ARYA INSTITUTE OF ENGINEERING TECHNOLOGY

AND MANAGEMENTCHHABRA THERMAL POWER PLANT

ASH DYKE CONSTRUCTION

SUBMITTED TO SUBMITTED BY Civil Engineering Department

Chandra Mohan Lodha 4th Year Student

CONTENTS

1. Introduction2. Ash Dyke 3. Machinery Used In Construction 4. Materials Used In Ash Pond Construction5. Preparation Of Base6. Construction Process7. Drainage System Of Dyke8. Use Of Dyke 9. Special Features10. Conclusion

INTRODUCTION

Chhabra Thermal Power Plant is one of Rajasthan coal fired power plant. It is located at Chowki Motipura (Village) of tehsil Chhabra in Rajasthan Baran district. The planned capacity of power plant is 2650MW at the end of 12th Five year plan.The first and 2nd unit at Chhabra super thermal power plant was set up at a cost of Rs2,350 crore. Chhabra is all set to become a power generation hub in the state as in the second phase two more units with a capacity of 250 MW each will be installed. Rajasthan Rajya Vidyut Utpadan Nigam Limited (RVUN) has been entrusted with the job of development of power projects under state sector, in the state along with operation & maintenance of state owned power stations. Government of Rajasthan constituted the Rajasthan Rajya Vidyut Utpadan Nigam Ltd. (RVUN) under Companies Act-1956 on 19th July, 2000. The Nigam is since playing lead role in giving highest priority to the power generation for manifold and rapid development of the state.The generating Stations of RVUN have acquired a distinctive reputation in the country for their efficient and economic power generation. Chhabra Thermal Power Station is a 1000-megawatt (MW) coal-fired power station in Rajasthan state, India.A 1320 MW expansion of the power station is under construction.

The power station is owned and operated by Rajasthan Rajya Vidyut Utpadhan Nigam (RVUN or RRVUN), a government-owned utility. It began as a 500 MW power station, commissioned in 2009-2010. The power station was later expanded by two 250 MW units (Units 3&4). Unit 3 was commissioned in 2013, and unit 4 in 2014.

ISTALLED CAPACITY

Unit 1 - 250 MW - Operating (commissioned October 30, 2009)Unit 2 - 250 MW - Operating (commissioned May 4, 2010)Unit 3 - 250 MW - Operating (commissioned September 14, 2013)Unit 4 - 250 MW - Operating (commissioned 30 June 2014)Unit 5 - 660 MW - ConstructionUnit 6 - 660 MW - Construction

Ash Dyke/pondAn ash pond is an engineered structure for the disposal of bottom ash and fly ash. The wet disposal of ash into ash ponds is the most common ash disposal method , but other methods include dry disposal in landfills. Dry-handled ash is often recycled into useful building materials. Wet disposal has been preferred due to economic reasons, but increasing environmental concerns regarding leachate from ponds has decreased the popularity of wet disposal. The wet method consists of constructing a large "pond" and filling it with fly ash slurry, allowing the water to drain and evaporate from the fly ash over time. Ash ponds are generally formed using a ring embankment to enclose the disposal site. The embankments are designed using similar design parameters as embankment dams, including zoned construction with clay cores. The design process is primarily focused on handling seepage and ensuring slope stability.

Machinery Used In Construction

Machinery used in ash pond construction like

• Poke Land • Jcb • Dozer• Grader• Roller• Trucks

Poke Land :- Poke land is a hydraulic machine which used in the digging. It is used in the larger project work and speedily constructional work . It have higher load bearing capacity.The poke land machine is also available in two types 1.Three hundred poke land 2. Two hundred poke land Both the machines have different capacity according to the design capacity .

JCB :- jcb is a earth moving machine which used in the construction work . It give more importance in the construction filed . It is multi used machine in the construction work .it is provide faster work .

DOZER :- It is a earth cutting machine which used in the larger project work . Mostly it is used in the depth of earth about 20m for the harder stone cutting/collection of stone particles.It have front larger size part which is very used and have higher capacity.

GRADER :-A grader, also commonly referred to as a road grader, a blade, a maintainer, or a motor grader, is a construction machine with a long blade used to create a flat surface during the grading process. second blade that is placed in front of the front axle. Some construction personnel refer to the entire machine as "the blade". Capacities range from a blade width of 2.50 to 7.30 m and engines from 93–373 kW(125–500 hp).

