how do you compact soils to 95% max Proctor density?

[hippo11]

You see this in geotech reports all the time...but how does the contractor actually do this compaction in the field? And how does he physically verify that he has compacted enough?

thanks

 

[GeoPaveTraffic]

As for how it is done by the contractor: about any way he wants. If the area is large then a sheeps foot or smooth drum roller is usually the best bet. If the area is small then a a "Jumping Jack" or sled compactor is usurally used. Other methods include using truck or equipment traffic.

Dentity is typically verified by an independent testing company usin drive tubes or nucular gauges.

 

[SlideRuleEra]

Controlling the soil moisture content at the time that compaction takes place is important, too. In dry conditions this means using a water truck to apply water. In wet conditions, a disk harrow may be used to break up the soil and promote drying.

http://www.SlideRuleEra.net

http://www.VacuumTubeEra.net

 

[BigH]

hippo11 - why not pick up a introductory soils book and read the sections on compaction. Then you will have a better understanding of how the contractor achieves the required level of relative compaction (steel drum compactors, jumping jacks, tag-alongs, vibrating plates) and how this is verified in the field (nuclear density meters, rubber ballons, sand cones, drive tube, heel test, etc.) For example you can look in Fang's Foundation Engineering Handbook's chapter by Hilf (extensive and detailed).