6 resultados para Comparison between methods of analysis
em Iowa Publications Online (IPO) - State Library, State of Iowa (Iowa), United States
Resumo:
The need for upgrading a large number of understrength and obsolete bridges in the United States has been well documented in the literature. Through the performance of several Iowa DOT projects, the concept of strengthening bridges (simple and continuous spans) by post-tensioning has been developed. The purpose of this project was to investigate two additional strengthening alternatives that may be more efficient than post-tensioning in certain situations. The research program for each strengthening scheme included a literature review, laboratory testing of the strengthening scheme, and a finite-element analysis of the scheme. For clarity the two strengthening schemes are presented separately. In Part 1 of this report, the strengthening of existing steel stringers in composite steel beam concrete-deck bridges by providing partial end restraint was shown to be feasible. Part 2 of this report summarizes the research that was undertaken to strengthen the negative moment regions of continuous, composite bridges. Two schemes were investigated: post-compression of stringers and superimposed trusses within the stringers.
Resumo:
The overall objective of this experimental program was to obtain quantitative comparisons between leaded and nonleaded gasolines as used in a variety of Iowa State Highway Connnission vehicles. These quantitative comparisons were to be made in terms of exhaust emissions, maintenance costs and fuel economy.
Resumo:
This Agreement made and entered i into this 1 1st day of July 2009, at Des Moines, Iowa, pursuant to the provisions of Chapter 20 of the Iowa Code, by and between the State of Iowa (hereinafter referred to as the Employer) and UE Local 893/Iowa United Professionals, and its appropriate affiliated locals, as representatives of employees employed by the State of Iowa, as set forth specifically in Appendix A (hereinafter referred to as the Union).
Resumo:
This Agreement made and entered i into this 1 1st day of July 2009, at Des Moines, Iowa, pursuant to the provisions of Chapter 20 of the Iowa Code, by and between the State of Iowa (hereinafter referred to as the Employer) and UE Local 893/Iowa United Professionals, and its appropriate affiliated locals, as representatives of employees employed by the State of Iowa.
Resumo:
This Agreement made and entered into this 1st day of July 2009 at Des Moines, Iowa, pursuant to the provisions of Chapter 20 of the Iowa Code, by and between the State of Iowa (hereinafter referred to as the Employer) and the State Police Officers Council, and its appropriate affiliated sub-organizations (hereinafter referred to as the Council), as representatives of employees employed by the State of Iowa.
Resumo:
Since the beginning of channel straightening at the turn of the century, the streams of western Iowa have degraded 1.5 to 5 times their original depth. This vertical degradation is often accompanied by increases in channel widths of 2 to 4 times the original widths. The deepening and widening of these streams has jeopardized the structural safety of many bridges by undercutting footings or pile caps, exposing considerable length of piling, and removing soil beneath and adjacent to abutments. Various types of flume and drop structures have been introduced in an effort to partially or totally stabilize these channels, protecting or replacing bridge structures. Although there has always been a need for economical grade stabilization structures to stop stream channel degradation and protect highway bridges and culverts, the problem is especially critical at the present time due to rapidly increasing construction costs and decreasing revenues. Benefits derived from stabilization extend beyond the transportation sector to the agricultural sector, and increased public interest and attention is needed.