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ABSTRACT
In this project we have focused on problems of urban area traffic congestions and opted the underpass as best solution. Since traffic congestion is a severe problem in all existing metropolitan & upcoming metropolitan cities, traffic congestion results to delay in work, fuel wastage, diseases to humans, etc. The paper consists of case study, analysis and design of underpass at rotary junction near IGI airport Delhi. In this project we have designed an underpass using Finite Element Approach by BOX Method. This method is used where there the allowable soil pressure is low and their are chances of differential settlement. In this method we have analysed firstly without cushion and then with cushion.
We have done this project with three methods viz...
1) Manual/MS Excel method
2) Single Beam analysis
3) Finite Element Method
Firstly in Manual method we calculated Loads, then Moments with there Fixed End Moments then we analysed this by Moment distribution Method and then we design it.
In Single Beam analysis method we do by Staad (Beam method) while In Finite Element we have done by Staad.Pro (plate method). And we compare all the three results to get the best & economical solution of design of underpass.
INTRODUCTION
As we know that traffic congestion has been one of the major problems in India specially in metropolitan cities. In this era of rapid development where time is considered money, we cannot even dream of loosing hours in the traffic. Traffic congestion needs to tackled and eradicated from the daily life of people.
In order to cater the needs of people and provide them rapid and uninterrupted flow of traffic various underpasses and flyovers had been constructed in the past as well as are under construction at the various junctions of the road.Many people working in the Commercial centre’s which may have narrow streets.Shortage of off-street parking which means people park on the roads and so increase congestion. People not using public transport - either because it is less convenient, too expensive or not available.More people own and use cars.
(Traffic jam in shsnghai,china)
Traffic problems in urban cities
Cities are locations having a high level of accumulation and concentration of economic activities and are complex spatial structures that are supported by transport systems. The most important transport problems are often related to urban areas and take place when transport systems, for a variety of reasons, cannot satisfy the numerous requirements of urban mobility. Urban productivity is highly dependent on the efficiency of its transport system to move labor, consumers and freight between multiple origins and destinations. Additionally, important transport terminals such as ports, airports, and railyards are located within urban areas, contributing to a specific array of problems. Some problems are ancient, like congestion (which plagued cities such as Shanghai,New York,Mumbai etc), while others are new like urban freight distribution or environmental impacts. Among the most notable urban transport problems are:
i. Traffic congestion and parking problems. Congestion is one of the most prevalent transport problems in large urban agglomerations. It is particularly linked with motorization and the diffusion of the automobile, which has increased the demand for transport infrastructures. However, the supply of infrastructures has often not been able to keep up with the growth of mobility. Since vehicles spend the majority of the time parked, motorization has expanded the demand for parking space, which has created space consumption problems particularly in central areas. The spatial imprint of parked vehicles is significant.
ii. Public transport insufficiency. Many public transit systems, or parts of them, are either over or under used. During peak hours, crowdedness creates discomfort for users as the system copes with a temporary surge in demand. Low ridership makes many services financially unsustainable, particularly in suburban areas. In spite of significant subsidies and cross-financing almost every public transit systems cannot generate sufficient income to cover its operating and capital costs.
iii. Problems for pedestrians. These problems are either the outcome of intense traffic, where the mobility of pedestrians and vehicles is impaired, but also because of a blatant lack of consideration for pedestrians in the physical design of facilities.
iv. Loss of public properties. The majority of roads are publicly owned and free of access. Increased traffic has adverse impacts on public activities which once crowded the streets such as markets, agoras, parades and processions, games, and community interactions. These have gradually disappeared to be replaced by automobiles. In many cases, these activities have shifted to shopping malls while in other cases, they have been abandoned altogether. Traffic flows influence the life and interactions of residents and their usage of street space. More traffic impedes social interactions and street activities. People tend to walk and cycle less when traffic is high.
v. Environmental impacts and fuel consumption. Pollution, including noise, generated by circulation has become a serious impediment to the quality of life and even the health of urban populations. Further, fuel consumption by urban transportation has dramatically increased and so the dependency on petroleum.
