Impact of Tunnels in Environment

Abstract: The one of main aim of my research works are going on to save or

protect the environment from different risky or poisonous gases, chemicals

and other damaging things. Different construction materials (both renewable &

non-renewable) which are used at constructing any structure, building, road,

tunnel, bridge etc. But all Engineers have to know the idea of sustainable

expansion and the particular request of construction in its related areas

without causing the green environment. To satisfy the needs, huge rush,

demands, time saving etc., of publics in roadways, Traffic flow or Road

Tunnels are constructed. In this searching the rank of ventilation in

construction of Tunnels is find out because different harmful or poisonous

gases or chemicals are produced by the vehicles transient through it. The aim

of this part of this searching is to bring the consciousness about the tunnel

environment whereas constructing Tunnels and to reduce the risky damage

inside the tunnel and also to the environment location

One of a definition or Keywords: Tunnels, Determinations of tunnelling, Road

or Traffic Tunnels, defence of environment, harmful or deadly gases, Tunnel

Ventilation.

INTRODUCTION

Everything around us are called environment. The surrounding

circumstances, impacts, or forces that effect or modify as:

1- The whole complex of climatic, edaphic and biotic factors that act upon an

organism or an ecological system and ultimately determine its form and

survival.

2- The aggregate of social and cultural conditions as customs, laws,

language, religion, economic and political organization that influence the life of

an individual or community.

Tunnel construction afflictive Environment usually Engineer would uncaring a

set of values and references that he have to comply with and threshold the

values that must not be surpassed. His practical keys would be established

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keeping in attention that the inevitable productions as noise irritation, waste or

effluents do not hamper or affect the living and working conditions inside and

outside the process that he is designing or operating.

But, environment would also uncaring that he must pay consideration on

protection the Natural resources by using and try best way to huge amount as

much as possible of the renewable energy sources and recycled materials,

and struggle to reach a lifelong expansion which mostly focuses the “Green &

Sustainable Environment”.

OBJECTIVE

The objective of this part of this searching to focus on the tunnels, the

ventilation of which straight concerns the environmental problems. Ventilation

is exactly designed as well as worked to make or deliver a user responsive

atmosphere inside the tunnel i.e. safe, clean, healthy and pleasant for

everyone who use it and make sure that the surround dings of the tunnel

should not be ignored and the environmental circumstances nearby the tunnel

entries have to preserve. This is mainly experiential in city sites. Furthermore,

controlling the release of contaminants through chimneys or use openings in

the ceiling is also very an important subject.

In This part it will covers the bas introduction of the following:

A- Tunnel

Any of The horizontal or can be curve underground passageway open at both

the ends to the ground surface is known as “Tunnel”.

Tunnel of the construction mostly takes place under the town, cities, rivers,

canal and through mountains by the removal of overload, creation cuts and

then laying roof slabs. There are mainly three different types of tunnels.

They are:

1. Traffic or Road Tunnels

2. Hydro-Power Tunnels

3. Public Utility Tunnels

In that searching try get fully deals with the “Traffic or Road tunnels” and its

proper ventilation from any damaging or dangerous outcome.

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B- Main reason of tunnelling:

There are many purposes of tunnelling. For example

1) They are excavated across the hills and highlands, cutting hole to make

new roads or new railways

2) Tunnels decrease the distance crossways natural difficulties like hills or

mountains and sea which save the time and also offer suitability

3) Compression tunnels which help water to pass with force and produce

power.

4) For supply of drinking water public utility tunnels are drawn

c. Traffic or Road Tunnels:

Tunnel can sort out many problems but also it come out with new problems worried include, for example

A. it makes Air pollution with regular health risks,

B. Absence of escape lanes which constitutes a severe risk for people who

have to stop their cars,

D. Fire hazards and subsequent smoke progress which could be a real threat

C. It could be a real threat because fair hazards and smoke progress

E. it cause higher accident. Reason for that it Reduced visibility higher

Environment, Health, and Safety

The process of placing concrete in situ was incompatible with timber supports.

In consequence, the first uses of concrete were for tunnels in good rock and it

was only with the introduction of steel supports that the use of concrete

became the norm for a tunnel lining material. An early use of concrete in

tunnel lining was for the “East Boston Tunnel of 1892”

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DIFFERENT SOURCES OF POLLUTION

Traffic is certainly one of the significant bases of environmental and air

pollution.

Which it does not only have a damaging influence on health but also in

different way affect the quality of life by troubling the eco-system, damage our

natural beauty in the world , national tradition, and many more. In spite of of

all the efforts and all kinds of recommendations to decrease, particularly in

large capitals cities , both traffic flow and one of its first irritations, i.e. the

pollutant emissions, in future soon, which may be predictable for the next few

decades that traffic will continue an significant source of pollution.

For that reason there are many planes and lot of money has been spent in

connecting the monitoring equipment, developing data broadcast networks

and building direction centres.

The burning of fuels in vehicles like petrol, LPG, CNG, petrol, diesel etc., and

engines produces a lot of toxic matters which direct or indirect affects the

environment a lot in every way. Depending on their attention,

Chemical stability and their adverse damage on environment and human

being, there are many exhaust gases which related development in use

tunnels for example

CO2: This is one the main product of the burning of a fossil fuel. This is

directly responsible for the “greenhouse effect” but is indirectly responsible for

health damage, when through a tunnel

SO2: it is one of gas which is production during use a tunnel especially in the

in the busy traffic

CO: also it one of them (gasses) which it is produced in a reducing

atmosphere.

There a lot of gasses more which only in this search give name (NO2, N2O,

NO, O3, CHO, OH,)

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VENTILATION

Passing or through a fresh air into any closed area like rooms, tunnels etc.

That process for providing a enjoyable atmosphere inside is known as

“Ventilation”.

Types of ventilation

1) Natural ventilation,

2) Untrue (not natural) ventilation.

Tunnel ventilation: it is being provided in the tunnels for providing enjoyable

air inside is known as Tunnel ventilation.

That systems (Tunnel ventilation) can be separated into three basic

ventilation arrangements,

1) Longitudinal,

2) Transverse and

3) Semi-transverse ventilation.

Longitudinal ventilation in Tunnels: The natural plan by acting in such a method that the mean air flow velocity

has a sufficient value which is the principle of the longitudinal ventilation,

For this purpose

One or more jet-fans close to the walls or the ceiling are connected that

provide the required driving force.

That system especially suitable for one way traffic, i.e. the air is blown

in the same direction in which the traffic goes.

With regard to pollutant concentrations, their maximum values are to

be expected at the tunnel exit, or, if several sections are present, at the

end of each section. The growing rate of course is a function of the

amount of emitted pollutants which, for a constant traffic flow it may be

assumed to be approximately constant.

Transverse ventilation in Tunnels:

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this principle as well as outlet air is ducted along the tunnel.

For this purpose:

It is blown into the tunnel through more or less similarly spaced

openings (slots) beside one of the walls.

All air is sucked off which through by the opposite wall also through

similarly spaced openings and let into a collecting channel.

In this method the air will flow perpendicular to the alliance of the tun

traffic and also to the tunnel

This method mainly suitable for all types long tunnels.

Semi-transverse ventilation in Tunnels:

This system is considered as the mixture of both the transverse and

longitudinal ventilation system.

The fresh air is supplied through openings in the walls or the ceiling,

and the vitiated air flows along the tunnel and leaves it through one of

the gateways according to the joint action of the pressure difference

between them and the piston outcome.

Would create a longitudinal velocity module If there is not driving force

available, the flow in the tunnel would be zero in the central and

maximum at both the portals.

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