Challenges in Design & Construction of Elevated Grade Separators with Wide Deck & Single Central Pier, in urban areas.

Author(s):  
Alok Bhowmick ◽  
Sanjay Jain

<p>India’s transport sector is large and diverse; it caters to the needs of 1.25 billion people. Roads are the dominant mode of transportation in India today. They carry almost 90 percent of the country’s passenger traffic and 65 percent of its freight. Cognizant of the need to create an adequate road network to cater to the increased traffic and movement of goods, Government of India has recently allotted Rs 640 billion (US$ 9.55 billion) to National Highway Authority of India (NHAI) for roads and highways and Rs 270 billion (US$ 4.03 billion) for rural roads under PMGSY scheme (as on 20th April 2017). One of the impediment in the fast progress of road infrastructure is acquisition of land &amp; related regulatory hurdles. Completion of as many as 112 projects of NHAI is delayed on account of such factors. There is a restriction of the available width and to spread the road horizontally. Therefore, present trend in urban areas is to go for elevated grade separators, wherein both surface level as well as elevated road can be fully utilised for traffic movement. By avoiding costly land acquisition, it results in reduction in cost of the project and certainly segregate local and fast moving traffic, thereby further increasing speed of movement. Design and Construction of such elevated corridors however poses many challenges to structural engineers. Restricted work space during construction adds to the challenge and brings out many innovative solutions to the problems. This paper discusses case studies of number of such projects for which the authors are presently associated in design and construction planning. These projects are in various stages of construction.</p>

2017 ◽  
Vol 19 (4) ◽  
pp. 614-640

The problem of reducing CO2 emissions from transport, a major contributor to the greenhouse effect, has become a growing concern for the scientific community and various international committees monitoring climate change. Energy savings in the transport sector are a key factor towards rational management of oil reserves, while new trends in the automotive market have already been established, supported by research on efficient and environmentally-friendly technologies and alternative fuels to face fossil fuel dependency. The road transport sector is an important part for most developed economies but also a major source of pollutant emissions. In this framework, this paper focuses on transport emissions along the main road axis in Greece, connecting the country’s two largest urban areas, during the years 2008-2014, a period of prolonged recession. Based on traffic data collected at the toll stations along the highway, greenhouse gas and pollutant emissions were calculated using the COPERT4 emission estimation tool. According to the results, a sharp fall in emissions is observed largely due to traffic volume reductions, but also due to a prevailing trend for larger displacement vehicles and technologically improved vehicles with better environmental standards.


Abstract. Our towns are increasingly protected by buildings and water paved pavements. Moreover, the city's climate is far from normal. Rainwater is not filtered underground due to the absence of the permeability of the common concrete pavement to water and air permeability. In addition, the exchange of heat and humidity with air is difficult for the soil, and it's not possible to change the temperature and relative humidity of the Earth's surface in urban areas. At the same time, the safety from both car and foot passenger traffic is limited by a plash on the road on a rainy day. Since the 1980s, work on permeable asphalt pavements has started in developed countries like the US and Japan. For roadway applications, permeable concrete is also widely used as a surface course in Europe and Japan Improving skid resistance and reducing noise from traffic. Only about 20 – 30 MPa can the material reach's compressive intensity. Due to their low strength, such materials cannot be used as pavement. Only frames, walking routes, parking garages, and park trails can be used with permeable concrete. Utilizing specified analyses, small materials, admixtures, organic intensifiers and changing the ratio, strength and abrasion resistance of the concrete mix, the porous concrete may be greatly enhanced.


2021 ◽  
Vol 2021 (24) ◽  
pp. 112-133
Author(s):  
Artur Onyshchenko ◽  
◽  
Mykola Garkusha ◽  
Mykola Klymenko ◽  
◽  
...  

