ABSTRACT
Example 5.2 If water in the well in example 5.1 is pumped out up to the bottom of the well, estimate the change in the pressures at points A and B given in Fig. Ex. 5.1.
Solution Change in pressure at points A and B
= decrease in water pressure due to pumping = 3 x 9.81 =29.43 kN/m2
= 0 decrease in water pressure due to pumping
= 3 x 9.81 = 29.43 kN/m2
Change in total pressure(i)
(ii) Change in effective pressure (iii) Change in pore water pressure =
Example 5.3 A trench is excavated in fine sand for a building foundation, up to a depth of 13 ft. The excavation was carried out by providing the necessary side supports for pumping water. The water levels at the sides and the bottom of the trench are as given Fig. Ex. 5.3. Examine whether the bottom of the trench is subjected to a quick condition if G
s =2.64 and e =0.7. If so, what is the remedy?
