Strain recovery by stress relief through overcoring is accomplished by using either CSIRO or USBM gauge. This elastic strain recovery is measured. The stresses are calculated after the determination of elastic properties of overcored materials. Over coring using CSIRO cell gives the primary stresses directly where as using USMB gauge over coring has to be done in three mutually perpendicular bore holes to get the primary stresses. There are 12 strain guages in CSIRO cell and 4 strain guages in USBM gauge.

These equipments can be used for finding out the depth of subsurface layers, depth to bedrock and relative quality of rock mass. The subsurface can be better lineated quickly and economically.

A continuous recording of variations in parameters like borehole diameter, electrical resistivity, self potential; temperature, gamma ray logging etc. can be obtained with the help of this instrument. The profile indicates possible location of weak zones in the formations, which can be investigated thoroughly.

TV borehole camera is a black and white camera which can be lowered inside an Nx size dry or water filled bore hole for obtaining the geological information of the bore hole walls. Two types of attachment, namely axial and diametrical, are available, and are alternatively used. While lowering the camera and viewing the bore hole walls on the monitor, video recording is also done. An audio commentary, wherever necessary can be added later on or simultaneously.

This equipment facilitates testing for determination of the deformation modulus up to a depth of 45 m in Nx size bore hole. The two probes of Goodman Jack are available. The one with a capacity of 35 Mpa is employed for estimating the deformability characteristics of soft rock, whereas the other one with capacity of 70 Mpa is used in hard rocks. The pressure applied is measured at the surface and the corresponding deformation at the location of the probe in a plane across the bore hole direction are measured.

The equipment permits the determination of deformability characteristics of rock mass using the method suggested by the International Society of Rock Mechanics (ISRM). It consists of hydraulic pumps, two flat jacks, extensometers, pressure guages and assembly required for simultaneous loading of two areas across the driff. Deformations of rock mass are measured with the help of extensometers which are positioned at varying depths inside a hole. The test can be conducted with incremental and cyclic loading cycles. Creep characteristics of rock mass can also be ascertained.

The equipment consists of flat jacks, hydraulic pumps and jacks, extensometers, readout unit and assembly for applying the normal load. Large diameter diamond saws can be used for carving rock blocks for conducting in-situ shear tests. Block of 70cms X 70 cms X 35 cms can be sheared under different normal loads to obtain peak and residual shear strength parameters. These parameters are essentially required for the stability analysis of rock slopes and strength characterisation of dam foudnations.

This equipment is a dilatometer with a capacity of 100 kg/sq.cm and used to find the deformation characteristics of soft rocks. Water is used for developing the pressure instead of commonly used hydraulic oil. The chart has been provided to correlate the applied pressure and the corresponding thickness of rubber sleeve of dilatometer.

This saw is utlized to cut the rock blocks accurately without disturbing the rock mass.

A portable electrical drilling machine with 17.5 HP, motor procured under one of the UNDP assisted projects is used for drilling inside drifts and tunnels for the purposes of testing and instrumentation. The machine permits the use of special attachments required for stress measurements by overcoming (USMB gauge) technique.

Hydraulic fracturing equipment is used for the determination of in-situ-stresses in deep bore holdes. Stresses can be measured upto a depth of 300 m in Nx hole and upto 30m in Ex size holdes. The orientation of the crack is measured with digital compass and stress at the point of testing is measured using pressure transducer. The equipment comprises of bore hole tools two sets of packers, two flow pumps, injection fluid and impression packer.

The Research Station is equipped with necessary instruments like Tape Extensometer, Bore hole Extensometer, Piezometers, Inclinometer for undertaking the monitoring of structures during or post construction. The field observations can be supplemented by laboratory testing and computer aided analyses, if required. The underground instrumentation helps In understanding the state of the subsurface formations.

Borehole extensometers are used to measure rock movements which may take place as a result of surface and underground excavations, foundation loading and movement of natural slopes. The borehole extensometer consists of a single rod or wire extending between the anchor and the reference head is called Single Position Borehole Extensometer. Extensometers with more than two rods or wire (upto a maximum of about 8) are termed as Multiple Position Borehole Extensometers.
The instrument is grouted in the borehole leaving reference head on the wall surface of the structure. Readings are periodically taken by the censor on all the points in the reference head and difference of

The point load test is primarily an index test for the strength classification of rock materials. The apparatus is light and portable and hence can be used in the field as well as in the laboratory. The testing machine consists of the systems for measuring the load required to break the specimen and for measuring the distance between the two platen contact points, which can be varied from 15 to 100 mm. Spherically truncated, conical platens made of hardened steel are employed. The load measuring system is provided with the facility for recording load at failure.

