A mechanism protecting vehicle occupants from floor oscillation during under-vehicle explosions comprises vehicle cab sidewalls, a cab floor, cab mounts having elastomeric bodies between the cab and vehicle frame members, a shield below the cab floor, first elastomeric isolators between the shield and frame, and second elastomeric isolators between the shield and sidewalls. The second isolators collapse by an amount equal to the combined collapse of the first isolators and cab mounts. Explosive loads to the shield follow paths to different floor zones, decreasing floor oscillation. A vehicle payload area is mounted to the frame separately from the cab. The payload area and cab move independently on the frame. The payload area mounts are stiffer and smaller than the cab mounts, so explosions under the vehicle tend to accelerate the payload area before the cab.