Friday 10 February 2012

Pole Foundation

Foundation:
Foundation is required to support structure for transmission tower, lighting poles, and transformer erection etc in the field of electrical engineering.
For foundation of single wooden, concrete or steel pole, the pit is excavated to a required depth. Precast concrete poles or steel poles are inserted in the pit. Concrete mixture is poured layer by layer and is rammed every time. Mixture ratio is normally 1:2:4 of cement: san: stone.
Depth for foundation is generally 1/6 Th of the length of pole.

Typical depth of foundation pits are as follows:
Pole size (meter):                                          9 10        12        15        18
Depth of foundation:                                  1.5         1.7          1.8        1.8          2
Location of poles:
Poles are located at least 1.5meter away from fire hydrant, underground cable trench, and 5meter away from road boarder and railway

Height of the pole in distribution system-
10M, 12M, 14M
Span of the pole:
Residential area: 30 to 50m
Rural areas        : 50 to 60m

Foundation for 9 meter street pole                                                                       
a)      Lean concrete ratio-1:3:6 (cement: sand: stone)
Volume:  0.7X 0.7X0.15 = 0.0735M3
Cement required per M3= 220kg
Cement for above volume= 16.17 kg
b)     Pedestal PCC at ratio 1:2:4
Outer dia =0.540M
Inner dia= 0.15M
Height = 1.5M
Volume = π/4 x (D2-d2) x H
             = π/4 x (0.542-0.142) x 1.5
             = 0.321M3
Cement required for ratio 1:2:4 @ =320kg per M3
For 0.321 M3 volume cement required = 320 x 0.312 = 102.72kg
c)      Copping ratio 1:2:4
Outer dia =0.30M
Inner dia= 0.14M
Height = 0.3M
Volume = 0.021M3- 0.004M3)
             = 0.017M3

Total cement consumption per pole =a+b+c = 16.17 +102.72+ 5.44 = 124.33kg



Earth pit chamber:
Plaster 1:4 cement =5.47kg/M3
Brick masonry 2x0.6x0.45x0.115=0.062M3
                       2x0.3x0.45x0.115=0.031M3
                                      -------------
                                          0.093M3

Cement consumption: 0.093x95=8.835kgs
Plaster 4x0.3x0.45 = 0.54M3
            4x0.6x0.1 = 0.24M3
            2x0.3x0.15 = 0.09M3
                                ------------
                                1.05x5.47 = 5.749kg
Total cement consumption
 For one earth pit chamber = 14.58kg

FOUNDATION OF FEEDER PILLAR & TELEPHONE DB    
1. Lean concrete: 1:3:6
Cement 0.11x 220kg/M3
2. Brick work = 2x1.0x0.5x0.075= 0.075M3
                        2x0.5 x0.35x0.6= 0.21M3
                             0.9 x0.5x0.3 = 0.135
-------------------------------------------------
Total                                          =0.42M3

Cement = 0.42x95kg/M3 (1:4 mortar)
                 =39.9 kg
3. Plaster 12 mm thick
0.9 x0.3x2 = 0.54M2
    Total  = 0.84M2
Cement: =0.84x547kg/100M2
                =4.6kg
4. Neat coat =1.7kg@1.9kg/M2 for area of 0.84M2
Total cement for one foundation = 70kg

Foundation of post top fixture
a)      Lean concrete ratio-1:3:6 (cement: sand: stone)
Volume:  0.7X 0.7X0.15 = 0.0735M3
Cement required per M3= 220kg
Cement for above volume= 16.17 kg
b)      Pedestal PCC at ratio 1:2:4
0.5x0.5x0.1 = 0.25M3x320 =80kg
Height = 1.5M
Cement required for ratio 1:2:4 @ =320kg per M3
c)      Copping ratio 1:2:4
 0.3x0.3x0.045x320=14.40kg

Total cement consumption per pole
=a+b+c = 16.17 +80+ 14.4 = 110.57kg

12 comments:

  1. Great information to read, i learns a lot while reading this post. thanks for this blog vrla batteries | gel batteries

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  2. Excellent information posted here. If you are looking for rolling shutter wire then contact only at Precision Drawell

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  3. In certain applications the poles are directly mounted onto an existing structures. Base plates are bolted onto Foundation Bolts.
    Power transformers in India | Transformer manufacturer in India

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  4. Kindly Guide For 7 Feet Fencing Pole What is concrete Required and for the Pit Size of 2 x 2

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  5. you have not shown depth. consider it and calculate as in example.

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  6. we r going to start costruction of electric pole foundation for railways & interested for more informations.

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  7. please advise me concreat base foundation size required for 7 mtr street light pole.

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  8. Pedestal need to have concrete base footing resting on soil to transfer vertical downward load & horizontal wind force & moment

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  9. We need advise for this problem. This is for fencing our Agri land. we have to fence about 270 poles including border ones - we have decided to keep 10 feet distance between poles. So perimeter is 2700 feet. Each Pole is 9 feet length, 6 in * 6 in square. We will dig 3 feet with Earth Auger and the circular Dug hole will be 12 inches ( 30cm) dia. Each hole and erect 3 feet inside and 6 feet above ground.
    Our question is " Do we need to use concrete for pouring into the ground? for strengthening (or) can we have stones and loose soil to close the space between Earth and the Pole which is 3 feet.
    Please reply.

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  10. This comment has been removed by the author.

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  11. These diagram are very impressive. Technopole Industries is the no 1 street light pole manufacturer in UAE

    ReplyDelete

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