The part of geotechnical engineering, rock mechanics studies the behaviour of rocks under various physical and environmental conditions. In order to prevent any geotechnical failure, rock testing is undertaken. The rock is measured and tested as per the regulations, design specifications and quality standards. This article explains what is rock testing and what tests can be applied using rock testing machine.
What is rock testing?
In rock testing, rocks are measured, and their behaviour under variable physical and environmental conditions is tested. The testing of rock properties is required in case of mining, drillings, tunnels, road cuts, dams, wells and construction projects where the structures are built on rocks.
Following are the different tests which we can perform on rocks using rock testing lab equipment.
Radial or Axial deformation– In all GDS system, we can measure axial deformation using displacement transducer, whereas we can calculate radial deformation by measuring the change of volume to 1mm3 on a back pressure controller.
Consolidation Testing– In this, constant cell, as well as back pressure, is applied to the sample while we monitor the volume change in the sample. In the case of one-dimensional consolidation, the load is applied to the sample’s top contained in a fixed ring.
Constant pressure source– All the GDS controllers are made to use as sources of constant pressure. In order to ensure that desired pressure is being maintained, the stepper motor constantly adjusts itself with the advantage that the volume change will be 1 cubic mm.
Constant rate of loading consolidation– This ensures a controlled level of load during the maintenance of backpressure. If the specified hydraulic gradient in the sample exceeds, there is an option to limit the rate of strain.
Constant rate of strain consolidation – This ensures a controlled level of the load while the backpressure is being maintained. If the specified hydraulic gradient in the sample exceeds, there is an option to limit the rate of strain.
Cyclic loading of sample either strain or load– The repetitive loading of a sample is called cyclic loading. All the GDS systems can apply this loading. All GDS system can perform the load and displacement control. The speed of cyclic loading is based on the performance of the frequency of the system.
Slow cyclic testing– This testing is conducted on all GDS triaxial apparatus using appropriate software modules. The performance of the system determines the speed of the cycle that can be applied. For quasi-static testing, a standard load frame is used with a period of about 5 minutes when it is coupled with data acquisition software and GDSLAB control.
Damping Ratio in Torsion– This ratio indicates how oscillations in a system stop after a disturbance.
These are some of the tests which can be applied using rock testing apparatus. This article was an attempt to explain what is rock testing, why it is done and what tests can be used using the rock testing equipments.