CIVILSTAGRAM: 2015

Monday, 21 December 2015

Concrete Slump Test

slump test is a method used to determine the consistency of concrete. The consistency, or stiffness, indicates how much water has been used in the mix. The stiffness of the concrete mix should be matched to the requirements for the finished product quality Concrete Slump Test.
The concrete slump test is used for the measurement of a property of fresh concrete. The test is an empirical test that measures the workability of fresh concrete. More specifically, it measures consistency between batches. The test is popular due to the simplicity of apparatus used and simple procedure.

Procedure To conduct the Slump Test as follows:-

1) To obtain a representative sample, take samples from two or more regular intervals throughout the discharge of the mixer or truck. DO NOT take samples at the beginning or the end of the discharge.

2)Dampen inside of cone and place it on a smooth, moist, non-absorbent, level surface large enough to accommodate both the slumped concrete and the slump cone. Stand or, foot pieces throughout the test procedure to hold the cone firmly in place.

3)Fill cone 1/3 full by volume and rod 25 times with 5/8-inchdiameter x 24-inch-long hemispherical tip steel tamping rod. (This is a specification requirement which will produce nonstandard results unless followed exactly.) Distribute rodding evenly over the entire cross section of the sample

4)Fill cone 2/3 full by volume. Rod this layer 25 times with rod penetrating into, but not through first layer. Distribute rodding evenly over the entire cross section of the layer.

5)Fill cone to overflowing. Rod this layer 25 times with rod penetrating into but not through, second layer. Distribute rodding evenly over the entire cross section of this layer

6)Remove the excess concrete from the top of the cone, using tamping rod as a screed. Clean overflow from base of cone.

7Immediately lift cone vertically with slow, even motion. Do not jar the concrete or tilt the cone during this process. Invert the withdrawn cone, and place next to, but not touching the slumped concrete. (Perform in 5-10 seconds with no lateral or torsional motion)

8)Lay a straight edge across the top of the slump cone. Measure the amount of slump in inches from the bottom of the straight edge to the top of the slumped concrete at a point over the original center of the base. The slump operation shall be completed in a maximum elapsed time of 2 1/2 minutes. Discard concrete. DO NOT use in any other tests.

Types of Slump:-

1)Collapse Slump:-
In a collapse slump the concrete collapses completely. A collapse slump will generally mean that the mix is too wet or that it is a high workability mix, for which slump test is not appropriate.

2)Shear Slump:-
In a shear slump the top portion of the concrete shears off and slips sideways.
If a shear or collapse slump is achieved, a fresh sample should be taken and the test is repeated.
If the shear slump persists, as may the case with harsh mixes, this is an indication of lack of cohesion of the mix.

3) True Slump:-
In a true slump the concrete simply subsides, keeping more or less to shape
This is the only slump which is used in various tests.Mixes of stiff consistence have a Zero slump, so that in the rather dry range no variation can be detected between mixes of different workiability.

