scholarly journals Influence of mounting joints of sections of a collapsible bridge on his stress-strain state

2020 ◽  
Vol 7 (2) ◽  
Author(s):  
Sergey Tomilov
Keyword(s):  
Carrying Capacity ◽  
Design Feature ◽  
Single Track ◽  
Technical Parameters ◽  
Emergency Situations ◽  
Operational Characteristics ◽  
Bridge Structures ◽  
Bridge Building ◽  
Double Track ◽  
The Military

Temporary bridges are necessary to ensure movement during the construction or repair (reconstruction) of capital bridge structures, operational communication of interrupted tracks in various emergency situations, for one-time or seasonal transport communications. For this purpose, reusable mobile prefabricated structures are advisable. Inventory sets of collapsible bridges were designed and manufactured primarily in the interests of the military department, but are currently widely in demand and are used in the civilian sector of bridge building because of their economy, mobility, and accessibility in transportation. Among others, including modern collapsible bridge designs, the middle automobile collapsible bridge (CAPM), developed in 1968 and modernized in 1982 for the needs of the USSR Ministry of Defense, occupies a special place. In the process of withdrawing the CAPM sets stored in storage to the civilian construction sector, a significant demand for these structures was found to be due to their following advantages: complete staffing with all elements of the bridge, including supports; the possibility of overlapping spans of 18.6, 25.6, 32.6 m with the dimensions of the driving bed 4.2 m for single-track and 7.2 m for double-track passage Passport carrying capacity is designated as 40 tons for single-track passage and 60 tons for double-track passage. Since, according to a number of geometric and technical parameters, CAPM designs do not fully comply with the requirements of modern standards for capital bridges, their application is mainly oriented as temporary. It should be noted that with minor refinement – the installation of modern fences and a double-track transverse arrangement of sections for single-lane traffic, it is possible to achieve compliance with the required geometric parameters of the driving bed and the total lifting capacity for bridges on public roads of IV and V of technical category. The article considers the design feature of the pin mounting joints of sections of a collapsible span as a factor determining the carrying capacity, the nature of general deformations and, as a result, affecting the transport and operational characteristics of the bridge structure. The purpose of this study is to analyze the operation of the pin mounting joints of the sections of the spans of the CAPM with the assessment of the stress state of the elements of the connection node. We consider the novelty in the consideration of the issue to be an assessment of the strength of the elements of the pin joints and its effect on the general deformations – the deflections of the main beams.

Value of psychotherapeutic self-control in energy saving at experts of dangerous professions

2018 ◽  
pp. 56-65
Author(s):  
Е.Ю. Соколов ◽  
А.И. Адаев ◽  
А.А. Фомин ◽  
Л.Г. Магурдумова
Keyword(s):  
Energy Saving ◽  
Military Personnel ◽  
The State ◽  
Self Control ◽  
Preliminary Training ◽  
Control Methods ◽  
State Of Health ◽  
Emergency Situations ◽  
The Military ◽  
Business Trip

In article the importance of use of psychotherapeutic actions of self-control by employees of a dangerous profession is stated during the work in emergency situations. The state of health of fighters who before the direction in business trip were trained previously in self-control methods at different stages of performance of a fighting task, with a condition of group of the military personnel who didn’t pass preliminary training in energy saving methods is compared.

scholarly journals Establishing changes in the technical parameters of nipple rubber for milking machines and their impact on operational characteristics

2020 ◽  
Vol 2 (1 (104)) ◽  
pp. 78-87
Author(s):  
Andriy Paliy ◽  
Alexander Nanka ◽  
Mykhailo Marchenko ◽  
Vadym Bredykhin ◽  
Anatoliy Paliy ◽  
...  
Keyword(s):  
Technical Parameters ◽  
Operational Characteristics

scholarly journals Особенности деформаций главных балок железобетонных пролетных строений автодорожных мостов при их усилении внешней арматурой

2020 ◽  
Vol 44 (3) ◽  
pp. 151-158
Author(s):  
S. Tomilov
Keyword(s):  
Carrying Capacity ◽  
Load Capacity ◽  
Reinforced Concrete Beams ◽  
Main Beam ◽  
Relative Deformation ◽  
Operational Parameters ◽  
The Road ◽  
External Reinforcement ◽  
Bridge Structures ◽  
High Degree

