933 resultados para Foundations.


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The Federal Highway Administration (FHWA) mandated utilizing the Load and Resistance Factor Design (LRFD) approach for all new bridges initiated in the United States after October 1, 2007. To achieve part of this goal, a database for Drilled Shaft Foundation Testing (DSHAFT) was developed and reported on by Garder, Ng, Sritharan, and Roling in 2012. DSHAFT is aimed at assimilating high-quality drilled shaft test data from Iowa and the surrounding regions. DSHAFT is currently housed on a project website (http://srg.cce.iastate.edu/dshaft) and contains data for 41 drilled shaft tests. The objective of this research was to utilize the DSHAFT database and develop a regional LRFD procedure for drilled shafts in Iowa with preliminary resistance factors using a probability-based reliability theory. This was done by examining current design and construction practices used by the Iowa Department of Transportation (DOT) as well as recommendations given in the American Association of State Highway and Transportation Officials (AASHTO) LRFD Bridge Design Specifications and the FHWA drilled shaft guidelines. Various analytical methods were used to estimate side resistance and end bearing of drilled shafts in clay, sand, intermediate geomaterial (IGM), and rock. Since most of the load test results obtained from O-cell do not pass the 1-in. top displacement criterion used by the Iowa DOT and the 5% of shaft diameter for top displacement criterion recommended by AASHTO, three improved procedures are proposed to generate and extend equivalent top load-displacement curves that enable the quantification of measured resistances corresponding to the displacement criteria. Using the estimated and measured resistances, regional resistance factors were calibrated following the AASHTO LRFD framework and adjusted to resolve any anomalies observed among the factors. To illustrate the potential and successful use of drilled shafts in Iowa, the design procedures of drilled shaft foundations were demonstrated and the advantages of drilled shafts over driven piles were addressed in two case studies.

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Aquest treball té com a objectiu aprofundir en la relació que s’estableix entre escola i família i els elements que configuren aquesta, així com les estratègies implicades per tal que aquesta es doni de la manera adequada; als Serveis Educatius Municipals 0-6 de la ciutat de Pistoia. D’aquesta manera, juntament amb bases teòriques que ens contextualitzen i ens expliquen com funciona aquest aspecte dins del marc educatiu dels Serveis de la ciutat, trobem un anàlisi aprofundit d’aquesta relació en el dia a dia en dos d’aquests serveis, concretament un l’Asilo Nido i una Scuola dell’Infanzia.

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L’objectiu d’aquest treball és analitzar la inclusió d’un infant amb deficiència visual durant l’etapa d’Educació Infantil, amb la finalitat d’establir propostes de millora al centre encaminades a potenciar mesures per a la inclusió de tot l’alumnat. Per a la realització d’aquest estudi primerament ha estat necessari conèixer la fonamentació teòrica del concepte de visió i d’inclusió escolar, així com també les implicacions per part del centre, la família i l’entorn. Per a realitzar aquest anàlisi hem utilitzat entrevistes i pautes d’observació validades, amb la finalitat de conèixer més a fons la trajectòria de l’infant a l’etapa d’Educació Infantil, sempre des d’una concepció interaccionista, és a dir, tenint en compte l’àmbit escolar, familiar i l’entorn. I ja per acabar, aquest anàlisi ha servit per a proposar propostes de millora per a la inclusió de futurs alumnes en el centre.

