Construction HydroPower

Tunnels and factor affecting the tunnelings

Tunnels are artificial underground passages constructed for various purposes like transportation, navigation, water supply, sewer, hydro-power, public utility, canals, etc.

In this article, we mainly discuss the point should consider while selecting the alignment of the tunnel. And also the necessary things such as Tunnel Drainage, Lighting Of Tunnels, Tunnel Ventilation and Lining In Tunnel respectively.

While selecting the alignment of the tunnel following points should be considered :

  • The route should as short as possible
  • The straight path is preferred
  • Easily accessible
  • Careful selection of entry and exit location

Factors affecting the tunneling

  • Land topography
  • Geological selection of the alignment
  • Hard rocks
  • Groundwater
  • Creep or tectonic movements

Factor need to consider while doing work of alignment of the tunnel

1. Tunnel Drainage

PRE DRAINAGE: A drainage arrangement before the construction of the tunnel is known as pre-drainage.

DE-WATERING: It is the drainage arrangement that is carried out during the construction time of the tunnel.

PERMANENT DRAINAGE: The methods of permanent drainages are:

  1. Provision of longitudinal pipelines
  2. Concrete lining
  3. Grouting with cement or chemicals

2. Lighting Of Tunnels

The lighting of the tunnel is a very important environmental factor to utilize the full efficiency of manpower or machine involved in work with proper safety.

The minimum requirements for lighting in tunnel are as follows:

  • Adequate lighting should be provided at each and every point
  • Lighting at the working face should be provided
  • Lamps should be fixed at both sides and center
  • Hauling equipment should have their own lighting system
  • Excavating equipment and other heavy equipment should have their own lighting system

3. Tunnel Ventilation

Ventilation is the process of replacing used air with fresh air. It is done by both artificial and natural methods.

Objectives of ventilation:

  • To replace the used air by fresh air
  • To remove harmful gases
  • Supply adequate amount of oxygen to workers
  • Remove the excessive amount of moisture present inside the tunnel.

4. Lining In Tunnel

Tunnel lining is a part of the support design provides inside the construction area of tunnels. Lining can be done by brick, timber, concrete, stone, rock reinforcement, steel, etc.

Objectives of lining in tunnel:

  • It withstand the soil pressure
  • It gives support to loose soil
  • Provides proper shape to the tunnel
  • It strengthen the weak portion
  • It makes the tunnel free from water penetration
  • To ensure streamline flow for water tunnels.

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Energy Crisis and its Solution in Nepal

After the massive earthquake of 2072B.s, we suffered from the blockage done by India. You may hear it for the common people: We’ve to reduce our dependence on foreign oil; bla bla. Fine. I’m not arguing. But how?

Have we got a lesson from the blockage or not? Are our policies change or not? Genuinely, we didn’t get a lesson. The consumption of non-renewable energy is increasing day by day. We say one thing and did one thing. We are best at that.

Even in factories, they are using diesel to generate electricity. Most hilly regions are still a mile away from accessing the electricity. Where the electricity is available, they are not getting continuous power supply. Even having the world’s second-largest water resources we are unable to produce a sufficient amount of energy for our daily livelihood.

We also have great potential for Solar Energy and wind energy but we don’t really do anything to utilize that. If we do that it was really negligible as compared to resources and necessity. We are unable to use our own available resources, so we suffered a lot from the energy crisis.

Here, in this article I will brief the short term and long term methods to overcome energy crisis.

Short term solution for energy crisis

  1. Leakage control: It was believed that around 20 to 25% of electrical energy is losses due to leakage so we can control the leakage for the short term solution.
  2. Use of Alternative energy: Wind energy, solar energy are alternative sources of energy. If the government decrease the taxes on solar panel and on battery required for solar people will get attracted toward the clean energy like solar energy. Also, in the Himalayan parts of Nepal, the velocity of air is suitable for the production of energy if government help and funded on turbine purchases and other instruments then the problem of energy crisis in remote areas will be solved.
  3. Review of energy Prices: Price is an important factor, that plays a vital role in the consumption of energy. If the price of electrical energy is cheap, obviously people will use more. So, the energy price should be review yearly and must be suitable so that poor class people can also consume.
  4. Cross border transmission: In Nepal, the production of electrical energy is high and consumption of it is low in the rainy season. For this we can implement a policy like cross border transmission in which when we produce more energy than required we supplied to another country and while we required we take electrical energy from others. This is also one of the short term measures to prevent an energy crisis. In-country like Nepal wherein the summer season the level of water is high so, the production of electricity is also hight. But in the winter season, the production of electricity decreases due to the water level on stream decrease so production is also low. I think this method is one of the best methods. so, that no electricity can get waste.
  5. Optimization of storage and PROP project:  If we increase the storage capacity the production capacity of electricity will be high and the same throughout the year.