DAMPNESS IN BUILDING

Dampness in building

Dampness in building is one of the important aspects to consider during building design. Because if neglected, it will affect the building structure adversely and will create unhygienic condition for the persons living in that building.
*3 PRIMARY CAUSES OF DAMPNESS IN BUILDING:-
Penetration of water into the building components (such as walls, floors, roof or basement etc) is the primary cause of dampness.
The three primary causes of dampness in building are
Poor quality of construction material
Bad design
Faulty construction or bad workmanship
1. POOR QUALITY OF CONSTRUCTION MATERIAL
Most of the construction materials such as concrete, brick or plaster possess interconnected void within them. When these materials come in contact with water, water finds a path to penetrate into these voids. Again this water when aided by capillary action; moves in different direction causing dampness.
2. BAD DESIGN
At the time of designing a building, it is very important to consider what can be the source of water that can penetrate through building and accordingly the designer must mention where to provide what kind of damp proof course.
3. FAULTY CONSTRUCTION OR BAD WORKMANSHIP
Suppose a designer has specified that the thickness of damp-proof-course must be 15 mm. but due to lack of adequate supervision, the thickness of completed damp proof course become 10 mm. then this will not serve the purpose for which it is constructed and consequently it will lead to dampness in building.
6 MAJOR SOURCES OF DAMPNESS
When water comes in contact with building components such as walls, roofs, floor etc these components acts as a medium to help water to migrate into the building.
The 5 major sources of dampness are as follow.
1. Due to capillary action, the water present in ground soil may rise above the ground level through the walls. If ground water table is nearer to the building foundation then also it can also become a source of dampness.
2. Condensation of atmospheric moisture can also be a source of dampness. Because this form of water gets deposited on different components and gradually find their way to penetrate into the building causing dampness.
3. Rain water falling on external walls, parapets also causes dampness.
4. Rain water can also penetrate through the roofs if the roof is of bad quality. Inadequate roof slopes or defective junction between roof slab and parapet wall may cause dampness
5. Presence of gutter near the building will store the rain water and subsequently this water will create dampness in the external walls.
6. Wet areas of buildings (such as kitchens, bath rooms) having sub standard plumbing fitting can also be a source of dampness.
5 COMMON DEFECTS CAUSED BY DAMPNESS
The common defects caused by dampness in building are as follow.
1. Dampness causes efflorescence of bricks, tiles of stones.
2. It makes the plaster weak.
3. It may cause bleaching and flaking of paint due to formation of colored patches.
4. It causes corrosion of metals.
5. It promotes growth of termites.

Construction tips to Build A House

No one wants to pay more than necessary when building a home. But only the experts know how to save money on construction,
right? Not necessarily. Here are 15 tips that may help keep your building budget within reason, without compromising on the home
you want.
1. Buy a large lot with a friend or family member that can be split into two smaller lots. Some of the most appealing properties may be much larger than what you want or
can afford, yet the seller may not be willing to break up a large parcel. So if you can share the cost with someone else (preferably someone you don't mind having as a neighbor), you may be able to pick up a great building site for a reasonable price.
2. Consider a so-called problem lot — a hillside, narrow, or in-fill property. Generally,these types of lots are not as desirable as others, so they don't sell as quickly and
often go for a much lower price. With the right plan and a capable contractor, however, a potentially difficult lot might be perfect for
your new home.
3. Choose a canal or bay lot instead of ocean or lakefront property if you must have a waterfront site. These choices are usually less expensive but still water accessible. Plus, they provide great protection against
inclement weather.
4. Buy low-maintenance building materials — vinyl siding and metal roofing, for example.
Even if they are somewhat more expensive at installation, they will pay for themselves in the long run as you won't have to repair,
replace, or repaint.
5. Collect salvaged materials from demolition sites. Old barnwood, used bricks, and distinctive wood doors add inexpensive character to a home without exorbitant cost.
Many times you can have the materials at no cost, as long as you're willing to haul them
away. Just be sure to check first with the owner of the building being demolished.
6. Splurge only on those things you truly cannot live without. However, don't skimp on structural components or doors and windows
— for the safety and security of your home , you'll want to purchase the best you can afford in these areas.
7. Don't overbuild for the neighborhood. Ahome that is better and bigger than any other in its area will not command a fair price at resale. Instead, the assessment will
be colored by the lower-priced homes around it.
8. Monitor construction allowances as the home is being built to ensure you're getting what you asked for (and are paying for). This includes decorative details as well as structural elements. If you and your builder agreed, for instance, that a particular brand of insulation would be installed, don't accept
a lesser brand — at least not without a cost adjustment.
9. Use only a certified general contractor. The experience of a well-qualified contractor is invaluable to the home-building process.
In addition, seasoned professional have established relationships with suppliers and subcontractors — something you cannot possibly hope to get without years of
experience in the business.
10. Try to avoid site preparation charges — hauling in-fill dirt, grading, clearing trees, blasting rock. These processes are expensive
and add time to the building schedule right off the bat. Choose the best site you can afford and then pick a plan that fits that site or can be modified to better suit the site.
11. Avoid change orders — the changes in materials or blueprints that invariably occur in the midst of the building process. Not only
do change orders cost more money, they add considerable time and frustration to the building process. Decide exactly what you want before ground is broken — and then
stick to it.
12. Keep the depth of your home at 32 feet or less. Any more than that and roof trusses may need to be specially designed, which can add significant dollars to the overall
building cost. If you have sufficient land and want a larger house consider adding width or additional stories.
13. If you really want ceramic tile or
hardwood flooring but feel you can't afford it right now, consider vinyl flooring. Vinyl makes a good underlayment, and the tile or
wood can be installed right on top of it at a later date.
14. Choose a stock plan over custom-drawn plans. The savings in total cost are great and you can probably customize the stock plan to get exactly what you want.
15. Do you really need a three-car garage? If you only have two vehicles and you're counting on the extra bay for storage space,
consider other areas of the home that will work just as well — attic space, space under a stairwell, or spare bedroom. Or put up a
garden shed , which is cheaper than building a huge garage.

