Gautamee can provide rock drilling using down-the-hole hammer (DTHH) methods at pile sizes up to 400 mm diameter. This removes the requirement for chiseling and coring in rock used in rotary bored piling and due to the higher penetration rates of DTHH equipment this ensures a more rapid completion of the project. DTHH piles are used as an alternative to rotary bored piling methods typically when high rock levels or the presence of boulders prohibit the use of standard CFA bored piling. The loading capacity can be significantly higher than CFA given that the piles can founded within sound competent rock.
There are challenges associated with DTHH system. This system is for rock drilling and therefore the system does not deal well with overlaying strata. In such instances overburden systems are required which include the provision of temporary or permanent casings. It is also essential to control the issue of rock chippings and dust by use of water injection in the lines; the provision of shrouding of the hammer and adequate site protective hoarding.