Dynamic Behavior and Fatigue Life of Highway Bridges Due to Doubling Heavy Vehicles

An increase in the demand for the freight shipping in the United States has been predicted for the near future and Longer Combination Vehicles (LCVs), which can carry more loads in each trip, seem like a good solution for the problem. Currently, utilizing LCVs is not permitted in most states of the US and little research has been conducted on the effects of these heavy vehicles on the roads and bridges. In this research, efforts are made to study these effects by comparing the dynamic and fatigue effects of LCVs with more common trucks. Ten Steel and prestressed concrete bridges with span lengths ranging from 30’ to 140’ are designed and modeled using the grid system in MATLAB. Additionally, three more real bridges including two single span simply supported steel bridges and a three span continuous steel bridge are modeled using the same MATLAB code. The equations of motion of three LCVs as well as eight other trucks are derived and these vehicles are subjected to different road surface conditions and bumps on the roads and the designed and real bridges. By forming the bridge equations of motion using the mass, stiffness and damping matrices and considering the interaction between the truck and the bridge, the differential equations are solved using the ODE solver in MATLAB and the results of the forces in tires as well as the deflections and moments in the bridge members are obtained. The results of this study show that for most of the bridges, LCVs result in the smallest values of Dynamic Amplification Factor (DAF) whereas the Single Unit Trucks cause the highest values of DAF when traveling on the bridges. Also in most cases, the values of DAF are observed to be smaller than the 33% threshold suggested by the design code. Additionally, fatigue analysis of the bridges in this study confirms that by replacing the current truck traffic with higher capacity LCVs, in most cases, the remaining fatigue life of the bridge is only slightly decreased which means that taking advantage of these larger vehicles can be a viable option for decision makers.

Práticas pedagógicas e inclusão escolar: o processo de ensino-aprendizagem de alunas com deficiência intelectual

This research aimed to know and analyze the pedagogical practices that have been developed in the teaching and learning of students with Intellectual Disability (DI), enrolled at common class of elementary school I. The study was conducted in a public school at Natal/RN, involving two students with DI, a multipurpose teacher, a teaching assistant, a teacher of arts and educational coordinator. As for methodological choice, we chose to develop a qualitative study, undertaking a case study. As tools for the construction of the data we use: semi-structured interviews, participant observation, field diary and document analysis. Data analysis reveals that the institution in which the research was undertaken gradually implementing changes in order to develop an inclusive practice, consistent with its assumptions. Regarding the practices developed in the teaching and learning of students with intellectual disabilities, it was possible to realize the fulfillment of certain adjustments in relation to the objectives, activities and some content, involving the use of resources and varied strategies. With regard to educational activities, we found that these had different levels of complexity, covering both basic goals as more complex objectives. From the observations, we realize that the Assistant Professor of mediations during varied activities as challenging tool in intellectual processes. We note, too, a dynamic classroom in which disabled students were under the guidance of Assistant Professor, and other students with all-round teacher who had a fairly traditional teaching methodology. It created thus an isolation situation, since there was no proposition practices to be developed with all students, and interaction among classmates, generally quite restricted. Although were highlighted developments in the social and academic learning of the surveyed students, the teachers said they did not feel prepared to work freight inclusion. The study reveals the need for teachers reviewing some actions undertaken, in order to develop more democratic pedagogical practices of education, stimulating the interactions between students, by proposing challenging activities that promote the formation and concepts. In addition, it points to the need of the education system invest and encourage the qualification of teachers with regard to education in an inclusive perspective, through actions that promote lifelong learning. It needs to be developed on the teacher a reflective attitude, resulting in a view that due diligence must be entered in practice inherent in teaching in order to use to enhance their educational experience.

