885 resultados para Projects in dispute
Resumo:
To provide insight into subgrade non-uniformity and its effects on pavement performance, this study investigated the influence of non-uniform subgrade support on pavement responses (stress and deflection) that affect pavement performance. Several reconstructed PCC pavement projects in Iowa were studied to document and evaluate the influence of subgrade/subbase non-uniformity on pavement performance. In situ field tests were performed at 12 sites to determine the subgrade/subbase engineering properties and develop a database of engineering parameter values for statistical and numerical analysis. Results of stiffness, moisture and density, strength, and soil classification were used to determine the spatial variability of a given property. Natural subgrade soils, fly ash-stabilized subgrade, reclaimed hydrated fly ash subbase, and granular subbase were studied. The influence of the spatial variability of subgrade/subbase on pavement performance was then evaluated by modeling the elastic properties of the pavement and subgrade using the ISLAB2000 finite element analysis program. A major conclusion from this study is that non-uniform subgrade/subbase stiffness increases localized deflections and causes principal stress concentrations in the pavement, which can lead to fatigue cracking and other types of pavement distresses. Field data show that hydrated fly ash, self-cementing fly ash-stabilized subgrade, and granular subbases exhibit lower variability than natural subgrade soils. Pavement life should be increased through the use of more uniform subgrade support. Subgrade/subbase construction in the future should consider uniformity as a key to long-term pavement performance.
Resumo:
This report describes results from a study evaluating the use of stringless paving using a combination of global positioning and laser technologies. CMI and Geologic Computer Systems developed this technology and successfully implemented it on construction earthmoving and grading projects. Concrete paving is a new area for considering this technology. Fred Carlson Co. agreed to test the stringless paving technology on two challenging concrete paving projects located in Washington County, Iowa. The evaluation was conducted on two paving projects in Washington County, Iowa, during the summer of 2003. The research team from Iowa State University monitored the guidance and elevation conformance to the original design. They employed a combination of physical depth checks, surface location and elevation surveys, concrete yield checks, and physical survey of the control stakes and string line elevations. A final check on profile of the pavement surface was accomplished by the use of the Iowa Department of Transportation Light Weight Surface Analyzer (LISA). Due to the speed of paving and the rapid changes in terrain, the laser technology was abandoned for this project. Total control of the guidance and elevation controls on the slip-form paver were moved from string line to global positioning systems (GPS). The evaluation was a success, and the results indicate that GPS control is feasible and approaching the desired goals of guidance and profile control with the use of three dimensional design models. Further enhancements are needed in the physical features of the slipform paver oil system controls and in the computer program for controlling elevation.
Resumo:
The discrepancies between the designed and measured camber of precast pretensioned concrete beams (PPCBs) observed by the Iowa DOT have created challenges in the field during bridge construction, causing construction delays and additional costs. This study was undertaken to systematically identify the potential sources of discrepancies between the designed and measured camber from release to time of erection and improve the accuracy of camber estimations in order to minimize the associated problems in the field. To successfully accomplish the project objectives, engineering properties, including creep and shrinkage, of three normal concrete and four high-performance concrete mix designs were characterized. In parallel, another task focused on identifying the instantaneous camber and the variables affecting the instantaneous camber and evaluated the corresponding impact of this factor using more than 100 PPCBs. Using a combination of finite element analyses and the time-step method, the long-term camber was estimated for 66 PPCBs, with due consideration given to creep and shrinkage of concrete, changes in support location and prestress force, and the thermal effects. Utilizing the outcomes of the project, suitable long-term camber multipliers were developed that account for the time-dependent behavior, including the thermal effects. It is shown that by using the recommended practice for the camber measurements together with the proposed multipliers, the accuracy of camber prediction will be greatly improved. Consequently, it is expected that future bridge projects in Iowa can minimize construction challenges resulting from large discrepancies between the designed and actual camber of PPCBs during construction.
Resumo:
Durante el siglo XIX se ejecutan en Catalunya proyectos de grandes regadíos en las tierras con mejores aptitudes para ello, como son las de la Depresión Central leridana, las del delta del Ebro o las del Bajo Llobregat. La excepción será la llanura del Ampurdán, concretamente, su mitad norte. No obstante, la profusión de intentos es elevada, aunque ninguno dará resultados prácticos hasta los años 60 del siglo XX. Esto ha reforzado su desconocimiento y, mediante el artículo, se quiere paliar este déficit. En primer lugar, se repasan algunos de los viajeros y eruditos que, entre los siglos XVII y XIX, facilitaron datos sobre los riegos existentes y algunas propuestas para mejorarlos. A continuación se analizarán los tres intentos más significativos para ampliarlos durante la segunda mitad del XIX. Se abordarán sus objetivos, sus peculiaridades, sus promotores, los discursos que los justificaron y los motivos de su fracaso
Resumo:
This report highlights the Fiscal Year 2014 accomplishments of IOWAccess, including IOWAccess projects in development. Certain services offered through IOWAccess charge a value-added fee. Contained within this report are a description of the IOWAccess business model and the processes employed by IOWAccess to fund and monitor projects, along with a listing of projects funded during the reporting period.
