The Geopier GeoSpike system provides high stiffness and superior levels of performance to increase the railroad track subgrade modulus and decrease permanent track settlements.

Geopier GeoSpike® System

The Geopier GeoSpike(sm) system is a patented, low-cost method for treating weak railroad track subgrades. This design-build system creates strong and elements in weak subgrade soils and can be installed without removing railroad tracks or ties. Subgrade improvement takes place by driving pre-manufactured GeoSpike shells in pairs between rail ties at regular intervals. The GeoSpike shell is driven in-place by inserting a driving mandrel within the shell and advancing the mandrel to design depths. The expanded top of the shell compresses between ties during insertion and expands back to its original shape after clearing the rail ties to allow for efficient load transfer from the rail ties to the GeoSpike system. After driving to design depths, aggregate is placed within the confining shell and compacted by repeated insertion by the driving mandrel. The dynamic loads from the passing rail cars arch through the ballast to the GeoSpike, and are effectively transferred through the shell and densely compacted aggregate down to a suitable bearing layer. Read More >>

The Geopier GeoSpike system provides high stiffness and superior levels of performance to increase the railroad track subgrade modulus and decrease permanent track settlements.

GeoSpike Installation

The patented Geopier GeoSpike(sm) installation process displaces soil during installation and utilizes vertical impact ramming energy to construct Rammed Aggregate Pier® elements that exhibit superior strength and stiffness in soft soils. 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.

The Geospike shell is placed on the specially designed tapered mandrel and is driven 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 railroad ties and expand back out once driven to the design depth. The top of the shell is driven below the ballast material so as to not impact ballast replacement and maintenance.

After driving the Geospike shell to the design depth, the confining shell remains in place. Aggregate is placed and densified inside of the shell through static downward crowd force and dynamic vertical ramming energy from the hammer and 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. The patented expanded top increases the load attraction capacity of the stiff elements to efficiently capture more of the applied dynamic stresses.

The installed 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.

Installation Methodology: The patented Geopier GeoSpike installation process displaces soil during installation and utilizes vertical impact ramming energy to construct Read More >> Rammed Aggregate Pier® elements that exhibit superior strength and stiffness in soft soils. 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.