CALCULATION OF WATER CURRENT FORCES :-

CALCULATION OF WATER CURRENT FORCES :-

Mean velocity of water current at HFL ,V 0.5

Max. velocity at surface , V = (2) *V 2

V at HFL Case 1: 

=

7.0 m/ m/s

=

9.90 m/s

=

98.0 m/s o 

Water current force for norm al case, water flowing at 0 

Value of "K"

=

0.66

Pier shaft width at top (m)

=

2.68

Pier shaft width at base (m)

=

2.0

Water current force diagram  3.363t/m2

HFL 94.875 F

Intensity of pressure due to water  2

2

current at HFL, 52KV (t/m )

=

3.363

Intensity of pressure due to water  2 at well cap top level (t/m ) =

1.853

80.200 Top of  well cap

Water current force on pier upto end of varying portion, F (t ) =

47.5

Level at which force F acts

89.876

=

1.853t/m2

Normal scour  level 62.200

Case 2: 

o 

Water current force for n orm al case, water flowing at 20 

Value of "K" along transverse direction

=

0.66

Force at base of pier along transverse direction ( taking cosine component of the value as calculated above & multiplying with the appropriate obstruction width)

=

41.9 41.95 5 t

Value of "K" along longitudinal direction

=

1.50

Force at base of pier along transverse direction ( taking sine component of the value as calculated above & multiplying with the appropriate obstruction width) Water current force on pier upto end of varying portion, F (t ) =

56.2

Level at which force F acts

94.162

=

3.90m

Pier cap top Level RL 95.950 3.46m

HFL RL 94.875

1.00m

pier centre line

H=

14.68m

2.00m

OBSTRUCTION DIAGRAM IN TRANSVERSE DIRECTION

RL 80.200 Top of well cap

11.00m

Pier cap top Level RL HFL RL

95.95 94.875

10.10m

5.00m

pier centre line

14.68m

RL 80.200 Top of foundation / well cap

6.00m

OBSTRUCTION DIAGRAM IN LONGITUDINAL DIRECTION

2

V at HFL Case 3: 

=

98.0 m/s o 

Water current force for seism ic case, water flowing at 0 

Value of "K"

=

0.66

Pier shaft width at top (m)

=

2.14

Water current force diagram  3.363t/m2

Pier shaft width at base (m)

=

HFL 94.875

2.00 F

Intensity of pressure due to water  2

2

current at HFL, 52KV (t/m )

=

3.363

Intensity of pressure due to water  2 at well cap top level (t/m ) =

1.685

80.200 Top of  well cap

Water current force on pier upto end of varyi ng porti on, F (t) =

45.7

Level at which force F acts

88.886

=

1.685t/m2

Seismic scour  level 65.460 Case 4: 

o 

Water current force for seism ic case, water flowing at 20 

Value of "K" along transverse direction

=

1.50

Force at base of pier along transverse direction ( taking cosine component of the value as calculated above & multiplying with the appropriate obstruction width)

=

40.34 t

Value of "K" along longitudinal direction

=

1.50

Force at base of pier along transverse direction ( taking sine component of the value as calculated above & multiplying with the appropriate obstruction width) Water current force on pier upto end of varying portion, F1 (t) =

54.7

Level at which force F1 acts

94.303

=