gds instruments rock mechanics product catalogue · pdf filegds instruments rock mechanics...

GDS Instruments Rock Mechanics Product Catalogue 2014

World leaders in the manufacture of laboratory systems for soil & rock

2

About GDS Instruments

GDS Instruments (Geotechnical Digital Systems, or simply GDS) designs, develops and manufactures material testing machines and software used for the computer-controlled testing of soils and rocks. This technology is used to evaluate the mechanical properties that are key in geotechnical and earthquake engineering design.

Since being founded in 1979, it is estimated that GDS products have been used to help achieve over 1000 PhD’s. As well as being the first choice for academic research, GDS products have been used in many world renowned commercial laboratories for projects including the Three Gorges Dam in China, the Millau Viaduct in France, the Vasco da Gama Bridge in Portugal, Terminal Five at Heathrow and the new Crossrail link in London.

GDS employs over 35 permanent members of staff at their offices in Hook, Hampshire, UK, as well as working with a network of agents spanning 40 countries. GDS UK based staff include 3 PhD’s, 8 qualified civil / geotechnical engineers, 4 software designers, 4 hardware designers and 5 electrical/electronics specialists, allowing GDS the capability to design, build, test and ship their products directly to the customer.

In 2011 GDS were awarded the prestigious Queens Award for “Enterprise in International Trade”.

Values at GDS

GDS believes in providing the best equipment for the job combined with first class support from engineers who understand the equipment and applications. GDS design and develop all their products in-house using their team of geotechnical engineers, software designers, hardware designers (3D CAD) and electrical/electronics designers and specialists. This allows GDS to have complete control of the design, build, test and shipping process. GDS’ in-house expertise allows the capability to design bespoke systems (hardware, electronics and software), which forms a significant part of GDS’ reputation.

GDSLAB software supports every GDS computer controlled device manufactured since 1979, as well as devices from other manufacturers that have long since been made obsolete by them. This forms part of our unique commitment to long term customer support.

When you receive training from or ask a technical question of GDS, your reply will be from, or via a geotechnical engineer. This is our philosophy for ensuring the best service possible. Great service = repeat customers and we have many repeat customers.

GDS production and manufacturing is carried out in the UK to strict quality standards and our management systems are ISO9001 accredited.

GDS Customers

GDS work closely with Research and Commercial companies. Utilising our network of agents has allowed GDS to work in many countries around the world and become involved with some world renowned organisations / institutes on a variety of different projects.

Please Note: Due to continued developments, specifications of products within this brochure may change.


www.gdsinstruments.com

Introduction to GDS Rock Testing Apparatus

GDS have manufactured high pressure automated triaxial testing systems for rock mechanics for over 20 years, with systems installed at leading research and commercial institutes around the world. The High Pressure Triaxial Automated System (HPTAS) is a load frame based triaxial testing system for accurate testing of rock samples. It is GDS’ most flexible system whereby components can be chosen by the user to meet their exact requirements. An image of the 500kN VIS load frame is shown below.

The HPTAS is made up 3 fundamental components:

1) High stiffness, high capacity load frames up to 2000kN.2) Pressure control for cell and back pressure up to 150MPa.3) Test cell (either a high pressure triaxial cell or a Hoek cell).

GDS have a wide range of high pressure triaxial cells, either with or without a balanced ram to complement their rock testing apparatus. Traditional Passive Triaxial Cells up to 64MPa with balanced ram and 100MPa without Balanced Ram.

Alongside GDS’ range of high pressure rock triaxial testing systems is the GDS High Pressure Back Pressure Shearbox (HPBPS).The HPBPS is a high pressure version of the GDS back pressured shearbox, which also has the unique feature of being able to perform direct shear tests with precise back pressure control for the realistic modelling of slope failure. The device can load the sample to 100kN axially and 100kN in shear whilst also being capable of maintaining up to 10MPa back pressure.

HPBPS - High pressure back pressured shearbox.

500kN VIS Load Frame.



Key Features: Benefits to the User:

System calibration: The GDSVIS is calibrated to provide precise data on the load-deformation relationship of the entire load application and load measuring system.

Load frame stiffness:

GDSVIS load frames are extremely stiff and designed principally for rock testing to allow minimum backlash at the point of sample shearing (other, less stiff load frames do not give good results at this critical point in the test due to the stretch of the load frame under high load).