Long term solution for the energy crisis

  1. Storage project: Storage project is long term solution from energy crisis because if we see in the country like Nepal where in summer season the level of water in stream is high so in summer season hydropower produce more amount of energy but in winter the flow of water will decrease and the water height is also decreased so to maintain the power production similar throughout the year storage based project should be given priority.
  2. Sustainable investment: To overcome the energy crisis problem in the country or in the Asian region we need to focus on sustainable investment. Sustainable projects should be chosen for investment and to get the maximum benefit from the investment.
  3. South-Asian Pool

List of hydropower projects in Nepal

  1. Kali Gandaki (144 MW)
  2. Kulekhani (92MW)
  3. Marshyandi (69 MW)
  4. Middle Marshyandi (70 MW)
  5. Khimti (70 MW)
  6. Bhotekoshi (36 MW)
  7. Chilime (22 MW)
  8. Jhimruk (12 MW)

Read this article: Understanding Energy Crisis in Nepal – Assessment of the Country’s Energy Demand and Supply in 2016

Also Read: Electricity Production, Transmission, Distribution in Modern Society.

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Electricity – Production, Transmission, and Distribution in Modern Society.

Electricity is the term of energy and with the development of civilization, necessity and importance of energy increased. Among different forms of energy, electricity is one of the basic and fundamental forms of energy that has been an invincible part of our modern society.

And now at the present time, electricity cannot be taken out separately from the list of our basic needs.

Is Electricity Is Our Basic Need?

There are lots of things to show off the importance of urban areas. But where we are living in rural areas might not visually find much usage of electricity. But there is. Whatever we find around us form toothbrush, toothpaste, shoes, books, food, clothes, furniture, etc. everything is the part of the industrialization of which electricity is the first priority.

Similarly, electricity has lots of importance in our daily life too. In the morning, to get up we set up an alarm on our mobile phone or portable watch.

If it is winter we use the heater and in summer, we need a fan to cool ourselves, and when the sun is about to set we need to light our home, and the gadgets like mobile phones, watch and laptops, all need electricity to run. In the absence of electricity, they will run out of battery. If we keep our step out of our home, the vehicles use electricity.

If we are in the office, we need electricity to use or a computer, photocopy machine, etc. And we move from village to city areas, when people get up they use an electric toothbrush, water heater to take shower, vacuum cleaner to clean their room and washing machines to wash their clothes, and so far from smallest to largest scale industries all need electricity to start and keep running.

As a conclusion, in today’s modern world, our life becomes inoperable without electricity and since it is the basic thing for other developments like communication, transportation, industrialization, education, health, etc. It is the fundamental infrastructure of development.

Source of electrical energy

Sources of energy are divided into two different parts from which electricity can be generated.

Thermal (Heat emitting) Thermal (Heat emitting)
Coal, Nuclear fission,          Solar, tidal
Geothermal (Heat of Earth)       Wind, Hydropower

Production of Electricity

Generally, electricity is generated by hydropower. In this system, the water of the river is collected in a dam in order to filter the water and give it potential so that it can be systematically used for the generation of electricity.

  • Water collected in a dam is then allowed to flow at high speed to the turbines.
  • The kinetic energy of the water makes the turbines rotate.
  • Then the mechanical energy is converted into electrical by generators connected to the turbines.
  • And the generated electrical power is collected in the national grid.
  • The national grid is the storehouse of the country’s hydropower energy.

Transmission of Electricity

Electricity Station

The hydropower energy stored in the National Grid is then transmitted by the high tension line. A high tension line carries a very high voltage of electrical energy. The three lines of high tension transmission are called Blue line, Yellow line, and Redline. Electricity cannot be used directly from a high tension line for the general-purpose since this contains a very high voltage of current.

Distribution of Electricity

Since electricity cannot be distributed high tension lines for normal purposes. Step-down transformers shall be in distribution areas to distribute the electricity for normal use. The step-down transformer converts high voltage current to lower potential thus used to convert high tension transmission to low voltage phase and neutral line and finally distributed for home and office use.

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