primary vs secondary consolidation

[ketanco]

Hello

On 6 minute solutions for geo, problem 42. why does it say it is normally consolidated and take only primary consolidation into account and not secondary consolidation as well?

it is basically a question that has sand and below the sand clay. you excavate some of the sand and refill and apply surcharge. it asks for the clay settlement underneath.

Thanks

 

[MikeMcC215]

Secondary consolidation takes place over very long periods of time(years), if you are surcharge loading for ground improvement you most likely will only be able to achieve some of primary consolidation and probably zero secondary consolidation in this time frame. Thats the way you need to think to pass this test.