Vastu tips and Advices

Vastu Tips And Advices
its not ALWAYS necessary that you should follow the vastu,BUT the following information is for
all to know about the directions/placing and a little of vastu.
1) vastu means ” the ART of house or designing of house"
2)Generally the DIRECTIONS ARE FOUR.
· North, South, East and West.
· In India – major followers of vastu are present.
3) Vastu and fengshui both are related to ancient history, which deals with human, nature
and harmony of both.
4) In vastu the 8 directions are considered, they are NORTH,
SOUTH, EAST, WEST, NORTH- EAST, NORTH-WEST, and SOUTH-EAST AND SOUTH WEST.
5)the placing of the house, entrance,rooms,kitchen,toilets and bedrooms are based on the 5 natural elements, namely, WATER,AIR,EARTH,FIRE and SPACE.
6)These five elements are the MAJOR contributors for vastu and fengshui.
7) IN VASTU, The master bedroom should be placed at SOUTH – WEST corner.
8)Toilet / wash room / rest room/ bath room location to be at North – west corner.
9) KITCHEN location to be at SOUTH – EAST Corner.
10)Home / Building Entrance must be at NORTH – EAST Location.
11)By looking at the direction of Sun or compass, at particular location of Plot / land / site / home / office etc. the rooms are placed and need to be adjusted.
12) It depends on an individual to follow or NOT to follow the above tips.
13) Depending on the location, country, geography, sun directions, wind flows and environment all around the home or building placings can be done to suit the tranquillity of one and all.

SPECIAL VASTU – REQUIREMENTS AND TIPS FOR STAIRCASES:::
1)THE DIRECTION OF SAIRCASE STEP WHILE CLIMBING SHOULD BE TOWARDS – North
to South and East to West.
2) The Steps – of the Staircase must be always in ODD number as per vastu experts.
3)If the staircase – steps are found BROKEN, IMMEDIATELY THEY HAVE TO BE REPLACED
OR RECTIFIED.
4)The location of the staircase should be place generally at SOUTH or WEST SIDE OF THE
HOUSE / PLOT / BUILDING.
5) STAIRCASES MUST BE PAINTED IN LIGHT COLOURS; DARKER COLOURS SHOULD BE AVOIDED FOR STAIRCASES.
6) THE SPACE BELOW THE STAIRCASES MUST BE USED FOR STORAGE PURPOSE, as per
the advice of the vastu experts, the pooja room must not be placed below the staircases.
7)The circular design staircases are NOT good, as per vastu experts advice.
8)Generally the doors are kept at the entrance and at the exit of the staircases.
9) Turning of the staircases should be always to the clock wise direction.
10)The North – East Direction is considered as very auspicious and profitable place, so the staircase should not be located in THIS place, the staircase is not a profitable object, if it is placed in North – east corner.
11)If it is placed in north – east location, it would cause the damage to both health and wealth of the house owners and property owners.
12)The height of each step should be less than six inches and can be kept between 4 to 6 inches,
for the comfort and easy access.

