Transmission tower

I was Visited a Site of Bajaj Engineers Project. We have seen their many problems arise in pile foundation and we think how this Problem Should Be Solved?
We Have Visited This Site And Decided To Do Project To Solve This Problem. Our Problem is pile foundation. According To Our Survey This Problem should be reduced by taking such steps towards this problem. We Make Survey On Whole Site And Find Out Problems And We Should Work On To Find Out Solution To Solve Problems

1. WELCOME

2. Project Transmission Line Foundation

3. Guided By:- HADIYA KIRAN

4. Transmission Line Tower Transmission towers are the most visible component of the power transmission system. Their function is to keep the high-voltage conductors (power lines) separated from their surroundings and from each other. A variety of tower designs exist that generally employ an open lattice work or a monopole, but generally they are very tall (a 500 kv tower might be 150 feet tall with cross arms as much as 100 feet wide), metal structures.

5. Where A= Tolani F.G. Polytechnic B= Site Visit

6. Map

7. Transmission Line Detail Transmission Line

8. Types Of Transmission Tower :- Suspension Towers Terminal Tower Tension Tower Transposition Tower

9. There are special type of Tower as per Special Usage River Crossing Tower Railway/Highway Crossing Tower Also according to angle of Deviation there are few types of Transmission towers :- A Type Tower angle of deviation 0-2 B Type Tower angle of deviation2-15 C Type Tower angle of deviation 15-30 D type Tower angle of deviation 30-60

10. Suspension Tower In this case, the tower is supposed to carry a downward force, and a lateral force, but not a longitudinal force. These may have, for each conductor, an insulator string hanging down from the tower. Two strings making a "V" shape.

11. Tension Tower A dead-end tower (also anchor tower , anchor pylon ) is a fully self-supporting structure used in construction of overhead transmission lines. A dead-end tower uses horizontal strain insulators and is used when the circuit changes to a buried cable, or at a substation as a transition to a "slack span" entering the equipment. Dead-end towers may be used when a transmission line changes direction by more than a few degrees.

12. Transposition Tower In electrical power transmission, a transposition tower is a transmission tower that changes the relative physical positions of the conductors of a transmission line. A transposition tower allows these sections to be connected together, while maintaining adequate clearance for the conductors.

13. Types Of Foundation Used In Transmission Tower:- Steel Foundation Concrete Spread Footing Caisson Pile Foundation Rock Foundation Raft Foundation Novel Foundation

14. Suitability of F oundation According to Transmission Tower:- Steel Foundation:- There are pyramid arrangements that transfer the horizontal shear to the base through truss action. Other types transfer the shear through shear members that engage the lateral resistance of the compacted backfill.

15. Suitability Of Steel Foundation:- This type of grillage foundation can also be safely used for light towers where the soil encountered is soft and is permanently water-logged.

16. Rock Foundations :- If bed rock is close to the surface, a rock foundation can be installed. It is also helpful to wet the hole before placing concrete to ensure a good bond.

17. Piles Foundation Are Use:- Piles are used to transmit loads through soft soil layers to stiffer soils or rock. The piles can be of wood, prestressed concrete, cast in place concrete, concrete filled shells, steel H piles, steel pipes filled with concrete, and prestressed concrete cylinder piles.

18. Suitability Of Raft Foundation:- This type of foundation is suitable where the ground conditions are very poor and bearing power of the soil is so low that individual spread footing cannot be provided.

19. Suitability of Caisson:- Caisson is suitable when hard strata are available at shallow depth and soil bearing capacity is very high.

20. Site Details Project Cost:- 16 cr. Pile Depth:- 20 m Pile Dia:- 600 mm Reinforcement Detail:- Bars:- Longitudinal bar 8 Nos-25 mm Dia. Pitch:- 150 mm Stirrups:- 8 mm Concrete Grade:- M-30 Cement Grade:- Cement 53 Grade OPC Steel Grade:- Fe 415 Spacing Of Tower:- 350 meter Total No of Pile:- 312 Total Length of Project :- 15 km. ‘ Adani Port’ to ‘Tuna Port’

21. Problems Break Down Because of Mechanical Failure Transport Of Heavy Machine Hard strata Boring Blade Trimie got chock up Because Of Various Reasons . Delay in Setting time of concrete while piling Welding/Joint Failure At Lapping

22. Problems Hollow piling problem Collapse of sides of pile during drilling/boring of pile Due to entrapped air in trimie pipe, there is a risk of blockage in it.

23. Solutions And Preventive Measure Hard Strata Problem:- Solution:- A range of high strength drilling equipment including rock augers, rock roller bits, core barrels and cluster hammers to give a productive solution to drilling in rock from 5 MPa to over 300 MPa . With the support of a large fleet of rotary drill rigs we can take on small or large projects for any diameter of drilling in high strength rock. Cluster drills have been used to drill rock sockets up to 8 m long in very high strength basalt

24. Boring Blade:- Preventive Measure:- If the bore hole in such bigger that a person can insert in the drilled hole and by rope the bit/blade can be took out. Broken of bit:- The piece of that has fallen into the bore hole can be taken out by the magnet. Solution:- Boring plate should be used of good quality (carbon Steel ) Carbon tools should be welded on boring blades. Rock augers are generally the preferred tool for drilling in materials that have a high concentration of cobbles or boulders.

25. Collapse of sides of pile during drilling/boring of pile:- Preventive Measure:- The liner should be placed up to a certain Depth or up to the depth of the loose soil strata. Solution:- Normally the following three major mineral groups of soil are used instead of bentonite:- Montmorillonite Illite Kaolinite Bentonite

26. Welding/Joint Failure At Lapping:- Preventive Measure:- The Lapping should be done as per the specification and the bars should be bend properly. If the collapsed cage is at such a level than the cage should be taken out and after the inspection of the cage and if the collapsed cage is damaged then new cage should be placed. If above solution in not possible then that bore will be failed and at other point the piling should be done if necessary.

27. Welding/Joint Failure At Lapping:- Solution:- For lapping of steel reinforcement instead of welding the steel bars. Threading should be done in the bars and it should be tightened and then it should be welded.

28. Tremie Pipe Problem:- Preventive Measure:- The tremie pipe should be taken out and when the entraps air fully comes out then again pipe is attached and work can be continued.

29. Tremie Pipe Problem:- Solution:- If PVC pipes are used then the joints become air proof and chances of blockage reduces. Light weight rigid plastic tremie should used or tremie made of fiber plastic should be used which are light in weight.

30. Suitability Of Pile Foundation:- This type of foundation is suitable under the following situations ; When the soil is very soft and solid base is not available at a reasonable depth to keep the bearing power within safe limits. When the grillage and raft foundation are very expansive. When the tower is very high carrying heavy concentrated loads. When it is necessary to construct a tower along the sea shore or river bed

31. S ite V isit P hotos AT- BAJAJ ENGINEERS

32. Conclusion After detailed study of our project, we are able to know different kind of problems like lapping problem, boring blade, hard strata problem etc. in construction of transmission line tower. This project is helpful for detailed analysis of problems and to find out suitability of type of foundation according to site condition for the same.

33. Thank You..!