lateral earth pressure and types vedio link https://youtu.be/inpTybhhogI

1. TOPIC
LATERAL EARTH PRESSURE & ITS TYPES
SUBJECT: FOUNDATION ENGINEERING
PART – I
PREPARED
BY
ER.SANJEEV SINGH
EMAIL: SNJV432@GMAIL.COM

2. CONTENTS
 Lateral Earth Pressure
 Types of earth pressures
 Coefficients of earth pressure - Earth Pressure
Coefficient

3. LATERAL EARTH PRESSURE
 In 1929 Terzaghi (The Father of Soil Mechanics) conducted
experiments on the retaining wall and showed the relation
of pressure on the wall if wall changes its position. i.e to
move inwards to the backfill, outwards of it or remain at its
place.

4. There are three types of earth
pressures on the basis of the
movement of the wall.
Earth
Pressure
at rest
Active
Earth
Pressure
Passive
Earth
Pressure

5. EARTH PRESSURE AT REST
 The lateral earth pressure is called at rest pressure when the soil mass is
not movement.
 This case occurs when the retaining wall is fixed at its top and is not
allowed to rotate or move laterally.
 Fig show the basement retaining walls which are restrained against the
movement by basement slab provided their tops.
 The at – rest condition is also known as the elastic equilibrium ,as no
soil mass has failed and attained the plastic equilibrium.
 Coefficient of earth pressure at rest:
Ko = lateral pressure / vertical pressure

6. ACTIVE EARTH PRESSURE
 A state of active pressure occurs when the soil mass yields in such
a way that it tends to stretch horizontally.
 It is a state of plastic equilibrium as the entire soil mass is on the
verge of failure.
 A retaining wall when moves away from the backfill, there is a
stretching of the soil mass and the active state of earth pressure
exist.
 Coefficient of active earth pressure
Ka = lateral pressure / vertical pressure

7. PASSIVE EARTH PRESSURE
 A state of passive pressure exists when the movement of the wall
is such that the soil tends to compress horizontally.
 Fig show the passive pressure develops on the left side of the
wall below the ground level, as the soil in this zone is
compressed when the movement of the wall is towards left.
 Coefficient of passive pressure
Kp = lateral pressure / vertical pressure