A silty/clayey gravel stratum, SPT sampling, 25-35 ft depth with water table at 18 feet. Loose to medium dense. SPT samples yield fragments of larger gravels which, coupled with experience in the area, indicates to us that there is a significant percentage of cobbles to gravels. Liquefaction determination per Idriss and Boulanger 2008 indicates liquefaction for the MCE per ASCE 7-16.
In our practice here in Jackson Wyoming, we commonly run into cohesionless cobble/gravel/sand alluvium below the water table-in almost all case density /shear wave velocity is too high for liquifaction-never had to deal with this issue before.
Kramer 1996 has a general statement that poorly graded angular gravels and cobbles are less susceptible to liquefaction. The paper below regarding ejected material which would seem to indicated D50 over a certain size is not liquefiable. Is there a definitive reference or references regarding particle size vis a vi liquifaction?
In our practice here in Jackson Wyoming, we commonly run into cohesionless cobble/gravel/sand alluvium below the water table-in almost all case density /shear wave velocity is too high for liquifaction-never had to deal with this issue before.
Kramer 1996 has a general statement that poorly graded angular gravels and cobbles are less susceptible to liquefaction. The paper below regarding ejected material which would seem to indicated D50 over a certain size is not liquefiable. Is there a definitive reference or references regarding particle size vis a vi liquifaction?