4 column rigidity: The load frame has been built with 4 columns for extra strength and rigidity and can hold a cell size with a 700mm outer cell diameter.

Feedback control: The GDSVIS comes with feedback control and continuous displays of axial load and platen displacement.

USB computer interface: May be used stand-alone using the keypad supplied or under computer control.

Tests that can be Performed: Axial compression load, axial displacement, axial extension load and cyclic (slow speed) load or displacement.

Upgrade Options:Extra tall columns allow heavy cell tops to be raised from their boxes using the automatic cross beam raising and lowering mechanism, making sample preparation quick and easy for a single operator.

Hydraulic column locks replace the standard torque wrench tightened bolts, allowing the user to quickly and easily exert clamping forces when adjusting the height of the frame.

Technical Specification:

Computer Interface: USBDisplacement Accuracy: 0.05% of full rangeDisplacement Range (mm): 100Load Range (kN): 500Data Acquisition: 16 Bit 4 ChannelResolution of Measurement and Control: <0.1% full range, displacement = 0.1micrometre

Overview: The 500kN Virtual Infinite Stiffness loading system (VIS500) is the premier load frame in the GDS VIS range. VIS stands for virtual infinite stiffness, it allows the axial loading system to operate as though it has infinite stiffness (zero system compliance). This type of frame is exclusive to GDS.

The 500kN version of the VIS has the added advantage that the beam lift can be used to lift the cell top on/off the cell base (extra long columns as an option) as well as options for hydraulic clamps to hold the beam in place. The 500kN VIS is a superstiff version of a standard GDSVIS to minimise system compliance even further.

500kN Load Frame (VIS500)




To increase efficiency and to reduce whole life costs the actuator is powered by a 200cc / 64MPa GDS Advanced pressure controller:

This efficiency means that the full load of the frame can be achieved by drawing less than 1000 Watts (1kW) from mains electricity in place of a hydraulic power pack which can draw up to 50kW. Control is carried out by a GDS advanced pressure controller and as such is very stable and accurate. No special requirements are needed to host or service a powerpack or to protect system users from noise generated by a powerpack.

The static frame uses low pressure compressed air on the reverse side of the actuator to raise the actuator post compression:

This allows a simple manual regulator to be set with a small pressure in the upper chamber of the actuator. This innovation allows lower stress testing to be carried out more efficiently and more accurately without the cost implications of using a second pressure controller for the upper chamber of the actuator. Once the regulator is set it can then be left unattended for all tests, so long as a supply of clean, dry compressed air is available at a pressure greater than 0.5MPa (5Bar).

Ideal for creep and relaxation testing: Ideal for use where displacements are very small and loads needs to be very stable and well controlled.

Infinite Volume Controller option: For tests where continuous displacement is required to amplitudes greater than 5mm.

Tests that can be Performed:Load control and axial displacement control.

Upgrade Options:Triaxial, additional 64MPa controller and Infinite Volume Controller for tests where continuous displacement is required, additional data acquisition channels, an extensive range of Triaxial and Hoek cells are available to a complete triaxial testing solution for rocks and temperature control (up to 200 Degrees C).


Actuators: HydraulicDimensions (mm): Frame footprint 700 x 600 x 1850Displacement Range (mm): 100Load Range (kN): 1000 / 2000Weight (kg): 1725

Overview: The GDS Static Loadframes are actuated from the base by a hydraulic actuator at loads up to 2000kN. To increase efficiency and to reduce whole life costs the actuator is powered by a 200cc / 64MPa GDS advanced pressure controller. This efficiency means that the full load of the frame, can be achieved by drawing less than 1000 Watts from mains electricity in place of a hydraulic power pack which could draw up to 50kW, to achieve similar loads.

1000kN (1MN) / 2000kN (2MN) Static Compression Loadframes (HLF1000-S), (HLF2000-S)



Key Features: Benefits to the User:The HLF1000-H has closed loop-feedback control of force and position as standard:

This allows the frame to be used for many different test types from soil to rock mechanics and other material test applications where precise control of axial force and displacement are required in a very stiff reaction frame (2GN/mm).

Compact design: Reduces the laboratory floor space required, only 2430mm x 750mm x 700mm.

