7 resultados para POSITIONED FLAP
em Iowa Publications Online (IPO) - State Library, State of Iowa (Iowa), United States
Resumo:
The Iowa Department of Transportation (DOT), working closely with the Federal Aviation Administration (FAA), strives to ensure that Iowa’s system of public airports is positioned to meet the needs of businesses, residents, and visitors to our state. Airports must be accessible and positioned to safely meet different levels of aviation activity. In partnership with the FAA and various cities, counties, and airport authorities, the Iowa DOT helps to direct the systematic development of public airports. This report is a summary of a more comprehensive technical report that outlines a strategic plan for improving the performance of airports in Iowa over the next 20 years. More information on the technical report and on individual reports prepared for each of the public airports can be obtained from the Iowa DOT, Office of Aviation website at www.iawings.com. The Iowa Aviation System Plan provides the Iowa DOT with an important tool to monitor the ability of airports to meet customer needs. The plan also provides a means to measure the effects of investment on the performance of the Iowa Aviation System. Over the next 20 years, federal, state, local, and private funding will be needed to ensure that the aviation system meets goals established in this study. It is estimated that at least $821 million will be needed over the next 20 years if airports in Iowa are to respond to objectives set by the system plan. In future years, the plan will enable the Iowa DOT to measure system performance. By tracking key indicators for the airport system, it will be possible for the Iowa DOT and the FAA to formulate strategies for responding to Iowa’s air transportation needs. The Iowa Aviation System Plan provides a guide for the state and its communities to ensure that the vision established for the Iowa Aviation System can be achieved.
Resumo:
The Iowa Department of Transportation (DOT), working closely with the Federal Aviation Administration (FAA), strives to ensure that Iowa’s system of public airports is positioned to meet the needs of businesses, residents, and visitors to our state. Airports must be accessible and positioned to safely meet different levels of aviation activity. In partnership with the FAA and various cities, counties, and airport authorities, the Iowa DOT helps to direct the systematic development of public airports. This report is a summary of a more comprehensive technical report that outlines a strategic plan for improving the performance of airports in Iowa over the next 20 years. More information on the technical report and on individual reports prepared for each of the public airports can be obtained from the Iowa DOT, Office of Aviation website at www.iawings.com. The Iowa Aviation System Plan provides the Iowa DOT with an important tool to monitor the ability of airports to meet customer needs. The plan also provides a means to measure the effects of investment on the performance of the Iowa Aviation System. Over the next 20 years, federal, state, local, and private funding will be needed to ensure that the aviation system meets goals established in this study. It is estimated that at least $821 million will be needed over the next 20 years if airports in Iowa are to respond to objectives set by the system plan. In future years, the plan will enable the Iowa DOT to measure system performance. By tracking key indicators for the airport system, it will be possible for the Iowa DOT and the FAA to formulate strategies for responding to Iowa’s air transportation needs. The Iowa Aviation System Plan provides a guide for the state and its communities to ensure that the vision established for the Iowa Aviation System can be achieved.
Resumo:
The Iowa Department of Transportation (DOT), working closely with the Federal Aviation Administration (FAA), strives to ensure that Iowa’s system of public airports is positioned to meet the needs of businesses, residents, and visitors to our state. Airports must be accessible and positioned to safely meet different levels of aviation activity. In partnership with the FAA and various cities, counties, and airport authorities, the Iowa DOT helps to direct the systematic development of public airports. This report is a summary of a more comprehensive technical report that outlines a strategic plan for improving the performance of airports in Iowa over the next 20 years. More information on the technical report and on individual reports prepared for each of the public airports can be obtained from the Iowa DOT, Office of Aviation website at www.iawings.com. The Iowa Aviation System Plan provides the Iowa DOT with an important tool to monitor the ability of airports to meet customer needs. The plan also provides a means to measure the effects of investment on the performance of the Iowa Aviation System. Over the next 20 years, federal, state, local, and private funding will be needed to ensure that the aviation system meets goals established in this study. It is estimated that at least $821 million will be needed over the next 20 years if airports in Iowa are to respond to objectives set by the system plan. In future years, the plan will enable the Iowa DOT to measure system performance. By tracking key indicators for the airport system, it will be possible for the Iowa DOT and the FAA to formulate strategies for responding to Iowa’s air transportation needs. The Iowa Aviation System Plan provides a guide for the state and its communities to ensure that the vision established for the Iowa Aviation System can be achieved.