Так как в настоящее время в эксплуатации находится достаточно много автодорожных мостов, запроектированных и построенных в различные периоды, их, как и всю дорожную сеть, необходимо поддерживать в состоянии, соответствующем нормативам, а для этого проводить ремонт с использованием элементов усиления несущих конструкций. При качественном возведении и надлежащем уходе высокая степень сохранности мостов позволяет продлить срок их службы путем решения ряда конструктивных вопросов, наиболее актуальным из которых считают обеспечение нормативной грузоподъемности. Усиление с целью повышения грузоподъемности эксплуатируемых мостов достигается путем добавления элементов внешних или внедренных в состав существующего конструктива в зависимости от типа сооружения, его состояния и доступной технологии производства. Однако не только грузоподъемность, но и подверженность конструкций деформациям определяет транспортно-эксплуатационные параметры сооружения, характеризующие послеремонтное состояния моста. Цель настоящего исследования – анализ известного и широко востребованного способа усиления железобетонных балок внешним армированием как обеспечивающего минимальное вмешательство в существующие основные конструкции, технологичного и доступного в исполнении. Впервые дана оценка влияния стадийности включения в работу элементов усиления на общие деформации – прогибы главных балок. Ключевые слова: главная балка, грузоподъемность, усиление, внешняя арматура, свободная затяжка, стадийность работы, относительная деформация, прогиб. Currently, there are quite a lot of road bridges in operation, designed and built in different periods. It is necessary to maintain the road network including bridge structures in a condition that meets up-to-date standards, and for this repair should be carried out using reinforcing elements of the supporting structures. With high-quality construction and proper maintenance, a high degree of safety of bridges allows to extend their service life by solving a number of design issues, the most important of which is considered to be the provision of standard load capacity. Strengthening in order to increase the carrying capacity of operated bridges is achieved by adding elements external or incorporated into the existing structure, depending on the type of structure, its condition and available production technology. However, not only the carrying capacity, but also the susceptibility of structures to deformations determines the transport and operational parameters of the structure, which characterize the post-repair state of the bridge. The purpose of this study is to analyze the well-known and widely demanded method of reinforcing reinforced concrete beams with external reinforcement as providing minimal interference with the existing basic structures, technological and affordable in execution. For the first time, an assessment of the influence of the staging of the inclusion of reinforcement elements in the work on the general deformations – deflections of the main beams. Keywords: main beam, carrying capacity, reinforcement, external reinforcement, free rod, staging of work, relative deformation, deflection.

scholarly journals Operational criteria in the justification of electrification of railway lines

2018 ◽  
Vol 180 ◽  
pp. 06005
Author(s):  
Andrzej Massel
Keyword(s):  
Rolling Stock ◽  
The Political ◽  
Economic Factors ◽  
Single Track ◽  
Railway Network ◽  
Railway Line ◽  
Passenger Traffic ◽  
Post War ◽  
Operational Criteria ◽  
Double Track

The process of electrification of the Polish railways took place from 1936 till early 1990s. Despite the political constraints of the post-war times, the decisions on electrification of particular sections of the railway network were usually based on economic factors. In 1970s and 1980s so called electrification thresholds were used to justify the need for electrification of railway line in question. They took into the number of tracks (single-track lines, double-track lines), terrain conditions (flat terrain, upland terrain) and the traffic structure (the share of passenger traffic) into account. In the framework of National Railway Program till 2023 (KPK) the realization of electrification projects have been undertaken again. The present paper deals with importance of the operational criteria in the decision-making concerning justification of electrification of railway lines. These criteria include the shortening of the journey times on particular sections, shortening of stops on the stations with the change of the type of traction, the savings of train operating companies resulting from the traction unification (change of demand for rolling stock and for workshops for its servicing), improvement of reliability and punctuality of services.

Improving Railway Operational Efficiency with Moving Blocks, Train Fleeting, and Alternative Single-Track Configurations

2020 ◽  
Vol 2674 (2) ◽  
pp. 146-157 ◽  
Author(s):  
Adrian Diaz de Rivera ◽  
C. Tyler Dick ◽  
Leonel E. Evans
Keyword(s):  
Heterogeneous Traffic ◽  
Capital Investments ◽  
Single Track ◽  
Delay Performance ◽  
Train Control ◽  
Schedule Flexibility ◽  
Financial Consequences ◽  
Operating Strategies ◽  
Traffic Composition ◽  
Double Track