Hydraulic power: Hydraulic power is derived from a separate powerpack that can be sited up to 15m from the loadframe.

ELDCS control system:This loadframe is controlled by the ELDCS control system which, has 4 channels of high speed data acquisition built in and is connected to the PC via the USB bus.

Closed loop-feedback control of force and position as standard:

The loadframes have closed loop-feedback control of force and position as standard. This allows the frame to be used for many different test types from soil to rock mechanics and other material test applications where precise control of axial force and displacement are required in a very stiff reaction frame.

Low friction, bidirectional actuator: Full system load is available in compression and tension.

Tests that can be Performed:Axial compression, axial extension, load control (Static), load control (Dynamic), displacement control (Static) and displacement control (Dynamic).

Upgrade Options:An extensive range of Triaxial and Hoek cells are available to a complete triaxial testing solution for rocks and Temperature control (up to 200 Degrees C).


Actuators: HydraulicDimensions: Dependant on chosen specificationsDisplacement Accuracy: 0.2% FRODisplacement Range (mm): 100Load Range (kN): 1000Max Loading Frequency (Hz): 2.5Data Acquisition: 4 Channel 16 Bit

Overview: The 1000kN Dynamic Loadframe (HLF1000-H)is a servo-hydraulic system that has been designed to be a compact and effective addition to a soil and rock testing laboratory.

Hydraulic power is derived from a separate powerpack that can be sited up to 15m from the loadframe.

Two versions of the 1MN loadframe are available:• 4 Column Moveable Head - where different sized test

cells are to be used.• Fixed Heads.

1000kN Dynamic Load Frame with Hydraulic Actuator (HLF1000-H)



What is a Balanced Ram?The balanced ram is a system that compensates for the up thrust on the ram exerted by the cell pressure. Our system utilises a secondary chamber around the ram that balances the pressure in the cell against a second piston seal such that the pressure load is not exerted onto the loadframe.

This system usually means that a smaller range loadframe can be used to achieve the same deviator loadings on the sample. For example if a cell has a 50mm diameter ram and a cell pressure of 32MPa the up thrust would be approximately 63kN on the frame. This would have to be deducted from the maximum achievable deviator loading that a given frame can apply. With a balanced ram, the full load frame capacity may be used to apply axial force on the sample as there is zero ram upthrust. In addition, a balanced ram within a high pressure passive cell eliminates disturbance to constant cell pressure during axial loading.


Large pressure range: GDS triaxial cells are available from 4-100MPa, allowing user to choose the ideal cell for their range of testing needs.

Large variety of sample sizes: GDS range of cells can hold samples up to 100mm at a variety of different pressures.

3rd party frames:GDS Triaxial cells can be supplied as part of a complete system or for use in pre-existing 3rd party loadframes. Please contact GDS with the make and model of existing frame for fit information.

Temperature control: Versions of some cells are available for testing samples at elevated temperatures up to 1500C.

Stainless steel design:All GDS high pressure cells are made from stainless steel and as such they will give many years of use without tarnishing or needing to be replaced due to corrosion.

Balanced ram: GDS high pressure triaxial cells are available with or without balanced ram. See difference below.


Pressure Range (MPa):

High Pressure Passive cells with balanced ram; max sample size/pressure range: 54mm/64MPa, 100mm/64MPa.High Pressure (>5MPa) Passive cells without balanced ram; max sample size /pressure range: 50mm/14MPa, 50mm/64MPa, 70mm/100MPa, 10mm/14MPa, 10mm/20MPa

Overview: GDS produce cells for 20 to 100mm and from 4 to 100MPa to satisfy the complex range of tests required by today’s modern geotechnical laboratories. Cells are available with or without balanced ram.

High Pressure Triaxial Cells (CELLS-HP)


2


Realistic slope stability conditions: Conditions can be applied by accurately controlling the normal force, shear force and back pressure.

Highly accurate displacement measurement: For very small yet long term creep movements to be measured.

Direct shear testing: Allow direct shear tests to be performed under closely controlled conditions in terms of axial load and back pressure.

10MPa stainless steel cell: For back pressure control and pore pressure measurement.Provide accurate results whilst working at high loads: Up to 100kN axial and shear load.

