Kneas Bar Testing

[Chadd]

The Kneas Bar was started by a U Penn Engineer named Frank Kneas as I understand circa 1962. I am far from certain on the details but will attest after hundreds of tests in the field, I conformed in is within 10% of high profduction drill rig blow count results with the 130# hammer provided you only test 2 to 3 feet without hand augering or moving vertically down into the test pit as friction, particularly in cohesive soils will artifically increase your N values due to skin friction. for 1 story commercial and 2 story typical residential loads, the Kneas bar is fantastic to obtain fairly accurate ABV and similar datawhen the budget does not allow us to mobilize a drill rig or even a tripod. The problem I see most often is that we depend on tradtional methods and simply accept feild data as it is. Get out on the field and get dirty! Sample the soil, test it, apply common sense to resistance for the proposed bearing loads and then desing the foundation germane to your field testing and guts from what you found. There is no text book that can match common sense and experience!!! My firm has tweaked this devise to have an eight foot extension. The need for an excavator, hand auger, and elbow grease is a must. You then take your results (similar to a drill rig) and compare to your soil strata. Strong soil description experience is a must or obtain samples for your lab.

Chadd Ingram, PE
Ingram Engineering Services, Inc.
West Chester, PA
Chadd@ingram-engineering.com