SMALL CRATER BRIDGING MATERIAL

AIR FORCE RAPID RUNWAY REPAIR (RRR) PROCEDURES MUST ADDRESS SMALL BOMB CRATERS FROM 6 TO 10 FT IN DIAMETER WITH LITTLE UPHEAVE. EXISTING TECHNIQUES REQUIRE CRATER-FILLING, WHICH IS LABOR, MATERIAL AND EQUIPMENT INTENSIVE. THIS PROPOSAL PRESENTS DESIGN CONCEPTS FOR CRATER-COVERS WHICH WILL NOT REQUIRE THE CRATER TO BE FILLED. UNSUPPORTED CRATER COVERS HAVE TWO BASIC REQUIREMENTS: STRENGTH SO THAT THEY DO NOT BREAK, AND STIFFNESS SO THAT THEY DO NOT BEND (DEFLECT) EXCESSIVELY. A PRELIMINARY CONCEPT IS SHOWN WHICH CONSISTS OF A THICKENED SECTION UNDER THE COVER (USING SOME OF THE SPACE INSIDE THE CRATER) AND ADJUSTABLE CABLE SUPPORTS WHICH WILL ENABLE A SINGLE DESIGN TO SUPPORT THE MAXIMUM LOADS FOR ANY SIZE CRATER IN THE 6 TO 10 FT RANGE. PHASE I WILL CONSIST OF 3 MAJOR TASKS: DEVELOPMENT OF PRECISE DESIGN REQUIREMENTS, STRUCTURAL ANALYSIS AND FINAL DESIGN, AND PREPARATION OF PHASE II PLANS FOR CONSTRUCTION AND TESTING.