Liquefaction is most catastrophic after landsliding in terms of economic and human life loss.

1. Liquefaction

2. Group Members
 Basit Ahmad (2018-MS-CEG-14)
 Gulraiz Arshad (2018 –MS-CEG-18)
CIVIL ENGINEERING DEPARTMENT
UET LAHORE

4. What Is Liquefaction
Liquefaction is the name
given to the process that
converts a solid soil mass
into a liquid.

5. What is Soil Liquefaction
A phenomenon whereby a saturated or
partially saturated soil substantially
loses strength and stiffness in response
to an applied stress, usually
earthquake shaking or other sudden
change in stress condition, causing it
to behave like a liquid.

6. When does it occurs
When the effective stress of
soil is reduced to essentially
zero, which corresponds to a
complete loss of shear strength

7. Niiagata Earthquake in Japan (1964)

8. When does it Occurs
 Liquefaction occurring beneath buildings
and other structures can cause major
damage during earthquakes.
 Liquefaction occurs in cohesion less soils
(typically those with a higher content of
larger grains such as sand sized) which have
water in the pore spaces, and are poorly
drained.

9. How It Works
 When the seismic waves pass through the soil, the
vibrations cause the individual grains in the soil to
 move around and
 re-adjust their positions
 This ultimately results in a decrease in volume of the
soil mass as
 the grains pack more tightly together
 a reduction in porosity

10. How It Works
 The pore water which was originally in those
spaces becomes compressed.
o increase in pore water pressure.
 The pore water pressure becomes so high, that
the soil grains become almost Floats
o causing a significant drop in the shear strength

13. Effects of Liquefaction
The shear strength of soils becomes very low

14. Buildings may tilt or sink

15. Loss of
Economic and
Human Life

16. What are
the options
for
liquefaction
mitigations?

17. Abandon the site

18. Replacement of Soil

19. Vibrocompaction

20. Jet Grouting

21. Vibro Stone
Column

22. By Passing
Liquefiable Soil