FLOOD03439

• County: Statewide
• Basin: Statewide
• Title: Design of Sheet Pile Walls
• Date: 3/31/1994
• Prepared By: US Army Corps of Engineers
• Floodplain - Doc Type: Educational/Technical/Reference Information

EM 1110-2.2504
31 Mar 94

24
. r CLASSICAL E/JRTH PRESSURE
IIAXIIIUU VALUE FOR 8 - 0
..
D.
:;c 20
.
....
U
II:
0
"- 16
.... . TRANSLATING WALL
II: -J I-A
::0
VI
VI
.... I, r. t:t:
II: 12 I, "
n. II "
I. I'
:J: " I' Q
.... I, II
~ . ROTATING WALL
.... 8
~ -J I-A
....
z
0 t
N
it: 4 Q:t:
0
:J:

o
0.22

y -110 lB/fT3
<I> - 35.
K - 270
n - 0.5
Rfa 0.8
II - 0.3
8-0

CLASSICAL
E/JRTH PRESSURE
IIINIIIUII VALUE FOR
8 - 07

0.18

0,14 0.10 0.06 0,02 0 0.02 0.06 0.10 0.14
_ TOWARD BACKFill A IFEETI AWAY FROM BACKFlll-

.

Figure ....3, Ver.tlona 01 Nrth preaaure force with well move_nt celcu.ted by finite "e_nt enelya.. (after
Clough end Duncen 1871)

sIresseS due to wa1l/soil friction in !he case of granular
soils or in wal1lsoil adhesion for cohesive soils. lbis
will have an effecl on !he magnitude of !he minimum
and maximum horizonlal earth pressures. For Ihe mini-
mum or active limil slale. wall friction or adhesion will
slighlly decrease the horizonl31 earth pressure, For !he
maximum or passive limil stale. wall friction or adhe-
sion may significanlly increase the horizonlal earth
Pressure depending on ils magnilUde.

4-3. Eanh Pressure Calculations

Several earth pressures Iheories are available for esti-
mating !he minimum (active) and maximum (passive)
1aIera1 earth pressures Ihat can develop in a soil mass
surrounding a wall, A detailed discussion of various
theories is presented by Mosher and Oner (1989). The
Coulomb !heery for IaIera1 earth pressure will be used
for the design of sheet pile walls.

.

Q. Coulomb Theory. 1be evaluation of !he earth
pressures is based on Ihe assumption Ihat a failure plane
develops in the soil mass. and along Ihat failure the
shear and lIOI1Ilal forces are related by !he shear streng!h

expression (Equation 4-2). This makes !he problem
s1atica1ly delenninale. Free-body diagrams of a wedge
of homogeneous soil bounded by Ihe soil surface. !he
sheet pile wall. and a failure plane are shown in Fig-
. ure 4-4. Equilibrium analysis of Ihe forces shown in
Figure 4-4 allows !he active force. p., or passive force,
P p' to be expressed in lenns of Ihe geometty and shear
strenglh:

"f = unit weight of Ihe homogeneous soil

. = angle of inlcma1 soil friction

c = cohesive stteng!h of the soil

Ii = angle of wall friction

.9 = angle between !he wall and !he failure plane

z = deplh below Ihe ground surface

p = slope of the soil surface

For !he limit stale (minimum and maximum), active or
passive. the angle i, aitical angle at failure. is obtained
from dPld9 = O. Finally, !he soil pressure at deplh z is
.oolained from p . dPldz. These operations resull in

4-3