The patented GeoSpike system installation is similar to other Geopier Rammed Aggregate Pier solutions where direct vertical ramming energy compacts high-quality aggregate to form high stiffness elements that provide superior support capacity, increased bearing pressure and settlement control. The Geopier GeoSpike solutions are designed to reinforce weak rail subgrade soils to increase the track subgrade modulus and reduce deflections that occur under dynamic loading conditions.
Geopier licensed crews place the GeoSpike on the specially designed tapered mandrel and drive the shell into the ground using a strong static force augmented by high-frequency vertical ramming energy. The patented shape of the GeoSpike shell is designed to squeeze between closely spaced track sleepers and expand back out once driven to the design depth. To prevent damage to the shell during routine ballast maintenance, the top of the shell is embedded below the sleepers to depths of 12-18in.
After driving to the design depth, the confining shell remains in place and is backfilled with small diameter aggregate placed in lifts and compacted with the driving mandrel. The process creates dense, high stiffness elements that offer superior strength and performance by transferring dynamic loads from passing rail cars through the poor subgrade down to a suitable bearing layer.
Once installed, the GeoSPoke elements significantly improve the subgrade modulus to effectively decrease the cyclic deflections of the track from passing wheel loads and reduce the permanent settlement of the track over its lifetime.
Using GeoSpike allows for a quick, intermediate solution that will eliminate the need for over-excavation-based subgrade repair and has the ability to safely strengthen railway subgrades while minimising downtime to rail operations.
Rail owners, contractors, and designers use Geopier's GeoSpike to improve the railway track subgrade modulus and decrease permanent track settlements.