Basic Requirements Of a Building

The planning and construction of a building should be aimed at fulfilling the following requirements:
1. Strength and stability
2. Dimensional stability
3. Resistance to dampness
4. Resistance to fire
5. Heat insulation
6. Sound insulation
7. Protection against termite attack
8. Durability
9. Security against burglary
10. Lighting and ventilation
11. Comforts and convenience
12. Economy.
1. Strength and Stability: Building should be capable of transferring the expected loads in its life period safely to the ground. Design
of various structural components like slabs, beams, walls, columns and footing should ensure safety. None of the structural components should buckle, overturn and collapse.
2. Dimensional Stability: Excessive
deformation of structural components give a sense of
instability and result into crack in walls, flooring etc. All structural components, should be so designed that deflections do not exceed the permissible values specified
in the codes.
3. Resistance to Dampness: Dampness in a building is a great nuisance and it may reduce the
life of the building. Great care should be taken in planning and in the construction of the building to
avoid dampness.
4. Resistance to Fire: Regarding achieving resistance to fire, the basic requirements laid
down in the codes are:
(a) the structure should not ignite easily.
(b) building orientation should be such that spread of fire is slow.
(c) In case of fire, there should be means of easy access to vacate building quickly.
5. Heat Insulation: A building should be so oriented and designed that it
insulates interior from heat.
6. Sound Insulation: Buildings should be planned against outdoor and indoor noises.
7. Protection from Termite: Buildings should be protected from termites.
8. Durability: Each and every component of the building should be durable.
9. Security against Burglary: This is the basic need the owner of the building expects.
10. Lighting and Ventilation: For healthy and happy living natural light and ventilations are
required. Diffused light and good cross ventilation should be available inside the building.
11. Comforts and Conveniences: Various units in the building should be properly grouped and integrated keeping in mind the comfort and
convenience of the user.
12. Economy: Economy without sacrificing comfort, convenience and durability is another basic
requirement of the building.

