The ornamental design for a loadingdockramp, as shown and described.
FIG. 1 is a perspective view of a loading dock ramp;
FIG. 2 is a side view of the loading dock ramp of FIG. 1;
FIG. 3 is a side view of the loading dock ramp of FIG. 1; and,
FIG. 4 is a top plan view of the loading dock ramp of FIG. 1.
The broken lines shown in the figures are for the purpose of illustrating portions and form no part of the claimed design. The truck, the ground and the small vehicle shown in the broken lines are for the purpose of illustrating environment structure which form no part of the claimed design.