Práticas pedagógicas e inclusão escolar: o processo de ensino-aprendizagem de alunas com deficiência intelectual

This research aimed to know and analyze the pedagogical practices that have been developed in the teaching and learning of students with Intellectual Disability (DI), enrolled at common class of elementary school I. The study was conducted in a public school at Natal/RN, involving two students with DI, a multipurpose teacher, a teaching assistant, a teacher of arts and educational coordinator. As for methodological choice, we chose to develop a qualitative study, undertaking a case study. As tools for the construction of the data we use: semi-structured interviews, participant observation, field diary and document analysis. Data analysis reveals that the institution in which the research was undertaken gradually implementing changes in order to develop an inclusive practice, consistent with its assumptions. Regarding the practices developed in the teaching and learning of students with intellectual disabilities, it was possible to realize the fulfillment of certain adjustments in relation to the objectives, activities and some content, involving the use of resources and varied strategies. With regard to educational activities, we found that these had different levels of complexity, covering both basic goals as more complex objectives. From the observations, we realize that the Assistant Professor of mediations during varied activities as challenging tool in intellectual processes. We note, too, a dynamic classroom in which disabled students were under the guidance of Assistant Professor, and other students with all-round teacher who had a fairly traditional teaching methodology. It created thus an isolation situation, since there was no proposition practices to be developed with all students, and interaction among classmates, generally quite restricted. Although were highlighted developments in the social and academic learning of the surveyed students, the teachers said they did not feel prepared to work freight inclusion. The study reveals the need for teachers reviewing some actions undertaken, in order to develop more democratic pedagogical practices of education, stimulating the interactions between students, by proposing challenging activities that promote the formation and concepts. In addition, it points to the need of the education system invest and encourage the qualification of teachers with regard to education in an inclusive perspective, through actions that promote lifelong learning. It needs to be developed on the teacher a reflective attitude, resulting in a view that due diligence must be entered in practice inherent in teaching in order to use to enhance their educational experience.

A review of road structure data in six European countries

The European Union has expanded significantly in recent years. Sustainable trade within the Union, leading to economic growth to the benefit of the ‘old’ and ‘new’ member states is thus extremely important. The road infrastructure is strategic and vital to such development since an uneven transport infrastructure, in terms of capacity and condition, has the potential to reinforce uneven development trends and hinder economic convergence of old and new member states. In the decades since their design and construction, loading conditions have significantly changed for many major highway infrastructure elements/networks owing primarily to increased freight volumes and vehicle sizes. This, coupled with the gradual deterioration of a significant number of highway structures due to their age, and the absence of a pan-European assessment framework, can be expected to affect the smooth functioning of the infrastructure in its as-built condition. Increased periods of reduced flow can be expected owing to planned and unplanned interventions for repair/rehabilitation. This paper reports the findings of a survey regarding the current status of the highway infrastructure elements in six countries within the European Union as reported by the owners/operators. The countries surveyed include a cross-section of ‘existing’ older countries and ‘new’ member states. The current situations for bridges, culverts, tunnels and retaining walls are reported, along with their potential replacement costs. The findings act as a departure point for further studies in support of a centralised and/or synchronised EU approach to infrastructure maintenance management. Information in the form presented in this paper is central to any future decision-making frameworks in terms of trade route choice and operations, monetary investment, optimised maintenance, management and rehabilitation of the built infrastructure and the economic integration of the newly joined member states.

