Temporary or permanent casings can be used if the surrounding ground will not withstand this process. Casings are handled by the rig or by cranes, depending on their size and weight.
When large-scale assignments and those liable to flooding from groundwater prevent the use of casing a drilling fluid, such as bentonite, is used.
The advantages of RBP over CFA piling are the depths and diameters achievable. Also, by using casing, an open hole can be formed to great depths. This enables chiseling or coring to form rock sockets, setting unusually long or complex reinforcement cages, or complex pile instrumentation and load cells.
RBPs deeper than 40m are common and recent trends have seen piles that are over 70m deep.