Bridge engineers of the Texas State Department of Highways and Public Transportation (SDHPT) have long desired a low service level bridge rail for use on culverts and low bridges. It was desired that such a rail would be economical and compatible in strength and stiffness with the standard Texas Guard Fence (12 ga. W-beam, mounted on 7 in. diameter timber or W6 x 8.5 steel post at 6 ft-3 in. spacing). Present bridge rails designed according to AASHTO Standard Specifications for Highway Bridges (12th edition) are expensive, very stiff and rigid, and require special transitions to join them with the standard flexible guardrail on each end. The Tubular W-Beam bridge rail presented here does not meet the elastic analysis and allowable stress design requirements of AASHTO, but it does meet full-scale vehicle crash test and performance requirements of such bridge rails and, consequently, is exempt from the allowable stress design requirements. The Tubular W-Beam bridge rail consists of standard guardrail posts W6 x 8.5 spaced 1.9 m (6ft-3in.) with a breakaway welded connection. The breakaway feature is achieved by completely welding up the tension flange and only slightly welding the inside of the compression flange and providing no weld on the web.
Tubular W-Beam Bridge Rail
1978
58 pages
Report
No indication
English
Double-beam bridge crane capable of preventing rail gnawing
European Patent Office | 2022
|Engineering Index Backfile | 1941
|