DYNAMIC TESTS OF SHORT SECTIONS OF CORRUGATED METAL BEAM GUARDRAIL

THE RESULTS OF EIGHT FULL SCALE VEHICLE IMPACT TESTS INTO SHORT SECTIONS (LESS THAN 100 FT.) OF 27-IN. HIGH BLOCKED-OUT CORRUGATED METAL BEAM GUARDRAIL ARE REPORTED. TWO TESTS WERE PERFORMED ON FREE STANDING UNANCHORED SHORT SECTIONS, THREE TESTS ON FREE STANDING SECTIONS, USING TWO DIFFERENT END ANCHORAGE SYSTEMS AND THREE TESTS ON SIMULATED BRIDGE APPROACH GUARDRAIL FLARES USING A CABLE ANCHOR ASSEMBLY ON THE UPSTREAM OR APPROACH END AND RIGID ATTACHMENT TO THE CONCRETE BRIDGE RAIL PARAPET AT THE OTHER END. THE TESTS WERE CONDUCTED AT SPEEDS RANGING FROM 56 TO 63 MPH AND APPROACH ANGLES VARYING FROM 24 TO 33 DEGREES UTILIZING 1964 TO 1966 SEDANS WEIGHING APPROXIMATELY 4500 LBS. THE FIRST TWO TESTS (131 AND 132) PROVED THAT SHORT, FREE STANDING UNANCHORED GUARDRAIL SECTIONS UP TO 62.5 FT IN LENGTH AND INEFFECTIVE UNDER SEVERE IMPACT LOADING CONDITIONS (APPROXIMATELY 60 MPH/25 DEG). THIS IN TURN INDICATES THAT ANY UNANCHORED GUARDRAIL SECTION, REGARDLESS OF LENGTH, IS VULNERABLE WHEN STRUCK WITHIN 30 FT OF EITHER END. THE RESULTS OF TEST 133 AND 134 INDICATE THAT SHORT GUARDRAIL SECTIONS WITH SLOPING RAIL ANCHORAGE ("TEXAS TWIST) ARE STRUCTURALLY ADEQUATE WHEN STRUCK IN THE CENTER (FULL HEIGHT SECTION), BUT PERFORMANCE IS QUESTIONABLE WITH REGARD TO IMPACTS INTO THE RAMPED ENDS. AS A RESULT OF TEST 135 THROUGH 138, AN EFFECTIVE CABLE ANCHORING DEVICE FOR SHORT FREE STANDING SECTIONS OF GUARDRAIL WAS DEVELOPED. IN ADDITION, AN EFFICIENT BRIDGE APPROACH GUARDRAIL FLARE DESIGN WAS DEVELOPED WHICH PROVIDES RELATIVELY SMOOTH TRANSITION FROM THE SEMI-FLEXIBLE BLOCKED-OUT BEAM BARRIER (8- BY 8-IN. POSTS AT 6-FT 3-IN. O.C.) THROUGH A SEMI-RIGID SYSTEM (10- BY 10-IN. POSTS AT 3-FT 1-1/2-IN. O.C.) TO A RIGID REINFORCED CONCRETE BRIDGE RAIL.

  • Supplemental Notes:
    • Rept No M/r 636392, 38 PP, 29 FIG, 8 REF
  • Corporate Authors:

    California Division of Highways

    Bridge Department
    Sacramento, CA  United States  05914
  • Authors:
    • Nordlin, E F
  • Publication Date: 1968-10

Media Info

Subject/Index Terms

Filing Info

  • Accession Number: 00203433
  • Record Type: Publication
  • Source Agency: Nat Safety Council Safety Res Info Serv
  • Files: TRIS
  • Created Date: Jan 19 1970 12:00AM