Dynamic Compaction

[coneboy]

Greetings

I was wondering if someone could recommend a good text or publication for designing with dynamic compaction. Specifically, I was looking for some case histories or design guidelines for the drop height, weight and spacing.

I am aware of some of the problems such as those associated with silts/clays and excessive pore pressures.

Thanks for the assistance
Coneboy

 

[Qshake]

Check out ASCE's website for publications. I recall having seen a publication either by ASCE or by the Corps of Engineers on the subject of in-situ ground improvement. The website is

http://www.asce.org

 

Cone b',
Dynamic compaction essentially converts the potential energy of the hammer into the compactive force for the soil

The correlation is as follws

WH = D2 i.e D squared, W = weight of hammer, H height of fall and D is depth of influence densification.
There are issues of adjacent facilities etc hence its limited use, to be used with caution in built up area – potential liaibility claims.
hammer weights may be up to 30Tons at heights of +20m

Normally used for cohesionless soils and landfills

The issues are
type of soil in consideration
depth of planned excavation
required bearing capacities
spacing of compacting bulbs,cones
evaluation of other soil improveemnt techniques

It's not widely used in my area though


kay

 

Try Federal highway publications for this topic either in DC or VA. Area code 212/703

 

[Ron]

Contact Hayward-Baker at any of their offices (

http://www.haywardbaker.com).

These guys are very professional and are experts in this technique. I don't mean to be a commercial for anyone, but I have experience with their capability in ground modification (geotechnical remediation or any other moniker you want to attach to fixing poor soil conditions!) as compared to others.

 

[korea]

I too have a problem relating to dynamic compaction in that I have always thought that its use was for the "densification" of relatively fine grained soils. We are receiving a proposal to use it to compact rock fill (overlaying bed rock) in which the particles range up to 1.5 meters in size. Dropping a large and heavy weight onto this fill would undoubtedly have the effect of crushing the surface material but is it the right way to improve this material? I might add that we are only looking for a bearing capacity of 15 tonnes per sq.meter.

 

The best summary of design methodologies for dynamic compaction was written by Robert G. Lukas for the Federal Highway Administration. Two publications were written, the first as a general overview and the second as an outline of the design process.

I am a project manager for TerraSystems, Inc. TerraSystems is a specialty ground improvement contractor located in northern Virginia. Our services include dynamic compaction, wick drain installation, vibrocompaction/stone columns, and rammed aggregate piers. We would be happy to answer questions at 540-882-4130, or you can visit our website at

http://www.terrasystems-inc.com.

Dave Panich
Project Manager
TerraSystems, Inc.

 

[bosy]

Give me your fax # and I'll fax you the cover pages for Lukas' 2 references. I often work with Bob Lukas, and he is my consultant when I design dynamic compaction for sites. I can fax his card too.