Tests that can be Performed:Monotonic shear, cyclic (slow speed) shear and creep tests (under load or displacement control).

Upgrade Options:Small strain shear LVDT system.


Computer Interface: USBData Acquisition: 16 bit

Load Range (kN): 100 Axial100 Shear

Operating Frequency (Hz): Quasi Static (capable of slow speed cyclic testing, periods around 5 minutes).Pressure Range (MPa): 10Sample Sizes (mm): 50 diameter or 100 diameter cylindrical, 50 high

Overview: The High Pressure Back Pressure Shearbox (HPBPS) is a high pressure, high load version of GDS standard back pressure shearbox and is able to perform direct shear tests with precise back pressure control, for the direct control and measurement of realistic slope failure.

The device can load the sample to 100kN axially and in shear whilst also being capable of applying up to 10MPa back pressure.

High Pressure Back Pressure Shearbox (HPBPS)



Customer Testimonials

Read a sample of our customers feedback below.

“I would like to thank you personally for your outstanding support, control, demonstration and training of the ELDYN. Working more than 12 hours per day with you and with Orestis (NEOTEK) we learnt a lot and we are all grateful for your efforts and dedications. It truly made a difference! Thank you very much!” “I have been dealing with GDS Instruments for more than 10 years in the UK and Canada. During my dealings with the company they have been highly professional, providing excellent service and products. We have compared the products and service from a number of other vendors as part of our purchasing procedures, using a range of metrics and GDS consistently out perform their competitors. Their maintenance procedures and after sales service are also excellent. I have no hesitation in recommending GDS Instruments for soil testing instrumentation and apparatus.”

“I have had an exceptional experience with GDS. I was hired in 2003 to bring a geotechnical lab back to life after 5 years of inactivity. Through the unbelievable technical support and because of the quality of GDS’s products the original advanced triaxial system purchased in 1989 is working without a problem. I continue to use GDS and have confidence that their products will provide me with high quality data. The service and products provided by GDS are simply second to none.”

“Your technical support has been exceptional, rapid, detailed, and on target, even for a small customer like me. Please feel free to pass along my contact information to whomever you wish.” “I have used GDS’s LVDT (Local Strain Transducers) system to study Chicago clay samples for the past three years at Northwestern. The LVDT system allowed me to measure the strains directly on my test specimen. By using it, I could minimize uncertainties in interpretation from apparatus compliance, tilting of the specimen and the imperfect platen-sample bedding. Furthermore, the accuracy, precision and resolution level of the device are one of the major factors in my successful research. I can recommend GDS’ LVDT’s as a reliable internal measurement device.

“I must say that I have had an excellent experience with GDS. All of your staff have been extremely helpful and responsive to all of my requests. When I originally purchased the Bender Element accessories, the GDS staff did an excellent job in providing shop drawings and manuals to be used in modifying my existing triaxial system. I will certainly be using GDS again in the future. Thank you for your past assistance.”

“My first purchase was based on reference from a colleague; since then I have continued to purchase from GDS because, mainly, of the attention to detail and flexibility in system design, as well as tailored customer service for hardware and software.”

“I wish all instrument companies I dealt with were as responsive and capable as GDS.”

“I am very happy to provide a reference. You guys are *stars*! I am a minor GDS customer, but you have always been extremely supportive, knowledgeable, and speedy in helping me with questions.”

“FYI - we are currently testing more samples in our GDS-based system, this will be the 5th student to do a thesis using your equipment in my lab.” “Thanks very much for the information. The support and service from GDS is excellent and very much appreciated.”

“I would very much like to stay in touch as I am sure we can do business again. I am always impressed with the professionalism of the team at GDS”.

“I would like to thank you for the outstanding service regarding to the pressure-volume controller.”

“I will happily confirm the quality and function of the equipment, as well as prompt and very professional support!”

“Thank you very much, and I am certainly pleased to be doing business with GDS Instruments.”

GDS InstrumentsUnit 32 Murrell Green Business Park,London Road, Hook,Hampshire, UK, RG27 9GR.

Tel: +44 (0)1256 382450Fax: +44 (0)1256 382451Email: [email protected]: www.gdsinstruments.com

gds instruments rock mechanics product catalogue · pdf filegds instruments rock mechanics...

Documents