Basics of Surveying

Basics of Surveying
1)Definitions Surveying – the art of measuring distance and angles on or near the surface of the earth
Plane surveying – the land surface is considered to be a plane for all X
and Y dimensions, and all Z dimensions (height) are referenced to this plane. Most engineering surveys are plane surveys, those that cover long distances may need to correct for the earth’s curvature.
2)Equipment notebook – record all your data and sketches transit – used to establish straight lines and measure horizontal and vertical angles tape – measures distances
level rod – measures distances in
elevation
total station – electronic measuring
instrument that records and
processes field data.
prism rod – locates the points of
interest and reflect laser back to
total station for angle
and distance measurements.
engineer’s tape – measures the
height of the instrument (transit or
total station)
survey nails – locate points of
interest for future use
two-way radios – keeps contact
between the instrument person and
the rod person
2.1)Notebook
One of the most important aspects of surveying is taking accurate, neat,
legible, and complete field notes. The degree of completeness comes from practice.
Details thatseem obvious in the field may be obscure back in the office a couple weeks later.
Sketches of your surveyed area will
also aid in comprehension and
ordering of the data.
These sketches do not need to be to
scale. Do not crowd your notes.
At a minimum, ALWAYS record the
instrument height, rod height,
occupying point,
backsight point, and datapoint
ranges in your notebook. Then, if
there was an error in
inputting the correct data into your
total station, you have a double
check. A description
and sketch of each surveyed point
are very useful as well.
2.2)Level Transit
we can determine the elevation
difference between
Points 1 and 2 as such:
Reading on Level Rod 1 from
horizontal line of sight = 2.63 ft
Reading on Level Rod 2 from
horizontal line of sight = 7.21 ft
Elevation Difference = 4.58 ft
The distance between the points can
be determined with a measuring
tape.
If elevation at the instrument is
known:
Actual Elevation at Point 2 = Elev at
instrument + HI + LR1 Reading –
LR2 Reading
If elevation at Point 1 (backsight) is
known:
Actual Elevation at Point 2 = Elev at
Pt 1 + LR1 Reading – LR2 Reading
2.3 Total Stations
A total station records and processes
all the data collected in the field. It
measures
distances and angles by use of a
laser shot from the instrument and
reflecting prism on
the survey rod. A total station is
simply a computer. It can only know
what you input.
When you orient the total station
with a 3-D location and an angle at
each setup, it will
reference all ensuing point data to
that.
2.3) Location
If there is a benchmark available
that has known XYZ coordinates,
then great, use that as
a setup or backsight point. Most sites that EWB work in will not have
benchmarks. You have two other options, and the choice depends on the level of detail needed in your
survey. If precise detail is needed,
bring an accurate GPS system with
you to locate your position. If relative detail is needed,
then enter any value for your
location and reference
everything to that point, i.e. label
your northing as 5000, easting as
10,000, and elevation
as 1000. If the precise coordinates
are not necessary, this latter option
may be easier to
perform in the field.
*)Angle
Just giving your total station a
location lets it know where it is, but
it doesn’t know where
it’s looking. So, you will have to
orient the instrument as well. The
options for doing
this again depend on the level of
precision needed for the project. For
accuracy and
precision, you can either bring a
compass that tells you which
direction is true north, or
you can shoot a second point that
has known XYZ coordinates. Again,
this latter one will
be very rare in most EWB locations.
If you bring a compass, then station
your prism rod
in the direction of true north and
shoot with the total station. The
instrument will then
know where it is and where it is
looking.
If precision is not necessary, you can make an educated guess as the
direction of north
(without the aid of a compass) and
shoot the prism rod. This will at least
orient your
instrument and the rest of your
points will be referenced to this
location and direction.
2.4) Leveling
For each setup, the survey
instrument must be level. The
locations and orientation
established above assume a level
instrument. The basic procedure for
tripod and
instrument leveling is provided
below:
1. Center tripod over desired point
at an appropriate height and make
the base fairly level
2. Attach the instrument to the base
screw (Note: Do not let go of
instrument until the bottom screw
has been attached)
3. Turn on the instrument if using a
total station
4. Turn on the laser level or attach
plumb
5. Maneuver the tripod to center the
plumb on the control point
6. Coarse-level the instrument by
adjust the tripod legs individually
until the level
bubble is mostly centered (Note: this
adjustment will only minimally
adjust the location of the plumb)
7. To fine-tune the leveling, orient
the three black fine-tune level knobs
(at base of instrument) as a triangle
with a point facing away from you
a. Adjusting the two closest to you at the same time, turning them both
inward will move the bubble to the
left. Turning them both outwards
will move the bubble to the right.
b. Adjusting the knob away from
you, turning it counter-clockwise will
move the bubble away from you.
Turning it clockwise will move it
towards you.
8. After instrument is level, check
location of plumb. If you are within
a couple of inches, you may move the instrument by half-unscrewing the bottom screw and sliding the
instrument into place. If you are too
far off, then you will have to move
the whole tripod into position.
9. Repeat until the instrument is
level and over the correct point.
2.5) Viewscope Orientation
If you are using a total station,
sometimes it may not be obvious as
which way is up for
the survey gun. The correct
orientation has the horizontal fine-
tune knob on the lower
right and the vertical fine-tune knob
on the upper left as you are sighting
through the
instrument. Running the instrument
upside-down will invalidate your
data.
2.6)Moving the Instrument
When you shoot a point to use as
your next location, place a nail or
some other relatively stable marker in the ground. Move the instrument to the new nail. When setting up the
total station, tell the instrument which point you are on. Since you
have already shot this
point, it knows its location. Backsight to another control point, and the instrument will
now be correctly oriented and ready
to continue on. Be sure to check your error after the backsight. If it is large, there might have been a mistake in some previous measurement that you’ll need to double check.
3) Point Descriptions Be consistent with point descriptions. Label all your control points the same, i.e. do not label them as “control1”, “control2”, etc. Label them all as “control” (or some variation thereof) and let the point ID number
be the differentiating factor between
them.
The importance of these distinctions will become apparent if you are using a CAD program afterwards to draw up your survey points, since each point descriptions will become its own layer in the program.

