Railroad Subgrade Soil Stabilization Lift, and Re-alignment

A 70 foot section of railroad track near Green River, Wyoming had experienced ongoing settlement issues. During springtime, and high water events, the area required weekly re-compaction and leveling. The replaced ballast would continually sink into the wet subgrade soils.

A factor that contributed to the problem, is that the area is located at a drainage point of the surrounding hillsides.

Settlement of the subgrade soils was a continual problem for the railroad as well as the unsafe conditions for freight trains and their personnel travelling over this section of track.

Keeping the track open and safe was a major concern for the Rail Company.

CST partnered with Watco Rail representative Neal Ward to design an effective repair solution for the settled areas of track.

An initial site survey was conducted on all areas of the settled rail. Areas for treatment were identified and a site specific injection design was created to lift the settled areas, and stabilize the subgrade soils beneath the track and ballast to mitigate against any future settlement.

CST installed a high density structural polymer at pre-determined depths to treat weak soil and lift the settled track sections. Crews alternated between sections to allow train traffic to continue through the area.

All sections of settled track and weak soil zones were stabilized.

Injections made into the weak soil zones effectively pushed water away from the areas, and provided a protective barrier beneath the ballast, to stabilize and protect the area against future settlement.

Railroad track was lifted, and realigned to provide a stable, safe passage of the company’s freight trains and personnel traveling across the tracks.

All work was completed in a matter of 3 working shifts without major closure or disruption to trains traveling through.

Dry Fork Mine Rail – Gillette, WY

Load Out & Rail Void Fill & Stabilization

CST Deep Injection Technologies were employed to fill voids and stabilize the floor in the Train load-out building and along rails in the loading area of the Dry Fork Mine in Gillette Wyoming.

Floor stabilization, void fill, and sub-grade stabilization of the building and adjacent track area were completed in three shifts by Concrete Stabilization Technologies, Inc., providing the customer with a permanent solution for their production site.

Cereal Plant Rail Car Soil Stabilization – Ogden, UT

The Problem

Undermining and settlement of sub grade soils of railway track and load out canopy area of Cereal Food Processors, Inc. plant, Ogden Utah.

Situation

Concrete Stabilization Technologies, Inc. Field Consultant, Jonathon George was contacted by Scott Roberts of Cereal Foods, Inc. concerning settlement issues around the load out area for rail cars at the cereal processing plant located in Ogden, UT.

Settlement occurred due to a water main leak which had undermined sub grade soils around approximately 120 linear feet of railway track. The area of rail canopy is supported by five pillars. The middle of the five pillars showed the greatest amount of settlement of 1 to ½ inches while the other pillars in both directions had also experienced settlement, but to a lesser degree.

Facts for Consideration

The settled area of the Cereal Food Processor plant is in area used to load rail cars with grain. The area is used on a daily basis with empty rail cars rolling into the canopy area, being loaded with grain, and then moving the heavy load to other areas of the plant for production. This being a vital part of the plant’s production sequence, taking the tracks out of service for an extended period of time, would not only slow production, but affect the plant’s profit margin. Due to the non-invasive process and rapid curing time of CST geopolymers, the track was only out of service for a couple of hours.

Soil test results revealed compromised soil in the settled areas at a depth of three to four feet below the surface grade. No settlement of the tracks themselves had occurred, however, tests performed beneath the tracks did reveal soft soils. As a preventative measure against future settlement in the track area, it was recommended to the owner to treat soils beneath the rail ballast as well.

Solution

Initial soil tests were made in the areas of the canopy pillars and track sub grade. Results of the testing indicated very soft soil three to four feet down into the sub grade area. Penetrometer testing also revealed soft soil beneath the track area as well.

CST’s deep injection method was used to stabilize the affected areas. Repair work began at the center of the east track. 5/8” holes were drilled and probes placed into the sub grade soils. Geopolymer was injected through the probes into the soil on five feet center and four feet below the top of the concrete/asphalt overlay. The purpose of the injections between the tracks was to fill any voids, stabilizing the weak soil, and interlocking the sub grade with the ballast, preventing future settlement.

Once the track area was completed, injections were then made beneath the spread footer of each of the five pillars to stabilize soil and prevent settlement. The two pillars with the most severe settlement were addressed first. Injections were made at depths of one, three, and five feet below the bottom of each spread footer. For the remaining three pillars, injection was made at one and three feet below the bottom of each spread footer. Close monitoring of surface movement at the surface was made during injection, and movement was detected from all injections.

Results

  • 120 Linear Feet of track area sub grade soils successfully stabilized
  • CST successfully stabilized the five supporting canopy pillars in the rail car load out area
  • CST successfully stabilized 120 linear feet of weak soil beneath the rail track area.

Benefits

Time Savings:  Repairs were completed in one day. Track was useable immediately following injection of sub grade soils.
Cost Savings:  Conservatively reduced repair costs by 50% (versus reconstruction).
Longevity:  Repairs permanently stabilized the source of the settlement – weak soils, mitigating future settlement and damage to canopy as well as rail track line through area.