MULTI-DIRECTIONAL SLIP BASE FOR BREAK-AWAY LUMINAIRE SUPPORTS

RESEARCH WAS CONDUCTED TO DEFINE THE HAZARD POTENTIAL OF EXISTING SUPPORTS AND TO INVESTIGATE MEANS TO ELIMINATE IT THE TRIANGULAR SLIP BASE WAS DEVELOPED WITH MULTI- DIRECTIONAL PROPERTIES, WHICH IS EASILY ADAPTABLE TO FIELD MODIFICATION FOR EXISTING LUMINAIRE SUPPORTS. THE BASE IS COMPOSED OF TWO IDENTICAL PLATES. EACH PLATE HAS SLOTS AT THE APEXES OF THE TRIANGLE. THE BOTTOM PLATE IS RIGIDLY ATTACHED TO THE FOUNDATION, WHILE THE TOP PLATE IS SECURED TO THE LUMINAIRE SUPPORT POST. SMALL BASES WERE TESTED IN THE LABORATORY TO STUDY THE EFFECTS OF BASE BOLT TENSION, SLOT ANGLE, AND ANGLE OF ATTACK ON THE BASE PERFORMANCE UNDER DYNAMICALLY APPLIED LOADS. TEST RESULTS SHOW THAT THE SLOT ANGLE IS CRITICAL TO THE PERFORMANCE OF THE BASE. TESTS INDICATE THAT THE SLOT ANGLE SHOULD BE 30 DEGREES. ANGLES MUCH LARGER THAN THIS ARE NOT PRACTICAL DUE TO THE DECREASE IN WASHER BEARING AREA. THE BASE HAD THE LEAST RESISTANCE TO APPLIED LOAD AT AN ANGLE OF INCIDENCE OF 30 DEGREES FOR ALL BOLT TENSIONS USED IN THE TESTS. THE RESISTANCE OF SLIP INCREASES WITH INCREASED BOLT TENSION. IT IS CONCLUDED THAT THE TRIANGULAR SLIP BASE IS A FEASIBLE DESIGN FOR A MULTI- DIRECTIONAL BREAK-AWAY BASE FOR LUMINAIRE SUPPORTS. THE BASE BOLTS SHOULD BE DESIGNED TO RESIST THE WIND LOAD, ASSUMING NO PRELOAD. TEST DATA INDICATE THAT THE SUPPORT POST WILL ALIGN ITSELF WITH THE PATH OF THE COLLIDING VEHICLE.

• Supplemental Notes:
  • Res Report 75-10, PP 1-29, 13 FIG, 5 TAB, 7 REF, 1 APP
• Corporate Authors:

  Texas Transportation Institute

  Texas A&M University System, 1600 E Lamar Boulevard
  Arlington, TX  United States  76011

  Texas State Department of Highways & Public Transp

  11th and Brazos Streets
  Austin, TX  United States  78701
• Authors:
  • Edwards, T C
• Publication Date: 1967-8

Subject/Index Terms

• TRT Terms: Aerodynamic force; Alignment; Bolts; Breakaway supports; Crashes; Highway safety; Luminaires; Structural plates; Tension; Wind
• Uncontrolled Terms: Plates; Slippage; Wind load
• Old TRIS Terms: Resistance
• Subject Areas: Bridges and other structures; Highways; Safety and Human Factors;

Filing Info

• Accession Number: 00208472
• Record Type: Publication
• Files: TRIS, STATEDOT
• Created Date: Jul 1 1994 12:00AM