Things Site Engineers must Know

Minimum thickness of slab is 125mm.
Water absorption should not be more than 15 %.
Dimension tolerance for cubes + or– 2 mm.
Compressive strength of Bricks is 3.5 N /mm
Maximum Free fall of concrete allowed is1.50 m.
In soil filling as per IS code for every 100sqm 3 sample for core cutting test should betaken.
Electrical conduits shall not run in column Earth work excavation for basement above 3m should be stepped formAny back filling shall be compacted 95% of dry density at the optimum moisture content
and in layers not more than 200mm for filling above structure and 300 mm for no structure F soling is specified the soling stones shall
be laid at 45° to 60° inclination (and not vertical) with interstices filled with sand or moorum.
A set of cube tests shall be carried out for each 30 cum of concrete / each levels of casting / each batch
of cement.
Water cement ratio for different grades of concrete shall not exceed 0.45 for M20 and above and 0.50 For M10 / M15 contractor For concrete grades M20 and above
approved admixture shall be used as per mix design requirements.
Cement shall be stored in dry places on a raised platform about 200mm above floor level and 300mm away from walls. Bags to be stacked not more than 10 bags high in
such a manner that it is adequately
protected from moisture and contamination.
Samples from fresh concrete shall be taken and at least a set of 6 cubes of 150mm shall be prepared and cured. 3 Cubes each at 7 days and 28 days shall be tested for compressive strength. The
test results should be submitted to engineer for approval.
If results are unsatisfactory necessary action/rectification/remedial measures has to be exercised.
Water used for both mixing and curing shall be clean and free from injurious amounts of oils, acids, alkalies, salts, sugar and organic
materials or other substances that may be deleterious to concrete or steel. The ph shall be generally between 6 and 8.
Cement shall be tested for its setting.
1. The initial setting time shall not be less than 30 minutes.
2. The final setting time shall not be more than 10 hours.
Slump IS 456
Lightly reinforced 25 – 75 mm
Heavily reinforced 75 – 100 mm
Trench fill (insitu & Tremie) 100 – 150 mm
(For Tremie no need of vibrator)
Curing Days Required
Super Sulphate cement : 7 days
Ordinary Portland cement OPC : 10 days
Minerals and Admixture added cement : 14 days
Cube Samples
1 – 5 M : 1 No.
6 – 15 M : 2 No’s
16 – 30 M : 3 No’s
31 – 50 M : 4 No’s
Above 50 M : 4 + 1 No of addition sample for each 50 M .

Wednesday, 2 December 2015

COMPRESSION TESTING MACHINE

Compression Strength:-
It means the maximum compressive stress that under gradually applied load a given solid material will sustain without fracture.

Compression tests:-
Well these are used to determine how a product or material reacts when it is compressed, squashed, crushed or flattened by measuring fundamental parameters that determine the specimen behaviour under a compressive load. These include the elastic limit, which for "Hooke's" materials is approximately equal to the proportional limit, and also known as yield point or yield strength, Young's Modulus (these, although mostly associated with tensile testing, may have compressive analogs) and compressive strength.

Procedure to Conduct test as follows:-

1)Preparation : Check all the things you need are ready. Check concrete compression machine is in working order.

2)Safety : Wear hand gloves and safety goggles.