Ice observations in the Southern Ocean between 1878 and 1928

During the period in question, large ice drifts transported incalculable numbers of icebergs, ice fields and ice floes from the Antarctica into the South Atlantic, confronting long-journeying sailing ships on the Cape Horn route with considerable danger. As is still the case today, the ice drifts generally tended in a northeasterly direction. Thus it can be assumed that the ice masses occuring near Cape Horn and in the South Atlantic originated in Graham Land and the South Shetland Islands, while those found in the Pacific will have come from Victoria Land. The masses drifting to Cape Horn, Isla de los Estados, the Falkland Islands and occasionally as far as the Tristan da Cunha Group are transported by the West Wind Drift and Falkland Current, diverted by the Brazil Current. The Bouvet and Agulhas Currents have little influence here. The great ice masses repeatedly reached points beyond the "outermost drift ice boundery" calculated in the course of the years, to continue on in the direction of the equator. The number of sailing ships which fell victim to the ice drifts while rounding Cape Horn can only be surmised; they simply disappeared without a trace in the expanses of the South Atlantic. Until the end of the 1900s the dangers presented by ice were less serious for westward-bound ships than for the "homeward-bounders" travelling from West to East. Following the turn of the century, however, the risk for "onwardbounders" increased significantly. Whether the ice drifts actually grew in might or whether the more frequent and more detailed reports led to this impression, could never be ascertained by the German Hydrographie Office. In the forty-one years between 1868 and 1908, ten light, ten medium and nine heavy ice years were counted, and only twelve years in which no reports of ice were submitted to the German Hydrographie Office. "One of the most terrible dangers threatening ships on their return from the Pacific Ocean," the pilot book for the Atlantic Ocean warns, "is the encounter with ice, to be expected south of the 50th parallel (approx.) in the Pacific and south of the 40th parallel (approx.) in the South Atlantic." Following the ice drift of 1854-55, thought to be the first ever recorded, the increasing numbers of sailing ships rounding Cape Horn were frequently confronted with drifts of varying sizes or with single icebergs. Then from 1892-94, a colossal ice drift crossed the path of the sailships in three stages. Several sailing ships collided with the icebergs and could be counted lucky if they survived with heavy damage to the bow and the fo regear. The reports on those which vanished for ever in the ice masses are hardly of investigative value. The English suffered particularly badly in the ice-plagued waters; their captains apparently sailed courses that led more freqently through drifts than did the sailing instructions of the German Hydrographic Office. Thus, among others, Capt. Jarvis' DUNTRUNE, also the STANMORE, ARTHURSTONE and LORD RANOCH as well as the French GALATHEE and CASHMERE all collided with icebergs. The crew of the AETHELBERTH panicked after a collision and took to their lifeboats. It was only after the ship detached itself from the iceberg it had rammed that the men returned to it and continued their journey. The TEMPLEMORE, on the other hand, had to be abandoned for good. Of the German sailing ships, the FLOTOW is to be mentioned here, and in the third phase of the drift the American SAN JOAQUIN lost a large proportion of its rigging. In the 20th century ice drifts continued to cross the courses of the Cape Horn ships. 1906 and 1908 were recorded as particularly heavy ice years. In 1908-09 both the FALKLANDBANK and the TOXTETH fell prey to ice, or so it was assumed during the subsequent Maritime Board proceedings. For the most part the German sailing ships were spared greater damages by sea. Their captains sent detailed ice reports to the German Hydrographic Office, which gratefully welcomed the information and partially incorporated it in the third and final edition of the "Pilot Book for the Atlantic Ocean." From the end of 1926 until the beginning of 1928, the last of the large sailing ships were once again confronted with "tremendous masses of icebergs and ice drifts." Reports of this period originated above all on the P-Liners PADUA, PAMIR, PASSAT, PEKING, PINNAS, PRIWALL and the ships of Gustav Erikson's fleet. The fate of the training sailship ADMIRAL KARPFANGER in connection with the ice in early 1938 was never clearly determined by the Maritime Board proceedings. Collision with an iceberg, however, is thought to be the most likely cause of accident. Today freight sailing ships no longer cross the oceans. The Cape Horn route is relatively insignificant for engine-powered ships and icebergs can be spotted in plenty of time by modern navigation technology ... The large ice drifts are no longer a menace, but only a marginal note in the final chapter of the history of transoceanic sailing.