Introduction. The use of modern materials in the road industry is increasingly common in the construction of roads, one of the modern materials is the use of polymer culverts. The analysis of application of plastic culverts on highways is carried out in the work. The general provisions of design and construction of hydraulic structures of transport construction in the form of culverts made of polymeric materials on highways are given. The existing hydraulic calculation, strength calculations of culverts made of polymeric materials on highways are given. Problem statements. From the literature analysis it is established that culverts made of polymeric materials on highways are in difficult operating conditions, which differ from the operating conditions of reinforced concrete and metal pipes. Purpose. Is to study the effectiveness of culverts made of polymeric materials. Results. The analysis of physical and mechanical properties of culverts made of polymeric materials on highways is carried out. Methods of calculation of culverts from polymeric materials on highways are given. As a result of the conducted researches the analysis of efficiency of application of culverts from polymeric materials on highways is executed. On the basis of the conducted researches the basic requirements to culverts from polymeric materials on highways are established. Conclusions. The results of the research were used in the development of a plan of experimental research to improve regulations for the design, construction and repair of culverts made of polymeric materials on highways. The use of polymer pipes will make it possible to make progressive technical solutions for drainage in road projects.


Energies ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 8146
Author(s):  
Heriberto Pérez-Acebo ◽  
Robert Ziolkowski ◽  
Hernán Gonzalo-Orden

Traffic calming measures (TCMs) are implemented in urban areas to reduce vehicles’ speed and, generally speaking, results are obtained. However, speed is still a problem in rural roads crossing small villages without a bypass and with short-length urban areas, since drivers do not normally reduce their speed for that short segment. Hence, various TCM can be installed. It is necessary to maintain a calm area in these short segments to improve road safety, especially for pedestrian aiming to cross the road, and to save combustible by avoiding a constant increase-decrease of speed. Four villages were selected to evaluate the efficiency of radar speed cameras and panels indicating vehicle’s speed. Results showed that the presence of radar speed cameras reduces the speed in the direction they can fine, but with a lower effect in the non-fining direction. Additionally, a positive effect was observed in the fining direction in other points, such as pedestrian crossings. Nevertheless, the effect does not last long and speed cameras may be considered as punctual measures. If the TCMs are placed far from the start of the village they are not respected. Hence, it is recommended to place them near the real start of the build-up area. Lastly, it was verified that longer urban areas make overall speed decrease. However, when drivers feel that they are arriving to the end of the urban area, due to the inexistence of buildings, they start speeding up.


Author(s):  
José van

Platformization affects the entire urban transport sector, effectively blurring the division between private and public transport modalities; existing public–private arrangements have started to shift as a result. This chapter analyzes and discusses the emergence of a platform ecology for urban transport, focusing on two central public values: the quality of urban transport and the organization of labor and workers’ rights. Using the prism of platform mechanisms, it analyzes how the sector of urban transport is changing societal organization in various urban areas across the world. Datafication has allowed numerous new actors to offer their bike-, car-, or ride-sharing services online; selection mechanisms help match old and new complementors with passengers. Similarly, new connective platforms are emerging, most prominently transport network companies such as Uber and Lyft that offer public and private transport options, as well as new platforms offering integrated transport services, often referred to as “mobility as a service.”


Author(s):  
Thierry Brenac

This paper deals with safety at horizontal curves on two-lane roads outside urban areas and the way the road design standards of different European countries account for this safety aspect. After a review of some research results, the main aspects of curve geometry and the curve's place in the horizontal alignment are analyzed. The main conclusions are that the traditional design speed approach is insufficient and that formal complementary rules in road design standards, especially to improve compatibility between successive elements of the alignment, must be introduced. If such complementary rules already exist in some national standards, they are neither frequent nor homogeneous throughout the different countries, and it seems that they are not based on sufficiently developed knowledge.


2020 ◽  
Vol 13 (1) ◽  
pp. 304
Author(s):  
Anna Pernestål ◽  
Albin Engholm ◽  
Marie Bemler ◽  
Gyözö Gidofalvi

Road freight transport is a key function of modern societies. At the same time, road freight transport accounts for significant emissions. Digitalization, including automation, digitized information, and artificial intelligence, provide opportunities to improve efficiency, reduce costs, and increase service levels in road freight transport. Digitalization may also radically change the business ecosystem in the sector. In this paper, the question, “How will digitalization change the road freight transport landscape?” is addressed by developing four exploratory future scenarios, using Sweden as a case study. The results are based on input from 52 experts. For each of the four scenarios, the impacts on the road freight transport sector are investigated, and opportunities and barriers to achieving a sustainable transportation system in each of the scenarios are discussed. In all scenarios, an increase in vehicle kilometers traveled is predicted, and in three of the four scenarios, significant increases in recycling and urban freight flows are predicted. The scenario development process highlighted how there are important uncertainties in the development of the society that will be highly important for the development of the digitized freight transport landscape. One example is the sustainability paradigm, which was identified as a strategic uncertainty.


