We have already learnt about liquefaction of soil during earthquake ground motion. Here we will learn about the vibration characteristics that can produce liquefaction or can a machine vibration generate liquefaction?
Settlement behavior and liquefaction as well depends on following properties of dynamic loading
-nature of dynamic loading
-magnitude of dynamic loading
-type of dynamic loading
Now we will list some valuable findings from various researchers:
Ivanov and Florin, 1961
Liquefaction may begin from top and progress downward when soil mass is subjected to steady state vibration. The soil mass must fulfill the degree of saturation, grain sizes etc. that is essential condition for liquefaction.
Lee and Seed (1966), Gupta and Prakash (1970):
Maximum pore water pressure is an important term in liquefaction we will discuss about this term in our upcoming posts.
“When soil mass is subjected to steady state vibrations, maximum pore water pressure is developed only when the deposit is subjected to a number of cycles is completed.”
Gupta and Prakash (1967):
They provide a relation between horizontal and vertical vibration.
“It is observed in general cases that when a deposit of dry sand is subjected to horizontal vibration it suffers more settlement than that from vertical vibration.
The saturated soil also shows identical behavior.”
Dear reader we will finish this topic in next part where we will discuss about liquefaction occurred in Great Alaskan Earthquake and duration required for commencing liquefaction.