Goswami Retaining Wall with Water Table Problem

[RJs]

Can someone who is using Indranil Goswami's All in One book, explain how the horiznotal force due to watertable was calculated as 7848 lb in Problem # 208.2 Retaining Wall with Ground water table? I just couldnt understand at all!!!

Thanks in advance.

 

[civilized_naah]

Can someone who is using Indranil Goswami's All in One book, explain how the horiznotal force due to watertable was calculated as 7848 lb in Problem # 208.2 Retaining Wall with Ground water table? I just couldnt understand at all!!!Thanks in advance.

Assuming you are OK with how the 1121.2 psf was calculated, the triangular component 4c has a resultant = 0.5x14x1121 = 7848 lb

A shortcut to calculate the TOTAL horizontal stress = K times TOTAL vertical stress + (1-K) times pore water pressure. This would give:

At elev 129: p_h = 0.307 times (3x120) + (1-0.307) times zero = 110.5

At elev 115: p_h = 0.307 times (17x120) + (1-0.307) times (14x62.4) = 1231.7

The 110.5 is then subtracted out of 1231.7 to give the triangular (4c) component 1121.2, whose resultant is 7848

 

[RJs]

Thanks Civilized naah for calrifying.