Example of Foundation depth and arrangement:
For example, if the maximum discharge of a river is 1000 cu m per sec, and the silt factor is 0.60, the maximum scour depth is :
D = 0.473 (1000) 1/3/f1/ 3
= 0.473 × 9.98 1/3/0.84
= 5.62 m
The depth of the foundation below the high flood level is then 1.33 × 5.62 = 7.47 or 7.5 m.
The well foundation consists of:
(a) well curb with cutting edge
(b) well steining
(c) bottom plug
(d) sand filling
(e) top plug
(f) well cap
A typical arrangement of a well foundation is given in Figure.
Figure: Details of Well Foundation