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PURPOSE: The aim of this study was to develop models based on kernel regression and probability estimation in order to predict and map IRC in Switzerland by taking into account all of the following: architectural factors, spatial relationships between the measurements, as well as geological information. METHODS: We looked at about 240,000 IRC measurements carried out in about 150,000 houses. As predictor variables we included: building type, foundation type, year of construction, detector type, geographical coordinates, altitude, temperature and lithology into the kernel estimation models. We developed predictive maps as well as a map of the local probability to exceed 300 Bq/m(3). Additionally, we developed a map of a confidence index in order to estimate the reliability of the probability map. RESULTS: Our models were able to explain 28% of the variations of IRC data. All variables added information to the model. The model estimation revealed a bandwidth for each variable, making it possible to characterize the influence of each variable on the IRC estimation. Furthermore, we assessed the mapping characteristics of kernel estimation overall as well as by municipality. Overall, our model reproduces spatial IRC patterns which were already obtained earlier. On the municipal level, we could show that our model accounts well for IRC trends within municipal boundaries. Finally, we found that different building characteristics result in different IRC maps. Maps corresponding to detached houses with concrete foundations indicate systematically smaller IRC than maps corresponding to farms with earth foundation. CONCLUSIONS: IRC mapping based on kernel estimation is a powerful tool to predict and analyze IRC on a large-scale as well as on a local level. This approach enables to develop tailor-made maps for different architectural elements and measurement conditions and to account at the same time for geological information and spatial relations between IRC measurements.

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Problems with unknown bridge foundations in Iowa are often associated with timber substructures. Timber piles are subject to biological and physical deterioration, which makes quantifying in-service pile capacity difficult. Currently there are no reliable means to estimate the residual carrying capacity of an in-service deteriorated pile; and thus, the overall safety of the bridge cannot be determined. The lack of reliable evaluation methods can lead to conservative and costly maintenance practices. This research study was undertaken to investigate procedures for assessing bridge substructures, and evaluating procedures for rehabilitating/strengthening/replacing inadequate substructure components. The report includes an extensive literature review, a field reconnaissance study of 49 bridges, a survey of substructure problems from the perspective of County Engineers, a laboratory study aiming to correlate nondestructive tests to residual pile strength and stiffness values, nondestructive and destructive load tests for 6 bridges with poor substructures, and finally a laboratory study evaluating selected repair methods.

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The performance of a pavement depends on the quality of its subgrade and subbase layers; these foundational layers play a key role in mitigating the effects of climate and the stresses generated by traffic. Therefore, building a stable subgrade and a properly drained subbase is vital for constructing an effective and long lasting pavement system. This manual has been developed to help Iowa highway engineers improve the design, construction, and testing of a pavement system’s subgrade and subbase layers, thereby extending pavement life. The manual synthesizes current and previous research conducted in Iowa and other states into a practical geotechnical design guide [proposed as Chapter 6 of the Statewide Urban Design and Specifications (SUDAS) Design Manual] and construction specifications (proposed as Section 2010 of the SUDAS Standard Specifications) for subgrades and subbases. Topics covered include the important characteristics of Iowa soils, the key parameters and field properties of optimum foundations, embankment construction, geotechnical treatments, drainage systems, and field testing tools, among others.