Resumo:
US Geological Survey (USGS) based elevation data are the most commonly used data source for highway hydraulic analysis; however, due to the vertical accuracy of USGS-based elevation data, USGS data may be too “coarse” to adequately describe surface profiles of watershed areas or drainage patterns. Additionally hydraulic design requires delineation of much smaller drainage areas (watersheds) than other hydrologic applications, such as environmental, ecological, and water resource management. This research study investigated whether higher resolution LIDAR based surface models would provide better delineation of watersheds and drainage patterns as compared to surface models created from standard USGS-based elevation data. Differences in runoff values were the metric used to compare the data sets. The two data sets were compared for a pilot study area along the Iowa 1 corridor between Iowa City and Mount Vernon. Given the limited breadth of the analysis corridor, areas of particular emphasis were the location of drainage area boundaries and flow patterns parallel to and intersecting the road cross section. Traditional highway hydrology does not appear to be significantly impacted, or benefited, by the increased terrain detail that LIDAR provided for the study area. In fact, hydrologic outputs, such as streams and watersheds, may be too sensitive to the increased horizontal resolution and/or errors in the data set. However, a true comparison of LIDAR and USGS-based data sets of equal size and encompassing entire drainage areas could not be performed in this study. Differences may also result in areas with much steeper slopes or significant changes in terrain. LIDAR may provide possibly valuable detail in areas of modified terrain, such as roads. Better representations of channel and terrain detail in the vicinity of the roadway may be useful in modeling problem drainage areas and evaluating structural surety during and after significant storm events. Furthermore, LIDAR may be used to verify the intended/expected drainage patterns at newly constructed highways. LIDAR will likely provide the greatest benefit for highway projects in flood plains and areas with relatively flat terrain where slight changes in terrain may have a significant impact on drainage patterns.
Resumo:
Efforts to improve safety and traffic flow through merge areas on high volume/high speed roadways have included early merge and late merge concepts and several studies of the effectiveness of these concepts, many using Intelligent Transportation Systems for implementation. The Iowa Department of Transportation (Iowa DOT) planned to employ a system of dynamic message signs (DMS) to enhance standard temporary traffic control for lane closures and traffic merges at two bridge construction projects in western Iowa (Adair County and Cass County counties) on I-80 during the 2008 construction season. To evaluate the DMS system’s effectiveness for impacting driver merging actions, the Iowa DOT contracted with Iowa State University’s Center for Transportation Research and Education to perform the evaluation and make recommendations for future use of this system based on the results. Data were collected over four weekends, beginning August 1–4 and ending October 16–20, 2008. Two weekends yielded sufficient data for evaluation, one of transition traffic flow and the other with a period of congestion. For both of these periods, a statistical review of collected data did not indicate a significant impact on driver merging actions when the DMS messaging was activated as compared to free flow conditions with no messaging. Collection of relevant project data proved to be problematic for several reasons. In addition to personnel safety issues associated with the placement and retrieval of counting devices on a high speed roadway, unsatisfactory equipment performance and insufficient congestion to activate the DMS messaging hampered efforts. A review of the data that was collected revealed different results taken by the tube counters compared to the older model plate counters. Although variations were not significant from a practical standpoint, a statistical evaluation showed that the data, including volumes, speeds, and classifications from the two sources were not comparable at a 95% level of confidence. Comparison of data from the Iowa DOT’s automated traffic recorders (ATRs) in the area also suggested variations in results from these data collection systems. Additional comparison studies were recommended.
Resumo:
Initiated in 2001, the West Tarkio Creek Watershed Project has a proven track record of implementing an enormous amount of structural conservation practices. To date, over $925,000 has been spent to build 69 miles of terraces on 63 cooperators' land. The success of the Project was due in large part to the conservation ethic of the landowners to improve their farms, preserve the productivity of the land, and protect West Tarkio Creek. This has been made possible through funding from DSC Watershed Protection Funds (WSPF) which has provided $1,362,592 in cost share funds since 2001 but is has been severely limited in recent years due to shortages within the State’s budget. The original project goals called for the construction of 750,000 feet (142 miles) of terraces to effectively treat the watershed. In order to meet these goals and bring the project to a successful endpoint, another 153,000 feet (29 miles) remain to be constructed by the landowners with the help of the SWCD staff. Severe rain events in recent years have caused an enormous amount of damage throughout the region, these storms were helpful in identifying where watershed work remains to be completed. Scars on the landscape in the aftermath of the storms clearly etched out the specific location where additional practices are needed in addition to those proposed in the original project work plan. Project supporters are confident that the WIRB Program can unlock this potential and pave the way for what can become known as one of the most effective land treatment projects in Iowa.