Resumo:
The Iowa Transportation Improvement Program (Program) is published to inform Iowans of planned investments in our state’s transportation system. The Iowa Transportation Commission (Commission) and Iowa Department of Transportation (Iowa DOT) are committed to programming those investments in a fiscally responsible manner. This document serves as the Iowa DOT's annual report as required by Iowa Code section 7A.9. This document reflects Iowa’s multimodal transportation system by the inclusion of investments in aviation, transit, railroads, trails, and highways. A major component of this program is the highway section that documents programmed investments on the primary highway system for the next five years. A large part of funding available for highway programming comes from the federal government. Accurately estimating future funding levels of this federal funding is dependent on having a current enacted multi-year federal transportation authorization. The most recent authorization, Safe, Accountable, Flexible, Efficient Transportation Equity Act: A Legacy for Users (SAFETEA-LU), expired September 30, 2009, and to date it has been extended five times because a new authorization has not yet been enacted. The current extension expires December 31, 2010. While Iowa law does not require the adoption of a Program when federal transportation funding is being reauthorized, the Commission believes it is important to adopt a Program in order to continue on-going planning and project development efforts and to be well positioned when a new authorization is adopted. However, it is important to recognize that, absent a federal authorization bill, there is significant uncertainty in the forecast of federal revenues. The Commission and the Iowa DOT will continue to monitor federal revenues and will adjust future investments as needed to maintain a fiscally responsible Program. In developing the highway section of the program, the Commission’s primary investment objective remains stewardship (i.e. safety, maintenance and preservation) of Iowa’s existing highway system. In fact, over $1.2 billion is programmed in FY2011 through FY2015 for preservation of Iowa’s existing highway system and for enhanced highway safety features. The highway section also includes significant investments for interstate modernization on I-29 inSioux City, on I-29/80/480 in Council Bluffs, and on I-74 in Bettendorf/ Davenport. Another highway programming objective reflected in this Program is maintaining the scheduled completion of capacity and economic development projects that were identified in the previous Program. Finally, with the limited remaining funds the Commission has furthered the investment in capacity and economic development by adding a few projects to the Program. The Iowa DOT and Commission appreciate the public’s involvement in the state’s transportation planning process. Comments received personally, by letter or through participation in the Commission’s regular meetings or public input meetings held around the state each year, are invaluable in providing guidance for the future of Iowa’s transportation system.
Resumo:
The Iowa Transportation Improvement Program (Program) is published to inform Iowans of planned investments in our state’s transportation system. The Iowa Transportation Commission (Commission) and Iowa Department of Transportation (Iowa DOT) are committed to programming those investments in a fiscally responsible manner. This document reflects Iowa’s multimodal transportation system by the inclusion of investments in aviation, transit, railroads, trails, and highways. A major component of this program is the highway section that documents programmed investments on the primary highway system for the next five years. A large part of funding available for highway programming comes from the federal government. Accurately estimating future federal funding levels is dependent on having a current enacted multi-year federal transportation authorization. The most recent authorization, Safe, Accountable, Flexible, Efficient Transportation Equity Act: A Legacy for Users (SAFETEA-LU), expired September 30, 2009, and to date it has been extended seven times because a new authorization has not yet been enacted. The current extension will expire September 30, 2011. This leads to significant uncertainty in federal funding; however, it is becoming evident that, in Federal Fiscal Year 2012 and beyond, federal funding revenue will likely be reduced by 25 percent from current levels in order to match revenue that flows into the Highway Trust Fund. This Program reflects this anticipated reduction in federal funding. While Iowa law does not require the adoption of a Program when federal transportation funding is being reauthorized, the Commission believes it is important to adopt a Program in order to continue on-going planning and project development efforts so that Iowa will be well positioned when a new authorization is adopted. However, it is important to recognize that, absent a federal authorization bill, there is significant uncertainty in the forecast of federal revenues. The Commission and the Iowa DOT will continue to monitor federal revenues and will adjust future investments as needed to maintain a fiscally responsible Program. For 2012-2016, approximately $2.3 billion is forecast to be available for highway right of way and construction. In developing the highway section of the Program, the Commission’s primary investment objective remains stewardship (i.e. safety, maintenance and preservation) of Iowa’s existing highway system. Over $1.3 billion is programmed in FY2012 through FY2016 for preservation of Iowa’s existing highway system and for enhanced highway safety features. The highway section also includes significant interstate investments on I-29 in Sioux City, I-29/80/480 in Council Bluffs, and I-74 in Bettendorf/Davenport. The FY2016 programming for construction on I-74 in Bettendorf/Davenport is the first of several years of significant investments that will be monitored for available funding. Approximately $200 million of the investments on these three major urban interstate projects address preservation needs. In total, approximately $1.5 billion is programmed for highway preservation activities for 2012- 2016. Another highway programming objective is maintaining the scheduled completion of capacity and economic development projects. Projects that were previously scheduled to be completed within the previous Program continue on their current schedule. However, due to the reduction of projected federal revenues, the Commission has delayed by one year the initiation of construction of all multi-year non-Interstate capacity and economic development projects that cannot be completed within this Program. These projects are U.S. 20 in Woodbury County, U.S. 30 in Benton County, U.S. 61 in Louisa County, and Iowa 100 in Linn County. The Iowa DOT and Commission appreciate the public’s involvement in the state’s transportation planning process. Comments received personally, by letter or through participation in the Commission’s regular meetings or public input meetings held around the state each year, are invaluable in providing guidance for the future of Iowa’s transportation system. It should be noted that this document is a planning guide. It does not represent a binding commitment or obligation of the Commission or Iowa DOT, and is subject to change.