ROLLER :-A road roller (sometimes called a roller-compactor, or just roller) is a compactor type engineering vehicle used to compact soil, gravel, concrete, or asphalt in the construction of roads and foundations, similar rollers are used also at landfills or in agriculture.In some parts of the world, road rollers are still known colloquially as steam rollers, regardless of their method of propulsion. This typically only applies to the largest examples (used for road-making).

Trucks :-Normally trucks are used for the transportation but in the construction field it is used for sand , soil, stone, cement etc material dumping/supply. From one place to another place. Modern trucks are largely powered by diesel engines, although small to medium size trucks with gasoline engines.

Material Used In Ash Pond Construction

For the ash pond construction many materials required .Some materials are :-Concrete (M7.5, M25)Bricks (Fly Ash )Cement Soil LDPE ( 150&270 micron thick geomembrane )Black cotton ( Black Sand 300mm )

Preparation Of Base

The preparation of base for the ash pond construction is simplest process. Firstly survey of the all area and test of field like soil test , ground water level of area .marked the area required for the ash pond construction . After that dig the depth about 12meter depth all area by machinery used . Finished the base surface clearly with 0 degree angles. The ash pond all sides having width 12 to 15 meter for vehicle travelling and transportation . The ash pond all walls having slope 60 degree. Cutting the all walls with 60 degree slope and finish properly . Around the ash pond drainage system must required so drainage base also cut by machines.Now base is complete for the ash pond design process.

Construction Process Of Ash Dyke

The Construction of ash dyke required special skills and engineering knowledge . The Construction of ash dyke in the parts like 1. Construction of trench beam 2. Construction of base3. Construction of sloping walls4. Construction of bad

1. Construction Of Trench Beam :- The design of trench beam according to the drawing all the measurements used according to the drawing. The trench beam located nearly the sloping wall base point. The beam having size 500mm height , 230 mm width (500*230)mm and concrete M7.5 used in the construction.

2. Construction Of Base :- After cut and finishing the surface 150mm depth soil fill in the all base area and then soil covered by175 micron thick LDPE spread in all the area . And then LDPE jointed by the electric jointing machine.

STEP -3CONSTRUCTION OF BASE

STEP -1 STEP -2

3.Construction Of Sloping Walls:- The design of sloping walls of ash dyke required technical specifications . Design according to the given drawing .The concrete used in the wall construction is M25.Construction of sloping walls are as follows given dimensions.Length 9m , width 3m , thickness 75mm.

4. Construction Of Bad :- the construction of ash dyke bad is similar process as like dams bad process. The width of bad is equal to 15metere with flat surface. It is also used for transportation in the construction time .It is made up of sand with compaction , compaction should be completed by the vibration roller. The length of bad is depends upon the size of dyke.

Construction Of Drainage System

The drainage system of ash dyke is outer side of the dyke. With special supervision and according to the given drawing.The drainage system base completed by using of concrete M7.5 and walls having dimensions height 800mm , width 350mm and length depends upon the drain length.The slope between starting point of wall and end point of wall is 1:0.5The drain walls constructed by the cement , sand , bricks with proper ratio of cement sand and water.

PRIMARILY, THE FLY ASH IS DISPOSED OFF USING EITHER DRY OR WET DISPOSAL SCHEME. IN DRY DISPOSAL, THE FLY ASH IS TRANSPORTED BY TRUCK, CHUTE OR CONVEYOR AT THE SITE AND DISPOSED OFF BY CONSTRUCTING A DRY EMBANKMENT (DYKE). IN WET DISPOSAL, THE FLY ASH IS TRANSPORTED AS SLURRY THROUGH PIPE AND DISPOSED OFF IN IMPOUNDMENT CALLED "ASH POND".

Use of Ash Dyke

Special Features• Use Of LDPE (175 micron thick membrane) to protect under ground water. • Use of trench beam to maintain black cotton (Black Soil).• Use of sloping walls with concrete to protect seepage of water.• Use of proper drainage system around the ash dyke.

CONCLUSION

The construction of ash dyke for the fly ash disposal and utilization in the thermal power plants is compulsory.But in the ctpp power plant ash dyke construction is something different as compare to other ash dykes.Comparison clarify by the special features of the dyke.The engineering summer internship time is very good for my practical knowledge of the field.

THANK YOU