It’s a circular Boiler required to be installed at a Pharmaceutical factory... Yes, the referred operational loading is the dynamic load which will be exerted on the pile cap & subsequently on the Piles. With regards to the type of pile, the soil investigation report based on two bore holes drilled upto 40 feet, state that the strata consists of Silty clay up till 25 feet and from 25 to 40 feet, the strata consists of sand and silt. Based on the results obtained from these bores, the Geotech experts have recommended 26 feet deep piles (without indicating the type of Pile). Based on my site experience, I will certainly recommend combine (skin friction & end bearing piles for this case with more concentration towards end bearing) Please share your experience and recommendations.