Does anyone have ever heard about a driving formula that separately takes into account the end bearing resistance and the skin friction ? In other words, is there a driving formula where the ratio between end bearing and skin friction is explixitly used ?
The theory behind the dynamic formulae makes it impossible to differentiate between shaft and toe resistance in the pile because it assumes the pile to be a rigid mass. This assumption of course is the first of many problems with the dynamic formulae.
Bengt mentioned the "free wave equation programs"; same is available at