OPTIMUM DESIGN METHODOLOGY FOR ELEVATED TRANSIT STRUCTURES. EXECUTIVE SUMMARY
Methodologies are investigated for designing high efficiency, elevated, urban guideways. The most efficient spans are continuous where the pier supports, bending stiffness and unit mass are optimally distributed. Calculations lead to spans of least overall weight, balanced peak stresses under all loading, and minimum rms vertical deflection for the vehicle trajectories. The study is in four parts. In Chapter 1, optimal pier spacings for uniform spans are predicted, where span inertia effects are included. Calculated optimal span responses to constant loads at constant speed, verified experimentally, show a peak stress reduction of up to 30 percent, compared to simple spans end-to-end. In Chapter 2, similar results are found for uniform, continuous, inertialess, spans where the transit mass is much larger than the span mass. In Chapter 3, the effects on span efficiency of the nonuniform stiffness and unit mass parameters are investigated, where extensive use is made of computer graphics to illustrate the design methodology. In Chapter Four, the Duke University transit system is the reference case used for alternative design studies, where up to 40 percent reductions in concrete weight are possible. These methodologies can be successively employed to minimize urban guideway costs through weight reduction. The optimal spans are slim, aesthetic structures, affording high degrees of passenger ride comfort.
- See also Final Report, PB82-126996.
Duke UniversityDepartment of Civil Engineering
Durham, NC United States 27706
Urban Mass Transportation Administration400 7th Street, SW
Washington, DC United States 20590
- Wilson, J F
- Publication Date: 1981-10
- Pagination: 12 p.
- TRT Terms: Alternatives analysis; Bending moments; Computer graphics; Computer programming; Dynamic loads; Dynamic structural analysis; Elevated guideways; Methodology; Structural design
- Uncontrolled Terms: Dynamic response; Forced vibration
- Subject Areas: Construction; Operations and Traffic Management; Public Transportation; I70: Traffic and Transport;
- Accession Number: 00346705
- Record Type: Publication
- Source Agency: National Technical Information Service
- Report/Paper Numbers: UMTA-NC-11-0010-81-1Summary
- Files: NTIS, TRIS, USDOT
- Created Date: Jan 29 1982 12:00AM