AS 1289.6.4.2:2016 pdf free

AS 1289.6.4.2:2016 pdf free.Methods of testing soils for engineering purposes
Both base pedestal and top cap shall include porous discs in contact with the specimen. The porous discs shall be made of silicon carbide, aluminium oxide, sintered bronze or other materials which are not attacked by soil or soil moisture. The discs shall be sufficiently rigid to withstand the pressures applied without changes in physical properties. The discs shall be sufficiently fine so that soil will not extrude into the pores, but shall be sufficiently coarse so as to have permeability appreciably greater than the soil sample. The coefficient of permeability of the porous discs shall be greater than 10° m/s for clayey materials and greater than 10*+ m/s for silty materials. Filter paper discs may be placed between the soil specimen and the porous discs to prevent intrusion of fine soil particles. Any filter paper so used should be at least as permeable as the porous discs when subjected to the applied deviator stress (a hard high grade filter paper, such as Grade No.54, is recommended).
The base pedestal and top cap shall both be capable of permitting drainage from the ends of the specimen to outside the cell. Suitable valves shall be provided to allow back pressure to be applied and change in volume to be measured from either one or both ends. The hydraulic line from either the base pedestal or the top cap shall be capable of being connected to a pore pressure measurement system and closed off beyond the pore pressure measurement take-off.
Apparatus for measuring the additional axial load on the specimen to an accuracy of 0.5% of the axial load at failure or ±2 N, whichever is the greater. This level of accuracy can best be achieved by the use of a load measuring device within the triaxial cell. If such a device is used it shall be insensitive to non-axial loads and the cell pressure, or capable of correction to allow for any influence of the cell pressure.If an external axial load measuring device is used it is important to ensure that friction between the piston and the sealing bushing does not influence the results. The alignment of the loading ram shall be such that it passes vertically through the bushing and no significant lateral loads are generated by its connection to the loading machine.AS 1289.6.4.2 pdf free download.