Lecture 7 - Lateral Earth Pressure

LATERAL EARTH PRESSURE

EARTH PRESSURE TYPES

At-rest (Po & Ko)

Active (Pa & Ka)

Passive (Pp & Kp)

At-Rest Pressure

The retaining wall is not

allowed to move away or toward the retained soil.

At-Rest Pressure

The retaining wall is not

allowed to move away or toward the retained soil.

Active Earth Pressure

The retaining wall is

allowed to move away from the retained soil.

Active Earth Pressure

The retaining wall is

allowed to move away from the retained soil.

Active Earth Pressure (Rankine Theory) The retaining wall is

allowed to move away from the retained soil.

Active Earth Pressure The retaining wall is

allowed to move away from the retained soil.

Passive Earth Pressure The retaining wall is

allowed to move away

from the retained soil.

Passive Earth Pressure

The retaining wall is

allowed to move towards the retained soil.

Passive Earth Pressure (Rankine Theory)

The retaining wall is

allowed to move towards the retained soil.

Passive Earth Pressure

The retaining wall is

allowed to move towards

the retained soil.

TYPES OF EARTH PRESSURE

Po or Ko

Pa or Ka

Pp or Kp

Away from Soil D x/H Into Soil

D x

H

D x

H

ACTIVE PASSIVE

ACTIVE AND PASSIVE PRESSURES

Change is nonlinear

Small movement is needed to produce full active condition

Large movement is needed to produce full passive condition

Coulombs Active Pressure

Coulomb theory accounts for three factors that were not

accounted for in the original Rankine theory:

The wallsoil interface friction Sloping backfill soil Inclination of the retaining wall

Coulombs Active Pressure

Coulombs Active Pressure

Coulombs Passive Pressure

Coulombs Passive Pressure

Solucin Grfica

EARTH PRESSURE DISTRIBUTION

H

g & f

P

H/3

Ground Surface

Ground Surface

AT-REST EARTH PRESSURE

AT-REST EARTH PRESSURE