Norfolk Southern - Wentzville, MO

Norfolk Southern (NS) was looking for an alternative option to solve subgrade issues that are prevalent around the rail yard. An onsite inspection was performed focusing on a 350 ft section of track having a history of surface defects and repeated maintenance. The site inspection revealed soft, wet subgrade conditions below the ballast that were indicated by mud pumping and soil bulging at the toe of the ballast line. Geotechnical investigation provided evidence of adequate bearing soils 8 feet below the ballast line.

The Geopier solution for this project consisted of 6 ft GeoSpike® elements installed so that the GeoSpike apexes were 1-1.5 ft below the existing ties. The GeoSpike elements were installed in pairs spaced every other tie to resist a Cooper E-80 derived working load of 16 kips per GeoSpike. Approximately 200 GeoSpike® elements were installed in the 350’ section in about 3 days using a rubber tire excavator with vibratory driver.

Geopier was able to work in-between trains and clear the track for traffic. The project was completed in conjunction with the switching operations with minimal impact on service.

The geotechnical challenges with this project related to the soft, wet subgrade underlying the ballast. NS had attempted to address the issue several times by grouting and excavating and replacing the ballast, however the problems persisted.

The Geopier®  solution for this project consisted of 6 ft GeoSpike® elements installed so that the GeoSpike apexes were 1-1.5 ft below the existing ties. The GeoSpike elements were installed in pairs spaced every other tie to resist a Cooper E-80 derived working load of 16 kips per GeoSpike. Approximately 200 GeoSpike® elements were installed in the 350’ section in about 3 days using a rubber tire excavator with vibratory driver.

Geopier was able to work in-between trains and clear the track for traffic. The project was completed in conjunction with the switching operations with minimal impact on service.