Resumo:
Precast prestressed concrete panels have been used as subdecks in bridge construction in Iowa and other states. To investigate the performance of these types of composite slabs at locations adjacent to abutment and pier diaphragms in skewed bridges, a research prcject which involved surveys of design agencies and precast producers, field inspections of existing bridges, analytical studies, and experimental testing was conducted. The survey results from the design agencies and panel producers showed that standardization of precast panel construction would be desirable, that additional inspections at the precast plant and at the bridge site would be beneficial, and that some form of economical study should be undertaken to determine actual cost savings associated with composite slab construction. Three bridges in Hardin County, Iowa were inspected to observe general geometric relationships, construction details, and to note the visual condition of the bridges. Hairline cracks beneath several of the prestressing strands in many of the precast panels were observed, and a slight discoloration of the concrete was seen beneath most of the strands. Also, some rust staining was visible at isolated locations on several panels. Based on the findings of these inspections, future inspections are recommended to monitor the condition of these and other bridges constructed with precast panel subdecks. Five full-scale composite slab specimens were constructed in the Structural Engineering Laboratory at Iowa State University. One specimen modeled bridge deck conditions which are not adjacent to abutment or pier diaphragms, and the other four specimens represented the geometric conditions which occur for skewed diaphragms of 0, 15, 30, and 40 degrees. The specimens were subjected to wheel loads of service and factored level magnitudes at many locations on the slab surface and to concentrated loads which produced failure of the composite slab. The measured slab deflections and bending strains at both service and factored load levels compared reasonably well with the results predicted by simplified Finite element analyses of the specimens. To analytically evaluate the nominal strength for a composite slab specimen, yield-line and punching shear theories were applied. Yield-line limit loads were computed using the crack patterns generated during an ultimate strength test. In most cases, these analyses indicated that the failure mode was not flexural. Since the punching shear limit loads in most instances were close to the failure loads, and since the failure surfaces immediately adjacent to the wheel load footprint appeared to be a truncated prism shape, the probable failure mode for all of the specimens was punching shear. The development lengths for the prestressing strands in the rectangular and trapezoidal shaped panels was qualitatively investigated by monitoring strand slippage at the ends of selected prestressing strands. The initial strand transfer length was established experimentally by monitoring concrete strains during strand detensioning, and this length was verified analytically by a finite element analysis. Even though the computed strand embedment lengths in the panels were not sufficient to fully develop the ultimate strand stress, sufficient stab strength existed. Composite behavior for the slab specimens was evaluated by monitoring slippage between a panel and the topping slab and by computation of the difference in the flexural strains between the top of the precast panel and the underside of the topping slab at various locations. Prior to the failure of a composite slab specimen, a localized loss of composite behavior was detected. The static load strength performance of the composite slab specimens significantly exceeded the design load requirements. Even with skew angles of up to 40 degrees, the nominal strength of the slabs did not appear to be affected when the ultimate strength test load was positioned on the portion of each slab containing the trapezoidal-shaped panel. At service and factored level loads, the joint between precast panels did not appear to influence the load distribution along the length of the specimens. Based on the static load strength of the composite slab specimens, the continued use of precast panels as subdecks in bridge deck construction is recommended.
Resumo:
Recent reports indicate that of the over 25,000 bridges in Iowa, slightly over 7,000 (29%) are either structurally deficient or functionally obsolete. While many of these bridges may be strengthened or rehabilitated, some simply need to be replaced. Before implementing one of these options, one should consider performing a diagnostic load test on the structure to more accurately assess its load carrying capacity. Frequently, diagnostic load tests reveal strength and serviceability characteristics that exceed the predicted codified parameters. Usually, codified parameters are very conservative in predicting lateral load distribution characteristics and the influence of other structural attributes. As a result, the predicted rating factors are typically conservative. In cases where theoretical calculations show a structural deficiency, it may be very beneficial to apply a "tool" that utilizes a more accurate theoretical model which incorporates field-test data. At a minimum, this approach results in more accurate load ratings and many times results in increased rating factors. Bridge Diagnostics, Inc. (BDI) developed hardware and software that are specially designed for performing bridge ratings based on data obtained from physical testing. To evaluate the BDI system, the research team performed diagnostic load tests on seven "typical" bridge structures: three steel-girder bridges with concrete decks, two concrete slab bridges, and two steel-girder bridges with timber decks. In addition, a steel-girder bridge with a concrete deck previously tested and modeled by BDI was investigated for model verification purposes. The tests were performed by attaching strain transducers on the bridges at critical locations to measure strains resulting from truck loading positioned at various locations on the bridge. The field test results were used to develop and validate analytical rating models. Based on the experimental and analytical results, it was determined that bridge tests could be conducted relatively easy, that accurate models could be generated with the BDI software, and that the load ratings, in general, were greater than the ratings, obtained using the codified LFD Method (according to AASHTO Standard Specifications for Highway Bridges).