TTI Research Supervisor:
Nauman M. Sheikh, P.E.
Associate Research Engineer
Texas A&M Transportation Institute
College Station, Texas 77843-3135
(979) 317-2694 [email protected]
Pooled Fund Technical Representative:
Jeffery K. Petterson, P.E.
Roadside Safety Engineer
Washington State Department of Transportation
P.O. Box 47329
Olympia, Washington 98504-7246
(360) 705-7278 [email protected]
States with extreme winter weather are faced with difficulty in maintaining and repairing W-beam guardrail and end terminal posts installed in soil. Due to frozen soil conditions, posts installed directly in soil require more resources and equipment to repair and can delay repair of a damaged guardrail and/or end terminal. In addition, longer duration needed for repair increases the exposure of maintenance workers to oncoming traffic. Some states currently install the steel posts in steel tubes as an alternative to posts installed directly into soil to facilitate repair. This project evaluates the performance of the W-beam guardrail and end terminals with steel posts installed in buried steel sleeves. The researchers performed surrogate bogie vehicle impact tests on posts installed directly in soil and compared their performance to posts installed in buried steel sleeves. On finding similar force-deflection response, the researchers performed a full-scale crash test with posts installed in sleeves. Test 3-35 of American Association of State Highway and Transportation Officials (AASHTO) Manual for Assessing Safety Hardware (MASH) was performed with the non-proprietary Downstream Anchor Terminal (DAT) anchoring each end of the test installation.
The 31-inch W-beam guardrail with DAT and steel posts installed in steel sleeves performed acceptably for MASH Test 3-35. Results of the test show that W-beam guardrail steel posts installed in buried steel tubes perform similar to the direct embedded posts in guardrail’s end terminal region and the length of need.