Investigation of the Impact of Dual-Lane Axle Spacing on Lateral Load Distribution, 2016

The spacing of adjacent wheel lines of dual-lane loads induces different lateral live load distributions on bridges, which cannot be determined using the current American Association of State Highway and Transportation Officials (AASHTO) Load and Resistance Factor Design (LRFD) or Load Factor Design (LFD) equations for vehicles with standard axle configurations. Current Iowa law requires dual-lane loads to meet a five-foot requirement, the adequacy of which needs to be verified. To improve the state policy and AASHTO code specifications, it is necessary to understand the actual effects of wheel-line spacing on lateral load distribution. The main objective of this research was to investigate the impact of the wheel-line spacing of dual-lane loads on the lateral load distribution on bridges. To achieve this objective, a numerical evaluation using two-dimensional linear elastic finite element (FE) models was performed. For simulation purposes, 20 prestressed-concrete bridges, 20 steel bridges, and 20 slab bridges were randomly sampled from the Iowa bridge database. Based on the FE results, the load distribution factors (LDFs) of the concrete and steel bridges and the equivalent lengths of the slab bridges were derived. To investigate the variations of LDFs, a total of 22 types of single-axle four-wheel-line dual-lane loads were taken into account with configurations consisting of combinations of various interior and exterior wheel-line spacing. The corresponding moment and shear LDFs and equivalent widths were also derived using the AASHTO equations and the adequacy of the Iowa DOT five-foot requirement was evaluated. Finally, the axle weight limits per lane for different dual-lane load types were further calculated and recommended to complement the current Iowa Department of Transportation (DOT) policy and AASHTO code specifications.

Highway Performance and Time-Sensitive Industries, 1998

This report addresses delays to freight shippers. Although the focus is on just-in-time (JIT) businesses, the authors also note that non JIT businesses also suffer delays that impact their productivity. The table of contents lists the following headings: chapter 1 - introduction - a trial application: the Des Moines metropolitan area; structure of the report; chapter 2 - reliability at the forefront of freight transport demand - manufacturing and inventory; just-in-time operations in the U.S.; transportation consequences; summary; chapter 3 - JIT operations in Iowa - survey and sample; trucking activity and service; just-in-time truck transportation in Iowa; assessment of factors affecting truck transportation service; summary and conclusions; chapter 4 - travel time uncertainty induced by incidents - a probabilistic model for incident occurrences and durations; calculation of delay; trial application; conclusions; and chapter 5 - conclusions and recommendations - conclusions; recommendations.

Estimates of Total Fuel Consumption in Transporting Grain from Iowa to Major Grain-Importing Countries by Alternative Modes and Routes, 1985

This study measured fuel consumption in transporting grain from Iowa origins to Japan and Amsterdam by alternative routes and modes of transport and applied these data to construct equations for fuel consumption from Iowa origins to alternative final destinations. Some of the results are as follows: (1) The metered tractor-trailer truck averaged 186.6 gross ton-miles per gallon and 90.5 net ton-miles per gallon when loaded 50% of total miles. (2) The 1983 fuel consumption of seven trucks taken from company records was 82.4 net ton-miles per gallon at 67.5% loaded miles and 68.6 net ton-miles per gallon at 50% loaded miles. (3) Unit grain trains from Iowa to West Coast ports averaged 437.0 net ton-miles per gallon whereas unit grain trains from Iowa to New Orleans averaged 640.1 net ton-miles per gallon--a 46% advantage for the New Orleans trips. (4) Average barge fuel consumption on the Mississippi River from Iowa to New Orleans export grain elevators was 544.5 net ton-miles per gallon, with a 35% backhaul rate. (5) Ocean vessel net ton-miles per gallon varies widely by size of ship and backhaul percentage. With no backhaul, the average net ton-miles per gallon were as follows: for 30,000 dwt ship, 574.8 net ton-miles per gallon; for 50,000 dwt ship, 701.9; for 70,000 dwt ship, 835.1; and for 100,000 dwt ship, 1,043.4. (6) The most fuel efficient route and modal combination to transport grain from Iowa to Japan depends on the size of ocean vessel, the percentage of backhaul, and the origin of the grain. Alternative routes and modal combinations in shipping grain to Japan are ranked in descending order of fuel efficiencies.

