back T wall retaining walls required a temporary reinforced wall. This temporary wall was also needed to support the combined seismic and dynamic loading of two fully loaded freight trains passing side by side.
  2. There was a need to maintain active rail service adjacent to the construction site and vehicle crossings between the bridge abutments.

Strata's Innovative Solution

The StrataSlope system using StrataGrid along with Microgrid wrap back into the wall for facing stability integrated with 100% compacted pit sand backfill easily met design specifications for supporting loads of 900 lbs. per sq.ft.(compared to 250 lb.per sq.ft.loads commonly required for highway roadway traffic).

Due to the unique design of StrataSlope, mechanical support for the heavy loading was achieved by installing horizontal layers of StrataGrid at 18’ intervals (one layer per wire basket) all the way to top of the wall, with additional structural stability provided by a facing of temporary wire baskets. These were backfilled with pit sand and wrapped in a blanket of Microgrid face wrap.

The site was monitored for several months even after completion. The movement in the track bed was measured using eight monitoring pins. The extensive surveillance validated the fact that even with a heavy load, the structure never moved more than half-inch in any direction, including vertical settlement.

Strata's Value Addition

  • Robust and cost-effective solution compared to conventional methods
  • Environment-friendly solution that leaves very low carbon footprint owing to minimal resources requirements
  • Increased lifespan with lower maintenance