3)Taking measurement : Take the measurement of concrete specimens (which are sent to laboratory for testing). Calculate the cross sectional area (unit should be on mm2) and put down on paper. Do the same for each specimen.

4)Start machine : Turn on the machine. Place one concrete specimen in the centre of loading area.

5)Lowering piston : Lower the piston against the top of concrete specimen by pushing the lever. Don't apply load just now. Just place the piston on top of concrete specimen so that it's touching that.

6)Applying load: Now the piston is on top of specimen. It is the time to apply load. Pull the lever into holding position. Start the compression test by Pressing the zero button on the display board.

7)Increasing pressure : By turning pressure increasing valve counter-clockwise, adjust the pressure on piston so that it matches concrete compression strength value. Apply the load gradually without shock.

8)Test is complete : Observe the concrete specimen. When it begins to break stop applying load.

9)recording : Record the ultimate load on paper displaying on machine's display screen.

10)Clean the machine: When the piston is back into its position, clean the creaked concrete from the machine.

11)Turning off machine: Match your record once again with the result on display screen. The result should still be on display screen. And then turn off the machine.

12)Calculate concrete compressive strength : The result we got from testing machine is the ultimate load to break the concrete specimen.

*)The load unit is generally in lb. We have to convert it in newton (N). Our purpose is, to know the concrete compressive strength.
*)We know, compressive strength is equal to ultimate load divided by cross sectional area of concrete specimen. We took the concrete specimen's measurement before starting the testing and calculated cross sectional area.
*)Now we got the ultimate load. So we can now calculate the concrete compressive strength.

Compressive strength = Ultimate load (N) / cross sectional area (mm2).
The unit of compressive strength will be N/mm2.

Saturday, 15 August 2015

LARGEST HYDROELECTRIC DAM

Hydroelectric dam that spans the Yangtze River by the town of Sandouping, located in Yiling
District, Yichang, Hubei province, China. The Three Gorges Dam is the world’s largest power station in terms of installed capacity (22,500 MW) but is second to Itaipu Dam with regard to the generation of electricity annually.

General Quick Facts:
Type: Concrete Gravity Dam
Cost: Official cost $25bn - actual cost believed to be much higher
Work began: 1993
Due for completion: 2009
Power generation: 26 turbines on left and right sides of dam. Six underground turbines planned for
2010
Power output: 49 billion kilowatt-
hours
Reservoir: 660km long, submerging 632 sq km of land. When fully
flooded, water will be 175m above sea level
Navigation: Two-way lock system became operational in 2004. One- step ship elevator due to open in 2009.
Land submerged: 13 cities, 140 towns, 1352 villages, 657 factories & 30,000 hectares of cultivated land
Relocation of People: 1.3 million to
located in 3 stages in 1997, 2003 &2009 Stretching
Construction:
Excavation: 102.6 million cubic meters of earth and stone (134 million cubic yards).
Concrete: 27.2 million cubic meters (35.5 million cubic yards).
Steel reinforcing bars: 354,000 tons.
Dam height: 185 meters (607 feet).
Dam length : 2,309 meters (1.4 miles) divided into three parts. In the center will be a 484-meter spillway section with 23 bottom outlets and 22 sluice gates. On the left and right of the spillway will be two giant power stations.

Rain Water Harvesting System.

What is Rain Water harvesting?

Rain Water Harvesting is an act of accumulating and storing rainwater for reuse. As we know rainwater is the purest form of water, we can utilize this water for various purposes after necessary purification process as per required. This system can be a boon in regions where there is shortage of water. This problem is common in today’s big cities. Hence rainwater harvesting can be very effective in these areas.
Broadly rainwater can be harvested for two purposes:
1. Storing rainwater for ready use in
containers above or below ground.
2. Charged into the soil for withdrawal later (groundwater recharging).
Importance of Rain Water harvesting Technique These techniques can serve the following
purposes:
1)Provide drinking water
2)Provide irrigation water
3)Groundwater recharge
4)Reduce storm water discharges, urban flood.
5)overloading of sewage treatment plants
6)Reduce seawater ingress in coastal areas.

