Problem 2: Using the information you gained from the previous problem 1 (below) for lateral pressure...

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Problem 2: Using the information you gained from the previous problem 1 (below) for lateral pressure and a groundwater table at Level B, compute again the lateral earth pressures and compute the...

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Problem 2: Using the information you gained from the previous problem 1 (below) for lateral pressure and a groundwater table at Level B, compute again the lateral earth pressures and compute the hydrostatic pressures acting on the back of the wall. Present your results in the form of a pressure diagram, and then compute the total normal force acting on the wall. Compute the bending moment at the bottom of the stem. Compare your results to the previous problem 1 (previous problem results are shown below). Problem 1: Using the groundwater table at level A and Rankine’s method, compute the lateral earth pressure acting on the back of the concrete wall in figure 1. Present your results in the form of the pressure diagram, and then compute the total normal force acting on the wall and the bending moment at the bottom of the stem. Figure 1: 12 ft Fine to Medium Sand C’=0 and ?’=36 degrees Unit Weight = 122 ???? ???? 3 Unit Weight Saturated = 127 ???? ???? 3 4 ft 10 ft B A Solution: ???? = tan2 (45° - Ø ' 2 ) = ?????? XXXXXXXXXX ) = 0.260 ?? = ???? '???????????? = ???????????????? = 122???? ???? 3 (?? XXXXXXXXXXcos(0) = 31.7?? ?????? ???? ???????? ?? = 0 ???? = 0 (?????? ????????????????) ???????????? ???? ???????? ?? = 12???? ?? = 31.7?? = XXXXXXXXXX????) = 380 ???? ???? 2 ???????????? ???????????? = XXXXXXXXXX ???? ???? XXXXXXXXXX????) = 2880 ???? ???? ???????????? ???? ???????????? = 2280 ???? ???? 3 (12 ???? 3 ) = 9120 ???? - ???? ????Problem 2: Using the information you gained from the previous problem 1 (below) for lateral pressure and a groundwater table at Level B, compute again the lateral earth pressures and compute the hydrostatic pressures acting on the back of the wall. Present your results in the form of a pressure diagram, and then compute the total normal force acting on the wall. Compute the bending moment at the bottom of the stem. Compare your results to the previous problem 1 (previous problem results are shown below). Problem 1: Using the groundwater table at level A and Rankine’s method, compute the lateral earth pressure acting on the back of the concrete wall in figure 1. Present your results in the form of the pressure diagram, and then compute the total normal force acting on the wall and the bending moment at the bottom of the stem. Figure 1: 12 ft Fine to Medium Sand C’=0 and ?’=36 degrees Unit Weight = 122 ???? ???? 3 Unit Weight Saturated = 127 ???? ???? 3 4 ft 10 ft B A Solution: ???? = tan2 (45° - Ø ' 2 ) = ?????? XXXXXXXXXX ) = 0.260 ?? = ???? '???????????? = ???????????????? = 122???? ???? 3 (?? XXXXXXXXXXcos(0) = 31.7?? ?????? ???? ???????? ?? = 0 ???? = 0 (?????? ????????????????) ???????????? ???? ???????? ?? = 12???? ?? = 31.7?? = XXXXXXXXXX????) = 380 ???? ???? 2 ???????????? ???????????? = XXXXXXXXXX ???? ???? XXXXXXXXXX????) = 2880 ???? ???? ???????????? ???? ???????????? = 2280 ???? ???? 3 (12 ???? 3 ) = 9120 ???? - ???? ????

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Answered Same Day Dec 26, 2021

Solution

Robert answered on Dec 26 2021

127 Votes

Question B
Problem 2: Using the groundwater table at level A and Rankine’s method, compute the
lateral earth pressure acting on the back of the concrete wall in figure 1. Present your
esults in the form of the pressure diagram, and then compute the total normal force
acting on the wall and the bending moment at the bottom of the stem.
Solution:
If the cohesion, c, is equal to zero
For the top soil layer,  = 36o, so
)
2
45(tan 2

aK
)
2
36
45(tan 2 aK
Ka=0.259
Active earth pressure coefficient
Ka=0.259
' '
a v aK 
Because of the presence of the water table below the height of retaining wall So, there
is no any effect of hydrostatic pressure
At z = 0,
At z = 12 ft,
zv  
'
psfv 146412122
' 
vaa K
''  
psfa 176.3791464259.0
'  Z=0

Z=12ft 379.176psf

The pressure distribution diagram is plotted above. Then, the force per unit length:
Pa=Area of triangle
Pa=1/2xBasexHeight=1/2x379.176x12=2275.056 l
ft.
This will act at distance Z/3 from the bottom of wall ( i.e. from stem) i.e. 12/3= 4 feet
The moments about the bottom of the...

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Please complete assignment1 and project portfolio. Contents for project portfolio is in the assessment 2 file itself. thankyou.
Solved Feb 01, 2025

Robert · Accepted Answer

Question B 
Problem 2: Using the groundwater table at level A and Rankine’s method, compute the 
lateral earth pressure acting on the back of the concrete wall in figure 1. Present your 
results in the form of the pressure diagram, and then compute the total normal force 
acting on the wall and the bending moment at the bottom of the stem.
Solution:
 If the cohesion, c, is equal to zero
For the top soil layer,  = 36o, so
)
2
45(tan 2

aK
)
2
36
45(tan 2 aK  
Ka=0.259 
Active earth pressure coefficient  
Ka=0.259
' '
a v aK 
Because of the presence of the water table below the height of retaining wall So, there 
is no any effect of hydrostatic pressure
At z = 0,
At z = 12 ft,  
zv  
'  
psfv 146412122
' 
vaa K
''  
psfa 176.3791464259.0
'                     Z=0 
 
 
 
 
 
 
              Z=12ft     379.176psf 
 
 
 
 
The pressure distribution diagram is plotted above.  Then, the force per unit length: 
Pa=Area of triangle 
Pa=1/2xBasexHeight=1/2x379.176x12=2275.056 lb/ft.
This will act at distance Z/3 from the bottom of wall ( i.e. from stem) i.e. 12/3= 4 feet
The moments about the bottom of the wall=Pax4=2275.