CIVL 451 Foundation Engineering
Fall 2010-2011
Final Exam
3h
1
2
3
4
Total
Name:...................................................................No...............................
1. For the column loads and moments given in the figure below,
(a) Determine L and B of a rectangular combined footing to provide
a uniform base pressure distribution. (10%)
(b) Determine the effective depth, d of the rectangular combined
footing. (10%)
(c) Determine the end dimensions, a and b for a trapezoidal
combined footing using the given data. (10%)
Given: w1x w1= 30 x 30 cm, w2x w2= 30 x 30 cm, w3x w3= 40 x 40 cm, w4x w4= 50 x50 cm,
fc’= 21 MPa, fy= 400 MPa, qall= 150 kPa.
120 kN-m
D= 1000 kN
L= 400 kN
D= 1200 kN
L= 400 kN
4m

400 kN-m
255 kN-m
D= 1600 kN
L= 400 kN
3m

200 kN-m
D= 2000 kN
L= 400 kN
2.5 m


2. For the proposed mat foundation below,
(a) Determine the base pressure distributions at all points from A to L.
(19%)
(b) What should be the safe thickness of the mat. (6%)
Given: Column dimensions: 50 x50 cm, qall= 100 kPa.
A
B
500 kN
C
1000 kN
D
800 kN
1200 kN
5.0 m
L
700 kN
2000 kN
2500 kN
E
850 kN
3.5 m
K
850 kN
2500 kN
2200 kN
F
900 kN
5.0 m
900 kN
1200 kN
J
9.0 m
I
5.5 m
1500 kN
H
1000 kN
G
9.0 m
Check the complete stability of the cantilever retaining wall shown.
(concrete= 24 kN/m3) (28%)
0. 85
m
c= 0
= 35
= 20 kN/m3
10 m
2m
5m
0.85 m
1m
0.85 m
8.5 m
c= 50 kPa
= 20
= 22 kN/m3
4. A piled foundation system is as shown in the figure below.
(a) Determine the allowable single pile capacity, and state if the
design is safe for the given load. Assume concrete piles of
diameter 500 mm. (FS= 4) (10%)
(b) Determine the group efficiency. (3%)
(c) What will be the group capacity? (2%)
(d) Will the pile group carry the given load safely? (2%)
Lg
4m
Bg
3m
Qg= 6000 kN
2m
Sand
= 30
 = 19 kN/m3
30 m