*Rain Water harvesting Methods*
Rainwater harvesting can be harvested using different methods. It may follow surface harvesting methods or rain water collection methods which are explained below:
Rooftops:
In this method, rooftops are used for collecting the water. If buildings with impervious roofs are already in place, the catchment area is effectively available free of charge and they provide a supply at the point of consumption. Paved and unpaved areas i.e., landscapes, open fields, parks, storm water drains, roads and pavements and other open areas can be effectively used to harvest the runoff. The main advantage in using ground as collecting surface is that water can be collected from a larger area. This is particularly advantageous in areas of lo rainfall.
Water-bodies:
The potential of lakes, tanks and ponds to store rainwater is immense. The harvested rainwater can not only be used to meet water requirements of the city, it also recharges groundwater aquifers.
Storm-water drains: Most of the r colonies have proper network of storm water drains. If maintained neatly, these offer a simple and cost effective means for harvesting rainwater.

*Whether to store rainwater or use it for recharge?
The decision whether to store or recharge water depends on the rainfall pattern and the potential
to do so, in a particular region. The sub-surface geology also plays an important role in making this decision.
For example,
Delhi, Rajasthan and Gujarat where
the total annual rainfall occurs during 3 or 4 months, are examples of places wheregroundwater recharge is usually practiced. In places like Kerala, Mizoram, Tamil Nadu and Bangalore where rain falls throughout the year barring a few dry periods, one can depend on a small sized tank for storing rainwater, since the period between two spells of rain is short.
Wherever sub-strata is impermeable recharging will not be feasible. Hence, it would be ideal to
opt for storage. In places where the groundwater is saline or not of potable standards, the alternate
system could be that of storing rainwater. Beyond generalisations, it is the requirement that governs the choice of water harvesting technique
.
For example,
in Ahemadabad, which has limited
number of rainy days as that of Delhi, traditional rainwater harvesting tanks, known as tankas, are used to store rainwater even today in residential areas, temples and hotels.
How much rainwater can be harvested? The total amount of water that is received in the form of rainfall over an area is called the rainwater endowment of the area. Out of this, the amount that can be effectively harvested is called the water harvesting potential.
Water harvesting potential =
Rainfall (mm) xCollection efficiency.

Friday, 30 January 2015

STATIONS AND YARDS

Stations and Yards

Railway Station:-

“ It is the selected place on a railway line, where trains halt for one or more of the following purposes”

*Exchange of passengers

*For exchange of goods

*For overtaking

*For detaching engines and staff

Classification of Railway Stations:

Operational Classification

i) Block Stations

ii) Non Block Stations

iii) Special Class Stations

Functional Classification

i) Non- Junction or way side stations

ii) Junction Station

iii) Terminal Station

Site Selection for Railway Station:-
For selecting the site for railway stations following factors should be considered.

1)Adequate land
2)Level area with good drainage
3)Alignment
4)Easy accessibility
5)Water supply arrangement

Station Yard:-
A system of tracks laid usually on a level within defined limits,
for receiving,
For storing,
For making up new trains
For dispatch of vehicles
For other purposes over which movements are not authorized by a time table

Layouts of station yards:-
1)Halt
2)Flag Station
3)Crossing Stations
4)Junction Stations
5)Terminal Stations

Types of Yards:-
1)Passenger bogie Yards
2)Goods yards
3)Marshalling Yards
4)Locomotipassengers

Passenger Bogie Yard :
Passenger Bogie Yard Provides facilities for the safe movement of passengers and vehicles for the use of passengers.

Goods Yard:
Goods Yard Provides facilities for receiving, loading and un loading, delivery of goods and the movement of goods vehicles.

Marshalling Yard :
Marshalling Yard Is one where trains and other loads are received, sorted out and new trains are formed and dispatched onwards to their destinations.