A system (10) for sieving ballast comprises a first sieve (26) and a second sieve (28) which is located behind the first sieve (26) in a first direction (100). A discharge collection conveyor (32.1) is located directly under a first discarded ballast outlet (42) of the first sieve (26) in order to collect a flow of discarded ballast which comes from the first sieve (26) and to convey it in a second direction (200) counter to the first direction (100). A rerouting collection conveyor directly collects the flow being discharged from a clean ballast outlet of the second sieve in order to convey it in the first direction (100). The rerouting collection conveyor extends under the first sieve (26) at a lower height than the discharge collection conveyor.

A system (10) for sieving ballast comprises a first sieve (26) and a second sieve (28) which is located behind the first sieve (26) in a first direction (100). A discharge collection conveyor (32.1) is located directly under a first discarded ballast outlet (42) of the first sieve (26) in order to collect a flow of discarded ballast which comes from the first sieve (26) and to convey it in a second direction (200) counter to the first direction (100). A rerouting collection conveyor directly collects the flow being discharged from a clean ballast outlet of the second sieve in order to convey it in the first direction (100). The rerouting collection conveyor extends under the first sieve (26) at a lower height than the discharge collection conveyor.

The invention is a system and method for repairing, improving, and stabilizing subgrade and subsoil/natural ground layers of a rail bed generally consisting of softer soils. One embodiment includes a method of installing subsurface inclusions and ballast fills comprising injected slurry mixtures of stabilizing material such as cement grout mixed with in situ soil. Another embodiment includes a system of installed ground inclusions and ballast fills. Another embodiment includes an integrated system of equipment for emplacing the system of inclusions and ballast fills.

A track maintenance machine for stabilizing a ballast bed of a track after a tamping operation, includes a machine frame mobile on on-track undercarriages and a stabilizing unit which has rollers for gripping a track grid and a vibration generator for actuating the track grid with a vibration. A clearing device is disposed at both longitudinal sides of the track maintenance machine in front of the stabilizing unit with regard to a working direction. Each respective clearing device includes a clearing tool which can be lowered into the ballast bed to remove ballast from a respective sleeper-end region. Thus, preconditions are created by using the stabilizing unit to achieve an increased lowering of the track grid as compared to a normal stabilizing procedure. A method for operating a track maintenance machine is also provided.

The invention is a system and method for repairing, improving, and stabilizing subgrade and subsoil/natural ground layers of a rail bed generally consisting of softer soils. One embodiment includes a method of installing subsurface inclusions and ballast fills comprising injected slurry mixtures of stabilizing material such as cement grout mixed with in situ soil. Another embodiment includes a system of installed ground inclusions and ballast fills. Another embodiment includes an integrated system of equipment for emplacing the system of inclusions and ballast fills.