and a corrugation depth of at least four inches the plate has thicknesses of up to 1 2 inch and more also disclosed are structures such as tunnel type heavy load supporting structures defined by upright and horizontal structure portions which extend over no more than about 180 u00b0 while being capable of supporting up to 40 feet of ground fill and payload thereon the corrugated plate can be used singly or as double spaced apart plate assemblies which are hollow or filled with concrete or a like material including steel reinforcing bars for the concrete the corrugated plate can also be formed into vertical sectional retaining walls bin type retaining walls bridge abuttment walls flat support surfaces such as bridge decking open air structures guard rails sheet piling etc application_number US 90038378 A description referring first to fig1 a corrugated plate 2 constructed in accordance with the present invention has a plurality of generally sinusoidal parallel longitudinally extending corrugations 4 which defines alternating convex peaks 6 and concave troughs 8 the corrugations have a pitch that is adjacent peaks and adjacent troughs have a spacing parallel to the sheet of at least about twelve inches and the corrugations have a depth that is a peak and an adjacent trough have a spacing transverse to the sheet of at least about four inches the concave and convex peaks and troughs have a curvature radius r of at least about two inches and preferably of about two and one quarter inches the thickness of the plate.