Civil Engineering Reference
In-Depth Information
The lateral earth pressure developed behind the rigid frames at the end of the
last expansion cycle is shown in Fig. A.47. As established from earlier results, the
pressure is found to increase with the increase in the number of bays. The maxi-
mum pressure magnitude, however, found for the 10-bay frame with a length of
200 feet, is smaller than its counterpart developed for the frames with similar
length discussed previously. This frame also has the smallest lateral stiffness of all
frames with the same length presented thus far (for the backfill soil with the 40º
internal friction angle) as indicated in Table 7.2 of Chapter 7. Additionally, the
earth pressure magnitude is found to peak only close to the top of the wall and de-
crease rapidly towards the bottom, more rapidly than the frames with 10-ft bay
length.
The retaining wall moments at backfill stage are shown in Fig. A.48. The
moment magnitude at the top of the wall for all three frames is larger than its
counterpart found for the frames with 10-ft bay length presented earlier.
10
8
6
L
b
= 20 ft
φ
4
M
bn1
M
bn3
M
bn10
= 40
o
2
S
c
/S
b
= 1
0
-10
-5
0
5
Retaining Wall Moment, M, kips-ft
Fig. A.48
Retaining Wall Moment at Backfill Stage (φ = 40º, All Bays, L
b
=20 ft, S
c
/S
b
= 1)
10
8
6
L
b
= 20 ft
φ
4
M
en1
M
en3
M
en10
= 40
o
2
S
c
/S
b
= 1
0
-10
-5
0
5
Retaining Wall Moment, M, kips-ft
Fig. A.49
Retaining Wall Moment at Expansion (
φ
= 40º, All Bays, L
b
=20 ft, S
c
/S
b
= 1)
