
Retaining Wall Design Problem 4  Check Stability And Design Steel Reinforcement:

Given the proposed retaining wall below, check the resistance to sliding, the turnover stability, the bearing capacity and calculate the required areas of steel reinforcement for a proposed retaining wall. 

1. From the retaining walls submenu open the resistance to sliding  no key calculation, RSlidingWedge.aspx. Input the "Title" of the calculation, the "Designer/Checker" information and the variables.
Click on the "Calculate" button. Read the results. The resistance to sliding is 31,555.734 lbs/ft which is greater than
27,620 lbs/ft therefore the sliding resistance is adequate.


2.
From the retaining walls submenu open the eccentricity and maximum and minimum soil pressure calculation, RwallEcc.aspx. Input the "Title" of the calculation, the "Designer/Checker" information and the variables.
Click on the "Calculate" button. Read the results. The maximum soil pressure is 5,067.635 lb/ft and the minimum soil pressure is 573.365 lb/ft.


3.
From the retaining walls submenu open the bearing pressure resultants calculation, BPResultants.aspx. Input the "Title" of the calculation, the "Designer/Checker" information and the variables.
Click on the "Calculate" button. Read the results. The calculated bearing pressure resultants are as calculated below. The entire base is in compression, therefore the overturning stability is Ok.


4.
From the retaining walls submenu open the check bearing capacity calculation, BearingCap.aspx. Input the "Title" of the calculation, the "Designer/Checker" information and the variables.
Click on the "Calculate" button. Read the results. The calculated bearing capacity Factor of Safety, FS is 6.234. The bearing capacity is Ok.


5.
From the retaining walls submenu open the stem wall reinforcement calculation, RStem.aspx. Input the "Title" of the calculation, the "Designer/Checker" information and the variables.
Click on the "Calculate" button. Read the results. The required area of steel of the stem wall reinforcement is 3.139 sq in. The minimum temperature shrinkage steel area is 0.778 sq in.


6.
From the retaining walls submenu open the heel reinforcement calculation, RHeel.aspx. Input the "Title" of the calculation, the "Designer/Checker" information and the variables.
Click on the "Calculate" button. Read the results. The required area of steel of the heel reinforcement is 3.131 sq in.


7.
From the retaining walls submenu open the toe reinforcement calculation, RToe.aspx. Input the "Title" of the calculation, the "Designer/Checker" information and the variables.
Click on the "Calculate" button. Read the results. The calculated required area of steel of the toe reinforcement is 0.903 sq in. The steel ratio is 0.002 with the minimum steel ration pmin = 0.004. Therefore use the minimum steel ratio As = 0.004(364.5)(12) = 1.512 sq in.


8. Summary

The resistance to sliding is Ok. The entire base is in compression, therefore the overturning stability is Ok. The calculated bearing capacity Factor of Safety, FS is 6.234, therefore the bearing capacity is Ok.
The required area of steel of the stem wall reinforcement is 3.139 sq in. The minimum temperature shrinkage steel area is 0.778 sq in. The required area of steel of the heel reinforcement is 3.131 sq in.
The required area of steel of the toe reinforcement is as required by the minimum steel ratio, 1.512 sq in.