Resumo:
The City of Remsen is proactively addressing an increase of nitrates in their public water supply before it becomes a financial catastrophe for them. An intensive assessment was conducted by the Iowa DNR Source Water Protection program as one of four pilot projects in the state. This assessment far surpassed standard desktop assessments and gathered monitoring information in-the-field led by a local watershed group. This was incorporated into a computer modeling program to help the local watershed group discuss alternatives. This comprehensive approach clearly identified the source of nitrate infiltration as a cropland area adjacent to the City well field. Many options were evaluated but only one option provided an economical, viable and secure answer to the water supply needs of Remsen for generations to come. The watershed planning group chose to seek the purchase of this critical area of cropland and convert it to a deep rooted mixture of native grasses. This WIRB funding is intended to be used to acquire a small area totaling 21.1 acres. It represents about 22% of the total local project effort. This will be added to the existing City well field of 40.2 acres and another piece of adjacent property, 35.34 acres, that the City recently acquired as part of an overall aggressive program to protect the community water supply. The City has a signed purchase agreement for 14.4 acres of the 21.1 and a strong verbal commitment to obtain the remaining 5.7 acres. This project has been very active for almost 2 years and is ready to implement immediately upon funding notification. The establishment of native grasses, funded by the local chapter of Pheasants Forever, will take approximately the next three years of operation & maintenance.
Resumo:
This report, entitled Iowa Highway Research and Development Activities FY 2015, is submitted in compliance with Iowa Code section 310.36 and 312.3A, which direct the submission of a report of the Secondary Road Research Fund and the Street Research Fund, respectively. It is a report of the status of research and development projects in process on June 30, 2015. It is also a report on projects completed during the fiscal year beginning July 1, 2014 and ending June 30, 2015. Detailed information on each of the research and development projects mentioned in this report is available from the office of Research and Analytics, Performance and Technology Division, Iowa Department of Transportation. All approved reports are also online for viewing at http://www.iowadot.gov/research/pdf/IHRBAnnualReport.pdf.
Resumo:
Visualization is a relatively recent tool available to engineers for enhancing transportation project design through improved communication, decision making, and stakeholder feedback. Current visualization techniques include image composites, video composites, 2D drawings, drive-through or fly-through animations, 3D rendering models, virtual reality, and 4D CAD. These methods are used mainly to communicate within the design and construction team and between the team and external stakeholders. Use of visualization improves understanding of design intent and project concepts and facilitates effective decision making. However, visualization tools are typically used for presentation only in large-scale urban projects. Visualization is not widely accepted due to a lack of demonstrated engineering benefits for typical agency projects, such as small- and medium-sized projects, rural projects, and projects where external stakeholder communication is not a major issue. Furthermore, there is a perceived high cost of investment of both financial and human capital in adopting visualization tools. The most advanced visualization technique of virtual reality has only been used in academic research settings, and 4D CAD has been used on a very limited basis for highly complicated specialty projects. However, there are a number of less intensive visualization methods available which may provide some benefit to many agency projects. In this paper, we present the results of a feasibility study examining the use of visualization and simulation applications for improving highway planning, design, construction, and safety and mobility.
Resumo:
Visualization is a relatively recent tool available to engineers for enhancing transportation project design through improved communication, decision making, and stakeholder feedback. Current visualization techniques include image composites, video composites, 2D drawings, drive-through or fly-through animations, 3D rendering models, virtual reality, and 4D CAD. These methods are used mainly to communicate within the design and construction team and between the team and external stakeholders. Use of visualization improves understanding of design intent and project concepts and facilitates effective decision making. However, visualization tools are typically used for presentation only in large-scale urban projects. Visualization is not widely accepted due to a lack of demonstrated engineering benefits for typical agency projects, such as small- and medium-sized projects, rural projects, and projects where external stakeholder communication is not a major issue. Furthermore, there is a perceived high cost of investment of both financial and human capital in adopting visualization tools. The most advanced visualization technique of virtual reality has only been used in academic research settings, and 4D CAD has been used on a very limited basis for highly complicated specialty projects. However, there are a number of less intensive visualization methods available which may provide some benefit to many agency projects. In this paper, we present the results of a feasibility study examining the use of visualization and simulation applications for improving highway planning, design, construction, and safety and mobility.
