GDS Bender Element System (GDSBES)

The GDS Bender Element System (GDSBES) enables measurement of the maximum shear modulus of a soil at small strains.

The GDS system is unique in that it is a turn-key system that has been designed to make bender element testing reliable and easy to perform.  The GDSBES system can be added as an option to most GDS systems, as well as systems from other manufacturers. To date GDS have installed bender elements in triaxial, consolidation, simple shear, resonant column, core holders and many other systems manufactured by GDS and equipment for other manufacturers.

To read a customer case study on the GDSBES system click here.

To download a FREE bender elements analysis tool for you results, click here.


Download full specification datasheet (PDF) Enquire NOW



  • 2 Mega Samples/Second Data Acquisition.
  • USB interface so the system can be ‘hot swapped’ to any PC in the lab with a USB interface.
  • Titanium element inserts to reduce weight of top-cap.
  • Packaged, ‘turn-key’ control system.
  • Sine, square and user defined wave forms.
  • Pedestals and top-caps can be made for other manufacturers cells as well as GDS cells.
  • Horizontally propagating elements available.
  • Dedicated Software.
  • The GDS Bender elements are bonded into a standard insert. This method of manufacture has 2 advantages: 
    • It makes the bender element insert a modular device that can then be easily fitted into a suitably modified pedestal/top-cap.
    • Should an element fail, it is simple and quick to replace the complete insert.
  • Elements are manufactured to allow S and P-wave testing to be performed (in opposing propagation directions).
  • The length of the bender element that protrudes into the soil has been optimised without compromising the power transmitted by or received to the elements. This is achieved by fixing the element further down inside the insert and then filling the remaining volume with flexible material.  This allows the element to achieve maximum flexure at its tip, whilst only protruding into the sample by a minimum distance. Advantages of this include prolonged life by increased resilience to breakage and easier sample preparation, particularly on very stiff samples where only a small recess for the element is required.
Computer InterfaceUSB
Data Aquisition16 Bit
Sample Sizes50mm

  • Pedestals for unsaturated testing and bender elements (i.e. with bonded high air entry porous disc).
  • Horizontal bender elements.

GDS Bender Element Analysis Tool:

The subjectivity and lack of satisfactory standards for interpreting shear wave travel times across the industry from bender element test data, has led GDS to develop a bender elements analysis tool. The tool allows the rapid, automated analysis of bender element tests to objectively estimate the shear wave travel time.

The analysis tool is available to download from GDS’ website. The aim is to share the software with the geotechnical community and help the progression towards accepted standards for these tests. The purpose of the tool is to create discussion rather than consider this the final word in automated bender element analysis. Click here to download the software.

Similar products