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This report describes a study to evaluate Geopier® soil reinforcement technology in transportation construction. Three projects requiring settlement control were chosen for evaluation—an embankment foundation, a box culvert, and a bridge approach fill. For each project, construction observations, in situ soil testing, laboratory material characterization, and performance monitoring were carried out. For the embankment foundation project, Geopier elements were installed within and around an abutment footprint for the new I-35 overpass at the US Highway 5/Interstate 35 interchange in Des Moines, Iowa. Although the main focus of this investigation was to evaluate embankment foundation reinforcement using Geopier elements, a stone column reinforced soil provided an opportunity to compare systems. In situ testing included cone penetration tests (CPTs), pressuremeter tests (PMTs), Ko stepped blade tests, and borehole shear tests (BSTs), as well as laboratory material testing. Comparative stiffness and densities of Geopier elements and stone columns were evaluated based on full-scale modulus load tests and standard penetration tests. Vibrating wire settlement cells and total stress cells were installed to monitor settlement and stress concentration on the reinforcing elements and matrix soil. Settlement plates were also monitored by conventional optical survey methods. Results show that the Geopier system and the stone columns performed their intended functions. The second project involved settlement monitoring of a 4.2 m wide x 3.6 m high x 50 m long box culvert constructed beneath a bridge on Iowa Highway 191 south of Neola, Iowa. Geopier elements were installed to reduce total and differential settlement while ensuring the stability of the existing bridge pier foundations. Benefits of the box culvert and embankment fill included (1) ease of future roadway expansion and (2) continual service of the roadway throughout construction. Site investigations consisted of in situ testing including CPTs, PMTs, BSTs, and dilatometer tests. Consolidated drained triaxial compression tests, unconsolidated undrained triaxial compression test, oedometer tests, and Atterberg limit tests were conducted to define strength and consolidation parameters and soil index properties for classification. Vibrating wire settlement cells, total stress cells, and piezometers were installed for continuous monitoring during and after box culvert construction and fill placement. This project was successful at controlling settlement of the box culvert and preventing downdrag of the bridge foundations, but could have been enhanced by reducing the length of Geopier elements at the ends of the box culvert. This would have increased localized settlement while reducing overall differential settlement. The third project involved settlement monitoring of bridge approach fill sections reinforced with Geopier elements. Thirty Geopier elements, spaced 1.8 m apart in six rows of varying length, were installed on both sides of a new bridge on US Highway 18/218 near Charles City, Iowa. Based on the results of this project, it was determined that future applications of Geopier soil reinforcement should consider extending the elements deeper into the embankment foundation fill, not just the fill itself.

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The early-age thermal development of structural mass concrete elements has a significant impact on the future durability and longevity of the elements. If the heat of hydration is not controlled, the elements may be susceptible to thermal cracking and damage from delayed ettringite formation. In the Phase I study, the research team reviewed published literature and current specifications on mass concrete. In addition, the team observed construction and reviewed thermal data from the westbound (WB) I-80 Missouri River Bridge. Finally, the researchers conducted an initial investigation of the thermal analysis software programs ConcreteWorks and 4C-Temp&Stress. The Phase II study is aimed at developing guidelines for the design and construction of mass concrete placements associated with large bridge foundations. This phase included an additional review of published literature and a more in-depth investigation of current mass concrete specifications. In addition, the mass concrete construction of two bridges, the WB I-80 Missouri River Bridge and the US 34 Missouri River Bridge, was documented. An investigation was conducted of the theory and application of 4C-Temp&Stress. ConcreteWorks and 4C-Temp&Stress were calibrated with thermal data recorded for the WB I-80 Missouri River Bridge and the US 34 Missouri River Bridge. ConcreteWorks and 4C-Temp&Stress were further verified by means of a sensitivity study. Finally, conclusions and recommendations were developed, as included in this report.

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The goals of this project were to implement several stabilization methods for preventing or mitigating freeze-thaw damage to granular surfaced roads and identify the most effective and economical methods for the soil and climate conditions of Iowa. Several methods and technologies identified as potentially suitable for Iowa were selected from an extensive analysis of existing literature provided with Iowa Highway Research Board (IHRB) Project TR-632. Using the selected methods, demonstration sections were constructed in Hamilton County on a heavily traveled two-mile section of granular surfaced road that required frequent maintenance during previous thawing periods. Construction procedures and costs of the demonstration sections were documented, and subsequent maintenance requirements were tabulated through two seasonal freeze-thaw periods. Extensive laboratory and field tests were performed prior to construction, as well as before and after the two seasonal freeze-thaw periods, to monitor the performance of the demonstration sections. A weather station was installed at the project site and temperature sensors were embedded in the subgrade to monitor ground temperatures up to a depth of 5 ft and determine the duration and depths of ground freezing and thawing. An economic analysis was performed using the documented construction and maintenance costs, and the estimated cumulative costs per square yard were projected over a 20-year timeframe to determine break-even periods relative to the cost of continuing current maintenance practices. Overall, the sections with biaxial geogrid or macadam base courses had the best observed freeze-thaw performance in this study. These two stabilization methods have larger initial costs and longer break-even periods than aggregate columns, but counties should also weigh the benefits of improved ride quality and savings that these solutions can provide as excellent foundations for future paving or surface upgrades.

