Project 1
1. Mention the need for a metro rail in a developing economy.
Considering India as a country with developing economy below mentioned points shows the importance of metro rails in India.
Metro rails are the most desirable infrastructures for the cities in India. They are known for facilitating people’s safe, quick, and easy movement. The transit system helps connect the hard-to-reach places with the rest of the city, which dissipates congestion as people reduce the usage of their vehicles. Moreover, with the inception of metro rail, the quality of life of people has also improved by providing more economic activities to the less influential segment of society. In this era of population explosion, the incoming of metro rail has proved to be a boon for society. With the pace with which Indian cities are getting populous, the Mass Rapid Transit Systems are the need of the hour.
The National Metro Rail Policy of 2017 has also advised the cities with a population of 20 lakhs or more to look for Mass rapid Transit Systems. Metro Rail is just one type of the MRTS, others being the:
Bus ways and bus rapid transit systems.
Light Rail Transit
Tramways
Regional Rail
India is investing heavily in the country’s transport infrastructure, imitating the Western Transportation System. The prospects of the metro rail are pretty bright in India. Cities are witnessing fast growth in the economic domain, and the clear manifestation is the increased number of personal vehicles. The negative side of the coin is that it has resulted in severe congestion and an increase in the pollution level of a country. The remedying efforts are required in the public transportation system, and the most pressing need is the implementation of the MRTS.
Metro rail has seen substantial growth in India in recent years, and the rate of growth is going to become twice or thrice in the coming years. The cities are facing the need for metro rail to meet daily mobility requirements. The metro rail encourages the walkable developmental pattern, which is also beneficial for society. The other merit of Metro rail is that it reduces cost and travelling time, which lowers the cost of production of goods and services, which significantly improves the city’s competitiveness. The pollution level has also reduced with the maximum public transport usage, bringing down chronic diseases and resulting in public health benefits.
Metro rails are needed because of the following reasons:
The most efficient transportation system is space occupancy, energy consumption, and numbers transported.
They are very high-capacity carriers, transporting many people during peak hours.
Unlike buses and other modes of public transportation, metro rails are eco-friendly, cause much less sound pollution, and have no air pollution.
They possess greater traffic capacity. It carries as much traffic as seven lanes of bus traffic and 24 lanes of car traffic.
It reduces the journey time from 50% to 75%.
The usage of metros should be promoted more and more as it helps in reducing the levels of greenhouse gases.
The number of road accidents has also gone down drastically as the people have chosen the Metro. Speeding usually happens when people are late for their work.
Metro provides air-conditioned travelling with the best comfort at relatively cheap rates.
Social Impact of the Metro Rail: All members of the society, irrespective of their caste, religion, financial status, can travel, which enhance the social integrity of the country. The necessity of a driving license is also eliminated to a great extent. It has come as a blessing in disguise for those who cannot drive or ride.
The economic impact of the Metro Rail: Mass Transit Development improves the usefulness and efficiency of the Public Transit system, which results in increased business for commercial developments and helps improve the country’s economy. Public Transit systems offer considerable savings in materials, labour, energy over other private transit systems. In addition, they have very efficient engines to carry large capacities, which helps in saving fuels.
4. For a prestressed U girder, calculate the following with the given data,
Area = 2.1735m2
I = 0.74035m4
Calculate Prestressing force considering 76.5% jacking stress with 72 no. of strands.
To convert a jacking stress percentage to Pascals (Pa), you need to know the reference stress and the percentage value. The conversion is straightforward:
Jacking Stress (Pa) = (Percentage Value / 100) * Reference Stress (Pa)
For example, let us consider reference stress of 200,000 Pascals (Pa), the jacking stress in Pascals would be:
Jacking Stress (Pa) = (76.5 / 100) * 200,000 Pa = 0.76.5 * 200,000 Pa = 153,000 Pa
So, a jacking stress of 76.5% would be equivalent to 153,000 Pascals.
P = f_j * A * n = 153000 x 2.1735 x 72 = 23943.27 KN
Calculate Section Modulus of U-girder considering ybot = 0.594m
Consider b = 4 m
S = (b x ybot ^ 2) / 6 = (4 x 0.594^2) / 6 = 0.235
Calculate eccentricity of Prestress tendons from CG of section considering ybot = 0.594m and cg of PT cables = 0.140m from soffit level.
e= ybot-ycg = 0.594 - 0.140 = 0.454
Calculate Stress at bottom of U-girder considering M=10628.58kN-m and details mentioned previously.
σ = (M * c) / I = (10628.58 x 0.594 ) / 0.74035 = 8527.55