The Iowa Grain Flow Survey: Where and How Iowa Grain Producers and Country Elevators Shipped Corn and Soybeans During September 1, 1999 - August 31, 2000, 2001

In September 1996, a grain flow survey consisting of two parts was completed and published. One part was a farm-to-market survey from a sample of Iowa grain producers, and the second was a survey of all Iowa country elevators. An updated survey for the crop year September 1, 1999 -August 31, 2000, was initiated in September 2000. The results of the two updated surveys are presented in this report. The purpose of the surveys is to estimate the amount of Iowa corn and soybeans that are shipped from each crop reporting district to each major market. Copies of the two questionnaires are presented in the appendices.

Keskisuurten tieliikenteen tavarankuljetusyritysten keskeisimmät menestystekijät

Tämän kandidaatintutkielman tarkoituksena on tarkastella suomalaista tieliikenteen tavarankuljetusalaa ja tällä toimialla menestymistä. Tutkielman päätavoitteena on selvittää, mitkä ovat keskisuurten tieliikenteen tavarankuljetusyritysten keskeisimmät menestykseen vaikuttavat tekijät. Tutkielma on rajattu koskemaan suomalaisia 20-50 henkilöä työllistäviä tieliikenteen tavarankuljetusyrityksiä. Tutkimus toteutettiin kvalitatiivisesti ja tutkimuksen aineisto kerättiin puolistrukturoidun teemahaastattelun avulla. Tutkielmassa haastateltiin viittä toimitusjohtajaa rajausten mukaisista yrityksistä. Tämän tutkielman tulosten mukaan keskisuurten tieliikenteen tavarankuljetusyritysten keskeisimmät menestystekijät ovat keskittyminen ja erikoistuminen. Erikoistumisella tarkoitetaan erikoistumista johonkin tiettyyn kuljetuslajiin. Keskittymisellä tarkoitetaan pitkäjänteistä keskittymistä arvoa luoviin toimintoihin sekä yrityksen harjoittamaan kuljetuslajiin. Muita yksittäisiä menestystekijöitä olivat muun muassa: kaluston tuottavuuden parantaminen, työntekijöiden tuottavuuden parantaminen, hyvä kustannusjohtaminen, asiakassuhteiden hyvä johtaminen ja pätevien työntekijöiden pitäminen yrityksessä. Tutkielman tuloksissa havaittiin myös, että yrityksen harjoittaman kuljetuslajin vaikutus liiketoiminnan menestykseen todennäköisesti kasvaa tulevaisuudessa kabotaasin vapauttamisen myötä. Tutkielman tulosten yleistettävyyteen on suhtauduttava kuitenkin kriittisesti tutkielman pienestä otoksesta johtuen.

Modified atmosphere packaging effects on the postharvest quality of papaya fruit

Export of Fijian papaya (Carica papaya) fruit to destinations such as New Zealand has increased significantly over the last several years. Shipment by sea rather than air is the preferred method, given the capacity for larger volumes and reductions in cost. Long shipping times, however, can compromise fruit quality, although the use of modified atmosphere packaging (MAP) may provide a viable solution for extending fruit storage life. In a collaborative ACIAR project, Australian and Fijian researchers investigated the potential of using MAP to extend storage life of a Fijian papaya ('Fiji Red') fruit based on simulated sea transport conditions. Fruit were packed in one of three MAP environments within cartons, consisting of either a (1) Low Density Polyethylene (LDPE) bag with 10 g of KMnO4, (2) Polyamide Film (PF) bag with macro-perforations or (3) without a bag (control fruit). Fruit were held for 1, 2 or 3 weeks at 10°C before being unpacked, ripened and assessed for quality. On day 6 after outturn, fruit with the highest overall quality were those held in LDPE bags. LDPE fruit generally coloured up faster at outturn than PF or control fruit, had less overall moisture loss and scored high in flavour. Headspace carbon dioxide and oxygen concentrations within the LDPE bags were also near recommended levels for maintaining optimum storage-life quality. The LDPE bag provided the most suitable conditions for long term storage of fresh papaya fruit and is therefore the recommended MAP type for use with sea freight export out of Fiji.

