Module 4 : Design of Shallow Foundations
Lecture 19 : Settlement [ Section19.4 : Problems ]
   
  Position 2 :
 

In this the footing B is at location 1 and footing A is at location 2. The calculations are done same as in position 1 case.

The calculations for the final settlement are given in table 4.16
 
Table 4.16 Final settlements for position 2
 

Layer

Depth z (m)


At center of each layer (t/m2)

Footing B

Footing A

Footing B

Footing A

Footing B

Footing A

1

1.5

2.2

1.60

3.40

0.0032

0.0027

2

2.5

2.6

0.82

2.84

0.0016

0.0023

3

3.5

3

0.49

2.40

0.0010

0.0019

4

4.5

3.4

0.33

2.06

0.0007

0.0016

5

5.5

3.8

0.24

1.78

0.0005

0.0014

 

 

 

Total settlement =

0.00695484

0.00998248

 

The calculations for time vs settlement graph is given in table 4.16

The graph of time (days) vs settlement (m) is plotted for both the footings which is given in fig. 4.71 and the graph of differential settlement is also plotted which is given in fig. 4.72. As seen from this graph the max differential settlement is 5.4mm (For second position).

  Compression of settlements:
  Position 1: Footing A at location 1
                    Footing B at location 2
  Position 2: Footing A at location 1
                    Footing B at location 2
 

Therefore, footings should be placed as in posisiton 2.

   
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