With installation of positive train control (PTC) on many U.S. rail corridors, Class I railroads may soon leverage these investments in communications network infrastructure to implement “advanced PTC” systems incorporating moving blocks. Train control with moving blocks can benefit operating strategies that dispatch fleets of multiple trains running at minimum headways. On single-track corridors with passing sidings long enough to hold multiple trains, fleeting may increase the efficiency of train meets, reduce train delay, and yield incremental capacity benefits. Alternative single-track configurations with fleet-length sidings at double the spacing of conventional single-train sidings can facilitate these operating strategies while minimizing additional track infrastructure and associated capital and maintenance costs. To investigate the operational synergies between moving blocks, fleeting, and longer but less frequent sidings, Rail Traffic Controller software is used to simulate and compare the delay performance of train operations on representative rail corridors for different combinations of fleeting strategy, train control system, siding configuration, and freight traffic composition. Operating fleets in conjunction with moving blocks produces the lowest overall train delay in specific cases of low schedule flexibility and heterogeneous traffic. With more efficient meets, moving blocks and/or fleeting primarily benefit low priority trains that typically wait for opposing traffic during train meets. Such incremental line capacity benefits have short-term financial consequences as they allow additional capital investments in double track to be deferred. Knowledge of train delay performance under moving blocks and fleeting will aid railway practitioners evaluating investments in advanced PTC systems and track infrastructure expansion.

Evaluation of Load Carrying Capacity of the Perforated Shear Connector with Flange Heads

2006 ◽  
Vol 326-328 ◽  
pp. 1811-1816 ◽  
Author(s):  
Young Ho Kim ◽  
Jae Ho Jung ◽  
Soon Jong Yoon ◽  
Won Sup Jang
Keyword(s):  
Carrying Capacity ◽  
Load Transfer ◽  
Shear Capacity ◽  
Load Carrying Capacity ◽  
Shear Connector ◽  
Shear Connectors ◽  
Load Carrying ◽  
Bridge Structures ◽  
Composite Bridge ◽  
New Type

In the construction of composite bridge structures, various types of shear connectors are usually used to provide an efficient load transfer and the composite action of two or more different materials. In the previous work conducted by authors, a new type of the shear connector was introduced, which is the perforated shear connector with flange heads (T-shaped perforated shear connector), and the structural behavior of the shear connector was discussed based on the results of push-out tests. For the practical design of new shear connector, it is necessary to develop the equation for the prediction of the load carrying capacity of the shear connector. In this study, the existing design equations for the Perfobond shear connector were briefly analyzed and the equation for the prediction of the shear capacity of T-shaped perforated shear connector was suggested empirically. By comparing the results obtained by the suggested equation, the existing equations for the Perfobond shear connector, and the experiment, the applicability and effectiveness of the suggested equation was estimated.

Writing Culture Doctrine: Public Anthropology, Military Policy, and World Making

2010 ◽  
Vol 8 (4) ◽  
pp. 1087-1093 ◽  
Author(s):  
Robert Albro
Keyword(s):  
Point Of View ◽  
Military Policy ◽  
Policy Makers ◽  
Academic Scholarship ◽  
Public Anthropology ◽  
Writing Culture ◽  
Policy And Planning ◽  
Bridge Building ◽  
The Military ◽  
Policy Communities

I concur with Michael Mosser that bridge-building between academic and military policy communities should be an important priority. I also agree that this is a challenging task. But my sense of why this is both important and challenging differs from Mosser's in some key respects. Despite qualifications along the way, Mosser's account suggests that academia has a particular responsibility to make itself legible and available to military policy makers, but not the other way around. As he explains, his topic grew from a project concerned about “whether the academy is asking militarily interesting questions.” And he proceeds by thinking about how academic scholarship might be “more tightly integrated” with the doings of military policy and planning. Undertaking bridge-building by firstly asking how the US academy can be more effectively leveraged to support national security goals sets up a largely one-sided and unilateral engagement, where the burden is primarily on academia to explain itself to the military policy community, and probably to do so within a frame of reference sensible to the policy crowd but not necessarily vice-versa. This sets up, in short, a scenario making it less likely for policy makers to listen to what academics might be saying, particularly whenever this appears to complicate established agendas. From my point of view, the best mutual outcomes flow from a more balanced dialogue. This includes policy makers taking academic frames at least as seriously when talking with them, so that greater clarity can be reached about how, and under what circumstances, scholarship might contribute to policy concerns, but also when academic contributions might be inappropriate, irrelevant, or even impossible.

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