vi. Accidents and safety. Growing traffic in urban areas is linked with a growing number of accidents and fatalities, especially in developing countries. Accidents account for a significant share of recurring delays. As traffic increases, people feel less safe to use the streets.
vii. Land consumption. The territorial imprint of transportation is significant, particularly for the automobile. Between 30 and 60% of a metropolitan area may be devoted to transportation, an outcome of the over-reliance on some forms of urban transportation. Yet, this land consumption also underlines the strategic importance of transportation in the economic and social welfare of cities.
viii. Freight distribution. Globalization and the materialization of the economy have resulted in growing quantities of freight moving within cities. As freight traffic commonly shares infrastructures with the circulation of passengers, the mobility of freight in urban areas has become increasingly problematic. City logistics strategies can be established to mitigate the variety of challenges faced by urban freight distribution.
Delhi is the worlds 5th worst city in terms of traffic Jams.There are 5.5 million approx registered vehicles in the city while NCR has 11.2 million approx.Delhi & NCR losses nearly 420 million man-hours every month while commuting between home and office due to traffic congestion.In 2005-06 IGI recorded a traffic of more than 20.44 million passengers(both Domestic & International).
Vehicular Growth in Delhi
(Traffic congestion on ring road in delhi)
Possible solutions for traffic congestion
Various solutions to these problems have been tried:-
i. Ring roads and by-passes
ii. Park and Ride.
iii. One way streets.
iv. Multi-storey car parking.
v. Banning cars from the main market area .Cars are banned from the centre of Milan (Italy) on Sundays.
vi. Charging car drivers when they enter the city centre.
vii. Improved technology would maximize the efficiency of automobiles, buses, and other modes of transportation and could play a key role in reducing emission increases.
viii. Building and maintaining sidewalks,
ix. Separating slow-moving traffic (bicycles and cycle rickshaws) from motorized traffic,
x. Enhancing the quality and range of mass transit services,
xi. Eliminating inefficient and very polluting two-stroke engines in scooters and motorcycles,
xii. Using cleaner low-carbon natural gas fuels,
xiii. Enhancing rapid transit,
xiv. Discouraging the use of private vehicles in densely populated areas by improving the public transport
xv. Flyovers & Underpasses.
ADVANTAGES OF UNDERPASSES
i. To provide uninterrupted traffic flow at major intersections in cities.
ii. To provide cattle crossing on highways,
iii. To provide smooth & uninterrupted traffic on national highways.
iv. For saving fuel by avoiding long routes with the help of underpass.
OUR MOTIVE
Through our project DESIGN OF UNDERPASS AS A BOX USING FINITE ELEMENT METHOD we are trying to give the best possible efficient and economical solution to overcome the above mentioned traffic congestion problems especially at road crossings with the help of an underpass structure.
METHODOLOGY
i. Generation of software using spread sheet.
ii. Design of underpass using single beam analysis.
iii. Design of underpass using Finite Element Approach.
iv. Comparison of results.
Finite Element Method
Finite element analysis uses a system of points that makes a mesh, programmed to include the material and the structural properties which identify the structural behaviour under precise loading conditions.The conditions at different points are analyzed to determine the structural behaviour.
Benefits Of Finite Element Method
i. Less expensive design cycle, increased productivity, and increased revenue,
ii. Calculate the correct combined behaviour of a structure and the ground,
iii. Predict the ground movement, structural deflections and loads with accuracy,
iv. Account for the interaction effects of adjacent structures.
Application of FEM in Structural Engineering
i. Finite Element Analysis provides a comprehensive indication of the distribution of stresses and a visualization of the bending or twisting of structures where a failure may occur.
ii. Predicting failure due to the development of stresses has become simpler, by an accurate indication of the affected location, thus allowing the designers to redesign accordingly.
Target Achieved:
i. Design of spread sheet,
ii. Analysis of forces acting on the underpass using single beam analysis,
Analysis of forces acting on the underpass using finite element approach