Prepared by :
Siti Aisyah Binti Ghazali

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INTRODUCTION
• Boring : soft and uncemented ground which is normally close to the ground surface.
• Type : Auger boring, wash boring, rotary drilling and percussion drilling
• Focused on : rotary drilling.
• Theoretical : rotary action + force to grind soil or rock= hole. Drilling requires a combination of a number of element (Heinz, 1989).
CASE STUDY
• Proposed Petronas Petrol Station at Gambang, Pahang Darul Makmur.
• Rotary drilling +water (flushing medium ) = exploratory boreholes.
Objective boring test
• To observe the subsoil strata and soil grouping .
• To determine the depth and thickness of the soil composition.
PROCEDURE
• Drilled is rotated by applying force.
• The bit is fastened and rotated by a drill string, composed drill pipe to produce a hole.
• Lifted the cuttings from the hole by:
i. circulated down drilling fluid continuously inside the drill string through water courses or nozzles in the bit.
ii. upward in annular space between the drill pipe and bore hole.
Divert the returning fluid at the surface.
Lastly, mud is picked up by the pump suction and repeat the cycle.
Hvorslev (1949) suggested a number of general rules which remain applicable:
• founded on clay and other materials : the borings should penetrate the compressible strata or be extended to such a depth.
• very heavy loads or seepage : stopped boring test when exceptional bearing capacity and stiffness. If not fulfilled, borings must extended until it has been established that the strong strata .
• founded on rock : must verified bedrock and not boulders .Eg: extend one or more borings from 10 to 20 ft into solid rock to determine character of the weathered zone of the rock.
ANALYSIS
• Borehole depth
• Physical properties
i. clayey SILT - BH 1.
ii. clayey and sandy SILT –BH 2
• The depth of soil composition