Rigid Inclusions (RI)

Rigid inclusions are essentially deep foundation elements that transfer loads through a weak or soft stratum into a lower load bearing stratum.  They are unreinforced columns of stone, concrete or grout that are installed through a steel casing with a specialized drill bit.  They are considered ground improvement because they are not connected to what they are supporting.  Typically a platform of consisting of stone and geogrid is placed on top of the rigid inclusions prior to construction of a shallow foundation.  The thickness of the platform is correlated with the horizontal spacing of the rigid inclusions.