Abstract: 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.