Anchor Block Stability Analysis

ANCHOR BLOCK STABILITY ANALYSIS Input Value f f'

w

Unit

Input

Value

Unit Forces Acting on Anchor Block

0.6

-

W

61930

N

1.) Hydrodynamic force acting along axis of pipe on each side bend (Fs)

124800

-

P'

21950

N

2.) Dynamic force acting against outside of bend (Fd)

W'

10417

N

3.) Force due to dead weight of pipe from anchor uphill to expansion joint tending to slide downhill over pier (Du)

1000 kg/m3

A

1.7671459 m2

αu

0.61087

4.) Force due to dead weight of pipe from anchor downhill to expansion joint tending to slide downhill over pier (Dd)

A'

1.7671459 m2

αd

0.61087

5.) Sliding friction of pipe on piers due to expansion or contraction uphill from anchor (Spu)

A'' H t

1.7671459 m2 50 m 10 mm

p p' d

75633.9 N 126035 N 1.5 m

6.) Sliding friction of pipe on piers due to expansion or contraction downhill from anchor (Spd) 7.) Sliding friction of uphill expansion joint (Sou) 8.) Sliding friction of downhill expansion joint (Sod)

Q

7.6666667 m3/s

a

0.047

9.) Hydrostatic pressure on exposed end of pipe in uphill expansion joint (Fu)

V

4.3384459 m/s

a'

0.047

10.)Hydrostatic pressure on exposed end of pipe in downhill expansion joint (Fd)

e

6.4

μ k

0.26 300

g P

9.81 m/s2 13163.9 N

m

11.) Longitudinal Force due to reducer above anchor (Lu) 12.) Longitudinal Force due to reducer below anchor (Ld)

f 0.5 For Sliding Stability f =H/F F=V+Wa+Wp+w H horizontal component of the forces V Vertical component of the forces Wa Weight of the anchor Wp+w Weight of the pipe and water supported by the anchor Wa= 2H +V + Wp+w 2339913.07 N 2339.91307 kN 233.991307 ton For three units Wa 701.97392 ton Factored load 1123.16 Volume of Anchor Block 1165 m3 Wt. of block 2796 ton FOS 2.48941

Vertical

Formula wAH

Results Horizental Comp. Component (N) of Forces (N) of Forces (N) 883573 723780.575018819 506796.61464

Q w V/g

33905.63

27773.862119628 19447.467621

P Sin αu

7550.503

6185.0098453818 4330.7905176

P' Sin αd f Cos αu(P+W-p'/2)

12590 10313.1265131253

7221.328927

18321.29 15007.9253345231 10508.662452

f Cos αd (P-W'-p'/2) -29622.5 -24265.3077750972 -16990.751421 f' П (d+2t)/1000 8429.521 6905.0596938329 4834.9748494 f' П (d+2t)/1000 8429.521 6905.0596938329 4834.9748494 W Hn t (d+t)/10^6 =waH

23500 19250.0730407913 13479.046254

w a' H

23500 19250.0730407913 13479.046254

w H (A'-A)

0

w H (A-A')

0 sum

0

0

0 0 0 0 811105.456525629 567942.15494

Refrence - HYDRO POWER STRUCTURES R. S. VARSHNEY

U/s penstock angle w.r.t. horz. α 0 Uphill ground slope i 0 D/s penstock angle w.r.t. horz. Β 35 Half Dist. To u/s support pier L1u 2.5 Half Dist. To d/s support pier L1d 2.735 Dist. To u/s expansion joint L4u 10.98 Dist. To d/s expansion joint L4d 4.33 Dist. b/w two cons support piers u/s L2u 6 Dist. b/w two cons support piers d/s L2d 6 f for steel on steel 0.25 No of Piers 8 h gross 39 m h surge m H total 39 Unit Weight of Soil 20 Buried depth 7.47 width 16.63 Ka 0.45 Discharge, Q 23 pipe diameter 1.5 m thickness of pipe 10 mm Volume of the block plus panel 1165 m3 Weight of the block Wb= 27960 kN Weight of Pipe Wp= П (d+t)*t Yst 3.65 kN/m Weight of Water Ww = 17.335700962 kN/m Wp+Ww= 20.99 kN/m

F1u F1d F2u F2d F3 F4u F4d F5 F6 F7u F7d F8 F9 F10 Wb Sum

Positive (kN) Negative(kN) 52.4710768498 47.0220781151 251.861168879 251.861168879 406.35878216 23.0044146267 9.0718684275 0 150 18.2559 18.2559 176.748186598 0 4175.8603515 2330

Calculation of Relevant Forces Forces (kN) X-component (kN)+ F1u F1d F2u F3 F4u F6 F7u F7d F8 F10

Y-Component +