Summary
A thorough description of the wave propagation in the pile is given. This theoretical background in wave propagation will enable a qualitative discussion of the force and velocity signals.
In future research the instrumentation of the Driven Cone Penetrometer to measure strain and acceleration during driving will provide a more powerful method for back calculation site specific parameters.
For this project however, the cone used was not instrumented for dynamic measurements. The actual procedure was much simpler but may also give results that are accurate enough to figure out the quake and damping factors.
For this study a Mini Cone penetrometer of 167 mm² in cross section area, was used. The minicone penetrometer was driven into a chamber of soil where confining pressure could be applied, and the blowcount was recorded. Then the minicone was pushed and the static resistance was recorded. The proposed procedure is to plot the measured resistance versus blowcount curve and match it with the TTI computer program also called Microwave, using the measured resistance as input and changing the parameters including quake and damping in order to match the resistance versus blowcount curve.
Related Publications: Briaud, J.-L. and Khalaf, K., “Dynamic Cone Penetrometer Test for Driven Piles,” Deep Foundation Design Based on In Situ Tests, ASCE Convention in Dallas, October 1993.
