Rotary Drilled Boreholes
Boreholes formed by rotary drilling equipment are normally used when rock or hard or ground is anticipated. Rotary techniques are used to drill through rock / solid geology. There are two types or rotary borehole frequently used on ground investigation projects, rotary open holes and rotary cored holes. Rotary open hole holes are drilled where rapid progress is required on projects such as mining investigations when the structural details of the rock is not necessarily important but we are more interested in the presence of voids that could indicate shallow mine workings. Rotary cored holes are drilled when structural details of the underlying rock are required. Generally used in applications such as when a proposed development has heavy loadings, require deep foundations or when the site is underlain by shallow bedrock.