2021 ◽  
Vol 12 (1) ◽  
pp. 18
Author(s):  
Lennart Adenaw ◽  
Markus Lienkamp

In order to electrify the transport sector, scores of charging stations are needed to incentivize people to buy electric vehicles. In urban areas with a high charging demand and little space, decision-makers are in need of planning tools that enable them to efficiently allocate financial and organizational resources to the promotion of electromobility. As with many other city planning tasks, simulations foster successful decision-making. This article presents a novel agent-based simulation framework for urban electromobility aimed at the analysis of charging station utilization and user behavior. The approach presented here employs a novel co-evolutionary learning model for adaptive charging behavior. The simulation framework is tested and verified by means of a case study conducted in the city of Munich. The case study shows that the presented approach realistically reproduces charging behavior and spatio-temporal charger utilization.


Electronics ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 193
Author(s):  
Mohamed Ben bezziane ◽  
Ahmed Korichi ◽  
Chaker Abdelaziz Kerrache ◽  
Mohamed el Amine Fekair

As a promising topic of research, Vehicular Cloud (VC) incorporates cloud computing and ad-hoc vehicular network (VANET). In VC, supplier vehicles provide their services to consumer vehicles in real-time. These services have a significant impact on the applications of internet access, storage and data. Due to the high-speed mobility of vehicles, users in consumer vehicles need a mechanism to discover services in their vicinity. Besides this, quality of service varies from one supplier vehicle to another; thus, consumer vehicles attempt to pick out the most appropriate services. In this paper, we propose a novel protocol named RSU-aided Cluster-based Vehicular Clouds protocol (RCVC), which constructs the VC using the Road Side Unit (RSU) directory and Cluster Head (CH) directory to make the resources of supplier vehicles more visible. While clusters of vehicles that move on the same road form a mobile cloud, the remaining vehicles form a different cloud on the road side unit. Furthermore, the consumption operation is achieved via the service selection method, which is managed by the CHs and RSUs based on a mathematical model to select the best services. Simulation results prove the effectiveness of our protocol in terms of service discovery and end-to-end delay, where we achieved service discovery and end-to-end delay of 3 × 10−3 s and 13 × 10−2 s, respectively. Moreover, we carried out an experimental comparison, revealing that the proposed method outperformed several states of the art protocols.


2021 ◽  
Vol 13 (8) ◽  
pp. 1417
Author(s):  
Jiguang Dai ◽  
Rongchen Ma ◽  
Litao Gong ◽  
Zimo Shen ◽  
Jialin Wu

Road extraction in rural areas is one of the most fundamental tasks in the practical application of remote sensing. In recent years, sample-driven methods have achieved state-of-the-art performance in road extraction tasks. However, sample-driven methods are prohibitively expensive and laborious, especially when dealing with rural roads with irregular curvature changes, narrow widths, and diverse materials. The template matching method can overcome these difficulties to some extent and achieve impressive road extraction results. This method also has the advantage of the vectorization of road extraction results, but the automation is limited. Straight line sequences can be substituted for curves, and the use of the color space can increase the recognition of roads and nonroads. A model-driven-to-sample-driven road extraction method for rural areas with a much higher degree of automation than existing template matching methods is proposed in this study. Without prior samples, on the basis of the geometric characteristics of narrow and long roads and using the advantages of straight lines instead of curved lines, the road center point extraction model is established through length constraints and gray mean contrast constraints of line sequences, and the extraction of some rural roads is completed through topological connection analysis. In addition, we take the extracted road center point and manual input data as local samples, use the improved line segment histogram to determine the local road direction, and use the panchromatic and hue, saturation, value (HSV) space interactive matching model as the matching measure to complete the road tracking extraction. Experimental results show that, for different types of data and scenarios on the premise, the accuracy and recall rate of the evaluation indicators reach more than 98%, and, compared with other methods, the automation of this algorithm has increased by more than 40%.


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