This alter performs a grounding “separation check.” This is similar to the standard GROUNDCHECK, but compares the grounding force on each DOF to the stiffness at that DOF. Execution of the grounding check is performed at each level during the reduction and is controlled by the GROUNDCHECK Case Control. If the ratio of any grounding force to the corresponding stiffness diagonal is greater than the threshold (default = 1.E-8) the values are output in a format similar to the grounding forces.