46 research outputs found
Upgrading Safety Performance in Retrofitting Traffic Railing Systems
DOT-FH-11-8100From bridge rail information of 51 State highway agencies and personal interviews with five selected highway agencies, current state-of-the-art of bridge railing safety performance was assessed. Based on the analysis of 14 specific railing designs, an estimated assessment of the performance of bridge rails on a national scale is presented. The data indicates that a significant percentage of existing railings may be below currently attainable safety performance standards. Bridge railing designs are grouped into four categories according to profile geometry and features that are amenable to a common retrofit design. Two categories, II and III, represent about 82 percent of existing installations. Five retrofit designs for Categories II and III were developed and evaluated by a 22-crash test program. Although not crash-test evaluated, an improved approach guardrail design features a thrie beam rail element and a breakaway cable terminal
Retrofit Railings for Narrow Through Truss and Other Obsolete Bridge Structures
DOT-FH-11-9418Through truss structures are unique in that the superstructure of the bridge is exposed to impacts from errant vehicles. Effective bridge railings must not only exclude these vehicles from contacting the critical truss members by limiting system deflection, but must also prevent heavy vehicles from rolling over the barrier and contacting a truss member. Complete collapse of truss structures has resulted from automobile impacts as well as heavy vehicle impacts. Two bridge railing retrofit systems were systematically designed and developed in this project. The high performance system is designed to contain and limit vehicle roll of 20,000-lb (9000-kg) buses impacting at 55 mph (90 kmph) and a 15-deg angle. The low service retrofit system contains and redirects a 4500-lb (2000-kg) car impacting at 60 mph (95 kmph) and a 15-deg angle without endangering the truss members behind the retrofit system. Crash tests with vehicles ranging from the bus to an 1800-lb (800-kg) minicompact vehicle were used in the development and evaluation. Design drawings of the bridge rails, bridge attachment detail and approach rail are included in the report
Guardrail-Bridge Rail Transition Designs, Volume I: Research Report
DTFH61-83-C-00028This project was concerned with the transition designs used between w-beam and the guardrail, and rigid bridge rail parapets or wingwalls. State designs submitted to the federal highway administration (FHWA) were rated and designs selected for crash test evaluation. New designs were also formulated and subjected to crash test evaluation. Most of the crash tests were conducted with 4500 lb (2000 kg) cars at 60 mph (95 km/h) and a 25 degree angle. Design drawings are presented along with recommendations for use of these transition designs. Guidelines for transition features are given and design procedures for independent end blocks are given
Muscular and functional effects of partitioning exercising muscle mass in patients with chronic obstructive pulmonary disease - a study protocol for a randomized controlled trial
Analysis of cellular and humoral immune responses against cytomegalovirus in patients with autoimmune Addison’s disease
Upgrading safety performance in retrofitting traffic railing systems. Final report.
Federal Highway Administration, Washington, D.C.Mode of access: Internet.Author corporate affiliation: Southwest Research Institute, San Antonio, Tex.Report covers the period 1 July 1973-1 June 1976Subject code: CDGCSubject code: CDISubject code: WOB*CDSubject code: WVIFLSubject code: YC
Guardrail testing program III: final report.
Federal Highway Administration, Eastern Federal Lands Highway Division, Sterling, Va.Mode of access: Internet.Author corporate affiliation: Southwest Research Institute, San Antonio, Tex.Subject code: BEDSubject code: BEESubject code: BWSubject code: CDGCSubject code: CDHSubject code: CDHCSubject code: CDISubject code: CDSSubject code: KLESubject code: WVIF
Test and evaluation of eccentric loader BCT guardrail terminals. Volume 2 - Appendix. Final Report.
Federal Highway Administration, Washington, D.C.Mode of access: Internet.Author corporate affiliation: Southwest Research Institute, San Antonio, Tex.Report covers the period Sept 1983 - Sept 1985Subject code: CDIKSubject code: DECDSubject code: DECDHSubject code: WVIF
Test and evaluation of eccentric loader BCT guardrail terminals. Volume 1. Final report.
Federal Highway Administration, Washington, D.C.Mode of access: Internet.Author corporate affiliation: Southwest Research Institute, San Antonio, Tex.Report covers the period Sept 1983 - Sept 1985Subject code: CDIKSubject code: WVIF