Types incorporating pre caste concrete unite Drilled-in tubes Minipiles 1.5 Aide to classification of piles Figure 1-8.for a quick understanding of pile classification,a hierarchical representation of pile types can be used.Also advantages and disadvantages of different pile materials is given in section 1.6. Types incorporating pre caste concrete unite Drilled-in tubes Mini piles 1.5 Aide to classification of piles Figure 1-8. for a quick understanding of pile classification, a hierarchical representation of pile types can be used. Also advantages and disadvantages of different pile materials is given in section 1.6