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Internet s'ha convertit en una font extraordinària de recursos per una audiència en constant creixement arreu el món. A l'igual que en altres activitats de la nostra societat, el coneixement de la localització geogràfica d'aquests recursos i de la gent que hi accedeix és útil tant pels usuaris com pels proveïdors d'informació. La geolocalització IP, però, pot donar informació errònia o amb un nivell de precisió que no vagi més enllà de la referència a un país.Aquest treball recull els diferents actors que formen part de la geolocalització IP i s'ha analitzat el paper que juguen en aquest procés així com la seva influència en el nivell de fiabilitat i exactitud final. Amb aquests sòlids fonaments s'ha desenvolupat una aplicació per representar gràficament en un mapa la geolocalització IP d'un dispositiu i la dels nodes que formen el camí realitzat fins arribar-hi, així com tota la informació addicional que de cada IP s'ha pogut obtenir.El resultat ha estat una memòria tècnica de tot el treball de recerca juntament amb una aplicació que s'executa en l'entorn de Microsoft Windows i plataforma .NET, caracteritzada per la seva facilitat d'ús gràcies a un disseny simple molt intuïtiu i efectiu, la rapidesa d'execució per què aprofita la programació de fils, i un positiu impacte visual ja que fa servir l'API de Google Maps per a la representació visual de la traça.

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Tutkimuksen tavoitteena oli selvittää Keskuskauppakamarin tilintarkastuslautakunnan ja Valtion tilintarkastuslautakunnan valvontaratkaisujen vaikutusta hyvään tilintarkastustapaan. Tavoitteeseen päästiin alatavoitteiden kautta: a) selvittämällä tilintarkastukselle asetetut vaatimukset ja tilintarkastajien valvonnan periaatteet, b) tarkastelemalla valvontaratkaisujen kautta tilintarkastajien velvollisuuksia: riippumattomuutta, salassapitovelvollisuutta sekä ammattitaitoa ja huolellisuutta, c) tutkimalla, millaisia seikkoja Keskuskauppakamarin tilintarkastuslautakunta ja Valtion tilintarkastuslautakunta korostavat ja nostavat esiin valvontaratkaisujen yhteydessä d) tutkimalla, mihin edellä mainitut valvontaorganisaatiot kiinnittävät huomiota valvontaratkaisujen käsittelyssä ja mihin päätökset perustuvat. Tutkimus on luonteeltaan kvalitatiivinen ja deskriptiivinen. Se on myös normiperustainen, koska tilintarkastuksen taustalla vaikuttavat erilaiset lait, asetukset ja suositukset. Tutkimuksen empiirinen aineisto koostuu Keskuskauppakamarin tilintarkas tuslautakunnan ja Valtion tilintarkastuslautakunnan valvontaratkaisuselosteista vuosilta 1995-2004. Tutkimuksen perusteella valvontaratkaisut muokkaavat hyvää tilintarkastustapaa. Tilintarkastuslautakunta julkaisee ratkaisujen johdosta kannanottoja, antaa tarvittaessa tilintarkastusalan säännöstöä täydentäviä suosituksia ja ohjeita sekä esittää oman kannanottonsa tulkinnanvaraisiin seikkoihin. Valvontaratkaisut perustuvat voimassa olevaan säädöstöön, tilintarkastusalan suosituksiin ja toimielinten aiempiin ratkaisuihin. Tilintarkastajien toiminnan arvioinnissa tilintarkastajan tekemän virheen olennaisuudella on keskeinen merkitys. Lisäksi arvioinnissa kiinnitetään erityisesti huomiota tilintarkastajien toimintaan kokonaisuutena ja siihen, onko ulkopuolinen voinut saada virheen johdosta väärän käsityksen. Ratkaisuissa korostuu säätiöiden, julkisen kaupankäynnin kohteena olevien yhtiöiden sekä erikoistarkastusten erityinen tarkastusvastuu.