The apparatus is used to assess the resistance offered by a rock sample to weakening and disintegration when subjected to two standard cycles of drying and wetting. The apparatus consists of two drums of 2mm standard mesh cylinder of length 100mm and diameter 140mm, with removable lids. The drums can withstand a temperature of 105^o C. Both the drums are fixed to either side of a motor drive, capable of rotating the drum at a speed of 20 r.p.m. in the trough, containing water or any other slaking fluid. The drums are filled with the slaking fluid to a level of 20mm below the drum axis.

This test is intended to evaluate the swelling characteristics. One way is to measure the pressure necessary to constrain an undisturbed rock specimen at constant volume when it is immersed in water. The other is to record the swelling over a period of time for a given load or no load condition. The apparatus consists of a standard GEONOR 1000 kpa loading frame with liver arm ratio 1:10 suitably modified. A load gauge is introduced into the vertical dead- weight rod which again is secured to a screw

The Universal Panel Meter (UPM-40) is a microprocessor controlled multipoint measuring unit with the main application in the field of the experimental stress analysis using strain gauges and in multi-point measurements with strain gauge transducers. Upto 40 measurement points can be @ connected to the instrument which can be scanned either manually or automatically in a sequence. The measured value is displayed on the front panel LED indicators. The in-built printer gives the detailed test data. UPM-40 can be controlled by a PC through interfaces. This equipment is mainly employed, along with Universal Testing Machine for the evaluation of deformability characteristics of rock.

The Hoek triaxial cell comprises of a steel body and two steel end-caps which are screwed to the body of the cell. The cell- body has two self-sealing couplings; one for connecting to the hydraulic pressure system and the other for de-airing the cell chamber and for the attachment of' pressure measurement device. The polyurethene specimen jacket is fitted inside the cell to transmit stress. Hoak's cell of different sizes (Nx, Bx etc.) are available.

This test is intended to measure the resistance offered by aggregates to surface wear by abrasion. The equipment consists of a flat circular cast iron grading lap of 60 cm in diameter, which rotates in a horizontal plane at a speed of 28 to 30 revolutions per minute.
Two conical hoppers mounted on a bracket feed abrasive material generally sand continuously on the lap. There is an arrangement to regulate the flow of sand from the hoppers.
Under the rotating disc, there is a provision and an outlet to facilitate the recovery of sand.
Two brackets have been provided diametrically opposite to each other for holding the specimens.

This instrument measures accurately and rapidly the surface profiles including roughness and variance of rock surface. A stylus fitted with the instrument is motor driven in forward and backward direction over the surface. The signal is picked up with high precision, amplified by the amplifier and is recorded on a X-Y recorder. An alarm buzzer operates in case of vertical overloading of the stylus and a red lamp glows when the stylus is caught by the workpiece. The instrument is also provided with a manual control for efficient measurement. Seven tracing speds are provided to enable selection of the optimum measuring speed.

The Sonic Viewer generates ultrasonic waves and measures their travel time. It has a Cathode Ray Tube (CRT) display and a small recorder. The signal enhancement feature allows to develop high quality wave forms even from faint signals. The two channel memory is convenient for simultaneous comparison of wave forms. The instrument has a standard video signal which can be used with a video recorder. The frequency range is 1 to 40KHz. and 1 to 80;

KHz. The Sonic Viewer operates at 12 V DC supply.
Compression Wave Transducers and Shear Wave Transducers are employed to transmit/receive compression waves and shear waves respectively. The transmitter and receiver are interchangeable. Being a non-destructive technique of obtaining information about samples in different states. i.e. dry and saturated, it is used for the determination of P&S wave velocities of the rock samples.

The Universal Testing Machine (UTM) is a motor driven hydraulic loading machine having maximum capacity of 500 kN. Two control valves are used for loading and unloading. The machine is provided with five load ranges; and range can be selected by a capacity change wheel centrally positioned. The load can be read on a circular chart which is also provided with a maximum load pointer. The electrical overload trip operates on all ranges. The load pacer enables to set the loading rate for one chart sweep. A drum recorder records the loading and unloading. The facility for installing different types of attachment exists and hence tests in uniaxial compression, uniaxial tension, flexure, indirect tension etc. can be performed.

Direct Shear Apparatus is used to evaluate the shear strength parameters of the samples with pre-defined failure planes. Being light in weight and portable, the samples can be tested in the laboratory and field both. Small samples, with approximately five sq.cm. plan area are sheared along the pre-existing discontinuity or weak plane.The test specimen is prepared by casting the rock samples in plaster of paris in two halves with 1 cm gap between the two halves.
At different normal pressures applied with a pump the upper half of the metallic sample holder containing the specimen is sheared

by applying shear load through another pump. The normal load, shear load, vertical displacement and shear displacement are recorded employing appropriate gauges.

3 D Crack Monitor has been designed, developed and fabricated in the CSMRS workshop. This instrument is being used for monitoring the relative deformation of rock mass simultaneously in three mutually perpendicular directions across a crack. This instrument is extensively used for long term monitoring the crack deformation in the underground cavern of power house of Sardar Sarovar Project, Gujarat.