ISO 22476-15:2016 pdf free
ISO 22476-15:2016 pdf free.Geotechnical investigation and testing一Field testing
Drilling parareters can be considered as being in one of three categories.
一Parameters imposed by the method (type of drilling tool and diameter, nature of the fluid medium,limits of machine performance and injec tion system) and unmanaged scalable parameters (tools wear, changes in the composition of the fluid).
一Parameters set by the operator (po down-thrust, VR drill head rotational speed, Q flushing medium circulation rate in the case of an incompressible or water based drilling fluid, pl injection pressure in the case of a compressible air based fuid),
一Parameters depending on the response of the ground (VA penetration rate, CR torque, PI injection pressure in the case of an incompressible or water based fluid, Q1 flushing medium circulation rate in the case of a compressible air-based fluid),
These parameters may be measured directly or calculated using calibration relations. Further compound parameters may be derived by combining a number of drilling pararneters (see A.2) Drilling machines with appropriate stability, power and equipment such as drilling rods and bits shall be selected in order to achieve the required depth and stability of the borehole. The drilling equipment shall be of the appropriate size and type in order to produce the required quality of MWD test. The drilling rig and equipment shall allow all drilling functions to be adjusted accurately.
The drill rig shall be chosen based on the project objectives with sufficient capacity to penetrate the various geologic layers and equipped with the appropriate drilling tools.
Drill head and feed mechanism shall be hydraulcally operated to allow drilling parameter monitoring.
Only top hammer drilling shall be used. The equipment shall be loaded or anchored to limit movements of the drilling machine relative to ground level while the penetration occurs.
Prior to each use, the straightness of rods shall be checked visually. The deviation of the linearity of the rods shall not exceed 5 mm from the centreline for 3 m long rod. The straightness of the push rods shall be determined at regular intervals.
The drilling tool used for MWD method shall be drill bit type acting in rotary or rotary percussion drilling. The use for other drilling technique shall be avoided.ISO 22476-15 pdf free.