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Tämän diplomityön päätavoitteena oli laatia katsastusalan yritykselle liiketoimintasuunnitelma, joka luo perustan yrityksen johtamiselle ja jatkokehittämiselle.Katsastus Kovalainen Oy tarvitsee jatkuvaan käyttöönsä yrityksen toimintaa ohjaavan viitekehyksen. Ensimmäisenä alaongelmana oli selvittää, mitä liiketoiminnaneri osa-alueita liiketoimintasuunnitelma käsittelee? Onnistuneen liiketoimintasuunnitelman yhtenä peruspilarina voidaan pitää sitä, kuinka hyvin se soveltuu kohdeyrityksen käyttöön ja onko sen sisältämä tieto oleellista juuri kohdeyritykselle? Toinen alaongelma ratkaistiin vastaamalla kysymykseen: Millä tavoin yrityksestä ja sen toimintaympäristöstä kyetään erottamaan juuri se oleellisin tieto liiketoimintasuunnitelman luomiseksi? Kolmanneksi alaongelmaksi muodostui kysymys siitä, kuinka liiketoimintasuunnitelman viitekehys ja empiirinen tieto yhdistetään toimivaksi kokonaisuudeksi, jota yritys voi hyödyntää. Työn teoriaosuus on tehty kirjallisuustutkimuksena ja siinä esitellään liiketoimintasuunnitelmaan kuuluvat osa-alueet teorian näkökulmasta. Empiirisen osuuden tiedot on kerätty pääasiassa haastatteluiden avulla. Empiiristä aineistoa on kerätty myös käyttämällä hyväksi jo olemassa olevaa dokumentoitua tietoa yrityksestä, kuten yrityksen tilinpäätös- ja markkinaosuusraportteja. Liiketoimintasuunnitelmaan kuuluva yrityksen sisäinen analyysi auttoi yrityksen johtoa identifioimaan ja priorisoimaan ne toiminnot ja tekijät, jotka eniten vaikuttavat yrityksen menestymiseen ja kilpailukykyyn. Kyseisen analysoinnin avulla huomattiin, että suurimmat puutteet ja kehitystoimenpiteet koskivat Katsastus Kovalaisen markkinointia ja katsastustiloja.Toimintaympäristön analysoinnin tuloksena huomattiin, että Katsastus Kovalaisenmarkkinaosuus on jo 40 prosenttia, jota voidaan pitää sen verran suurena, että tärkeimmäksi tekijäksi tulevaisuudessa katsottiin nykyisen markkinaosuuden säilyttäminen muun muassa pitämällä nykyiset asiakkaat tyytyväisenä.

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Independent regulatory agencies are the institutional foundations of the regulatory state that, during the past 15 years, has gained prominence throughout Europe. This article studies the rise of independent authorities in European countries by comparing regulatory agencies and central banks. Delegation to independent central banks and to independent regulatory agencies is similar in many respects. In both cases, agents are deliberately made independent from political principals through a specific institutional design. Moreover, it has been argued that delegation to both central banks and regulatory agencies is linked to the need for policy-makers to improve the credibility of policy commitments, to the wish of incumbent politicians to tie the hands of future majorities, and to the extent to which the institutional contexts safeguard policy stability. Through an analysis of the formal independence of central banks and regulatory agencies in Western Europe, this article identifies an empirical puzzle that casts doubts on the accuracy of current explanations. Veto players and the uncertainty of incumbent policy-makers in respect to their re-election prospects matter for delegation to both central banks and regulatory agencies, but in opposite ways. Making sense of these anomalies is necessary to achieve a better understanding of delegation to independent authorities.