Resumo:
The Watershed Improvement Fund and the Iowa Watershed Improvement Review Board (WIRB) were created in 2005. This statute is now codified in Iowa Code Chapter 466A. The fifteen-member Board conducted seven meetings throughout the year in-person or via teleconference. Meetings were held January 23, February 27, April 17, June 18, July 24, September 25 and December 17. Attachment 1 lists the board members and their organization affiliation. The Board completed one Request For Applications (RFA) for the Watershed Improvement Fund. The RFA was announced November 6, 2014 and closed December 29, 2014. December 29, 2014 Closing Date Request For Applications: The Board received 16 applications in response to this RFA. These applications requested $2.8 million in Watershed Improvement Funds and leveraged an additional $9.1 million for a total of $11.9 million of watershed project activity proposed. After reviewing and ranking the applications individually from this RFA, the Board met and selected eight applications for funding. The eight applications were approved for $1,249,861 of Watershed Improvement Funds. Data on the eight selected projects in this RFA include the following: • These projects included portions of 12 counties. • The $1.2 million requested of Watershed Improvement Funds leveraged an additional $4.2 million for a total of $5.4 million in watershed improvements. • Approved projects ranged in funding from $41,980 to $250,000. Attachment 2 lists the approved projects’ name, applicant name, project length, county or counties where located, and funding amount for the RFA. Attachment 3 is a map showing the status of all projects funded since inception of the program. At the end of 2015 there are 111 completed projects and 39 active projects. In cooperation with the Treasurer of State, the WIRB submitted the 2015 year-end report for the Rebuild Iowa Infrastructure Fund to the Legislative Services Agency and the Department of Management. Attachment 4 contains the 2015 annual progress reports submitted from active projects or projects finished in 2015.
Resumo:
Tutkimus käsittelee tuotekehitys- ja innovaatioprosessin kehittämistä ja sen vakiinnuttamista kohdeyrityksissä A ja B. Työssä luodaan ensin kirjallisuustutkimuksena yleinen teoreettinen viitekehys ja lähtötilannemalli tuotekehitys- ja innovaatioprosessin referenssimallille. Tämän vaiheen aikanakäsitellään erilaisia elementtejä ja vaiheita, joita tarvitaan kehitysprosessinkuvaamiseen ja sen kehittämiseen. Prosessimallissa ovat keskeisessä osassa päätöspisteet, joiden arviointikriteereitä ja -tekniikoita työssä käsitellään osana portfolion hallinnan eri mahdollisuuksia. Kehitettyä teoreettista mallia lähdetään implementoimaan työn toisessa osassa kohdeyrityksiin A ja B. Implementoinninyhteydessä käydään läpi sekä prosessikuvaus että siihen liittyvät päätöskriteerit. Tutkimuksen lopputuloksena on yrityksille tuotettu esitys innovaatioprosessista ja sen eri osa-alueista tarkemmalla tasolla sekä tutkimuksen puitteissa rakennettu portfoliotyökalu, jolla kehitysprojekteja voidaan hallinnoida niiden eri vaiheissa.
Resumo:
Useilla toimialoilla kuten infra-alalla verkostoituminen on ollut vieras käsite. Hankintamallit, lainsäädäntö ja alalle ominaiset lyhytkestoiset projektit ovat olleet kumppanuuksien esteenä. Uudet hankintamallit ja toimijoille asetetut roolijakovaatimukset antavat infra-toimialan yrityksille mahdollisuuksia kumpanuuksien rakentamiseen. Tutkimuksen tavoitteena on löytää syitä ja motiiveja jotka johtavat verkostoitumiseen infra-alalla. Tutkimuksessa esitellään verkostoitumisen näkökulmasta käsin infra-alan keskeisen rakennuttaja-organisaation hankintastrategiaa, sekä siitä muodostettua alan arvoketjua. Verkostoituminen on prosessi, jonka aikana arvioidaan yrityksen kykyä toimia kumppanina. Vertikaalisen verkostoitumisen haasteena on yritysten välille syntyvä yhteinen näkemys toimintatavoista, joilla kahdenvälinen markkinaehtoinen liikesuhde voidaan muuttaa kumppanuudeksi. Tavoitteena on oikean tasapainon löytäminen hyötyjen ja haittojen välillä. Tutkimuksessa esitellään niitä hyötyjä ja haittoja, jotka liittyvät yritystenväliseen vertikaalisen verkostoitumiseen. Tutkimuksessa esitellään myös kaksi valmista verkostoitumistyökalua, jotka on tarkoitettu yritysten käyttöön verkostoitumisprosessin tueksi. Työkalut on valittu siten, että niiden käyttäminen on mahdollista ja hyödyllistä heti verkostoitumisprosessin alku- eli rakennusvaiheessa.