Hydraulic Load Frames for Soil

Product Code : HLF100, HLF250 & HLF1500

The GDS Hydraulic Load Frames (HLF) are load frame with a hydraulic dynamic actuator mounted on the cross beam. This allows cyclic dynamic axial stress/strain testing to be performed. The frame can be used to perform standard static testing without any modification.

The system is capable of dynamically controlling axial displacement or axial force and can be synchronised with options for a dynamic cell pressure actuator (radial stress).


Key features Benefits to the user
The GDS Hydraulic Loading Frames can be synchronised with a dynamic cell pressure (radial stress): This gives advanced capabilities to perform dynamic stress paths tests and maintain cell pressure during large strain cyclic testing.
Advanced Transducers (Optional):
A number of optional advanced transducers can be added to the standard system to give measurement of local axial strains and mid-plane pore pressures.
The system is capable of both monotonic (static) and dynamic triaxial tests: 
Creates a versatile multi-functioning system, suitable for most types of tests.
Dynamic control of axial displacement or axial force up to 20Hz, sinusoidal waveform:
Direct (dynamic up to 20Hz) closed loop control of axial displacement, axial force and cell pressure (With optional cell pressure controller).
Optional dynamic control of radial stress up to 20Hz, sinusoidal waveform:
The dynamic control of cell pressure means that for those tests where the cell pressure is constant but the axial actuator is moving dynamically, the cell pressure actuator automatically adjusts the volume of oil in the cell to maintain a constant cell pressure. Or it can be used to cycle the cell pressure (especially at high pressure).
Optional interchangeable internal submersible load cells:
Internal load cells are available to accommodate soft to very stiff soils with ranges of 28, 100 and 250kN. The load frame is supplied with an external load cell to match the model maximum load range as standard (optional internal submersible load cell).
Load frame strength: 
GDS load frames are extremely stiff to allow minimum backlash at the point of sample shearing.
Beam lifts (250kN version) and cell lift:
To adjust the beam height requires the user to unbolt the top beam (allowing it to move up and down) then using the auto beam lift, the beam and be positioned further up or down depending on the requirements. This can also be used to lift the triaxial cell tops off (up to 100mm standard triaxial cell).
Axial Force Accuracy

<0.1% of load cell range (i.e. 1N for 10kN load cell)

Axial Force Accuracy

16 bit (i.e. <0.4N for 10kN load cell, <1.5N for 40kN load cell)

Displacement Accuracy

0.05% of full range

Displacement Range

100mm

Displacement Resolution

<3micrometre

Load Range (kN)

100, 250 or 1500kN

Operating Frequency (Hz)

Up to 20Hz for 150kN & 250kN, 5Hz for 1500kN

Sample Sizes

Dependent on test type / cell selection up to 300mm diameter.

Weight Approx (kg)

670, 1280, 7000

  • Bender Element System (Vertical, Horizontal, S and P waves)
  • Hall Effect local Strain
  • LVDT Local Strain
  • Unsaturated Testing