If the groundwater level is way too deep from the ground surface (-50 metres), for clay soils, can undrained parametres be used? (lets assume that one wants to do an undrained analysis)
Since there is no water, is the assumption that the soil will behave in a drained manner correct?
#Geotechnical engineering #soil strength parametres
Well,
Quoting from the link;
http://geotechsimulation.com/2018/05/18/soil-drained-undrained-behavior/
Undrained shear strength is not a fundamental soil parameter. It generally varies over depth as a function of in situ confining stress at a given depth.
Note that larger confining stress reduces the void ratio over the historical time. By the decrease of void ratio, undrained shear strength increases.
This is why there are several correlations available for the determination of Su from the initial void ratio, water content/plasticity index, and historical effective confining pressure.
Regards
Please Ref J. Guerif 1994. Effect of compaction on soil strength parameters , Deve. in Agri.,Engineering volume 11, page 191-214
Generally, the well drained conditoion is depends upon the soil types,its depth, hard pan etc. and that decide the drainage coefficient.