# Goswami Retaining Wall with Water Table Problem



## RJs (Oct 9, 2010)

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.


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## civilized_naah (Oct 9, 2010)

RJs said:


> 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


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## RJs (Oct 10, 2010)

Thanks Civilized naah for calrifying.


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