The spatial dimension of cycle logistics

US Cycle logistics is emerging as a promising alternative in urban freight transport. Compared to fossil fuelled vans, the use of cycles for delivering goods within urban areas offers advantages in terms of environmental friendliness, economic efficiency, flexibility, and liveability of urban neighbourhood. At the same time, cycle logistics has to face limits in terms of weight and volume of goods that can be delivered, distances that can be covered, and spatial urban structures that can be served. This latter issue has till now received less attention in the scientific literature: it is generally recognized that cycle logistics performs at its best in inner urban areas, but no systematic study has been realized to identify specific spatial requisites for the effectiveness of cycle logistics. This paper provides a brief review of the main issues that emerge from the literature over cycle logistics, and contributes to stimulate the debate over the spatial dimension of cycle logistics: it presents a classification of cycle logistics schemes, on the basis of their integration with other urban logistic facilities and of the spatial structure of delivery operations. A three-level classification is proposed, depending on the type of goods consolidation: only distribution without consolidation, consolidation in a fixed urban consolidation centre, or consolidation in a mobile depot; for each level, operational examples and case studies are provided. This systematizing typology could support both public and private operators in decisions about the organization of cycle logistics facilities, such as the location of urban consolidation centres or the composition of cycle fleets.

On the study of train-track dynamic interactions caused by rail welds on discrete supported rails

The paper studies the influence of rail weld dip on wheel-rail contact dynamics, with particular reference to freight trains where it is important to increase the operating speed and also the load transported. This has produced a very precise model, albeit simple and cost-effective, which has enabled train-track dynamic interactions over rail welds to be studied to make it possible to quantify the influence on dynamic forces and displacements of the welding geometry; of the position of the weld relative to the sleeper; of the vehicle's speed; and of the axle load and wheelset unsprung mass. It is a vertical model on the spatial domain and is drawn up in a simple fashion from vertical track receptances. For the type of track and vehicle used, the results obtained enable the quantification of increases in wheel-rail contact forces due to the new speed and load conditions.

Profesionalización del conductor de camión como factor crítico de éxito de una compañía de transporte terrestre de carga en Colombia

La implementación de un programa de profesionalización de conductores en una compañía de transporte terrestre de carga en Colombia, es una iniciativa, que además de producir ahorros energéticos al país, contribuye a la protección del medio ambiente y a la seguridad en las vías -- Al interior de las compañías de transporte terrestre de carga se generan importantes ahorros por menor consumo de combustible, menores costos de mantenimiento, mayor bienestar a los conductores; así como mayor disponibilidad y confiabilidad de los equipos para operar -- El trabajo de grado del que trata este documento tiene como propósito presentar un programa de profesionalización del conductor de camión en empresa de transporte terrestre de carga, en donde se identifican y definen cuáles son las etapas más importantes que debe incluir un programa de profesionalización de conductores en Colombia, y adicionalmente, se realiza valoración de la importancia de cada etapa dentro del programa -- El programa de profesionalización de conductores tiene como foco las personas, reconoce y valora su gran contribución al desempeño exitoso de las compañías de transporte, es por esto que el programa se fundamenta en teorías administrativas de motivación, clima organizacional, incentivo; al igual que teorías administrativas como ventaja competitiva, valor compartido, responsabilidad social empresarial, sostenibilidad, factor crítico de éxito y planeación estratégica -- Para la construcción del programa se realizaron investigaciones de tipo exploratorio y descriptivo, con el fin de obtener información se utilizaron distintas técnicas como entrevistas, documentos, observación y cuestionarios

Integration of Social Concerns in Collaborative Logistics and Transportation Networks

Part 21: Mobility and Logistics