GDS Bender Element System

Product Code : GDSBES

The GDS Bender Element system enables easy measurement of the maximum shear modulus Gmax of a soil. 

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 other manufacturers. Need advice choosing the right transducer, view our options table here. To download a FREE bender elements analysis tool for you results, click here.

Further Information:

Discover more transducers and load cells equipment for soil testing.

Key features Benefits to the user
USB interface: Plug and play connection easily connected to any modern PC.
Titanium element inserts: Titanium is used for high corrosion resistance and low-weight.
Wide Compatibility: Pedestals and top-caps can be manufactured for 3rd party as well as GDS cells. Our longstanding experience in designing or assisting with upgrades makes upgrading simple.
Standard insert design:
Reduces the cost and makes the bender element a modular device that can be easily fitted into a suitably modified pedestal/top-cap. Should an element be damaged, it is straightforward for the insert to be replaced by the customer.
High speed sampling rates:
User selectable rates from 500kHz to 125MHz provide ample temporal resolution for determining wave speeds.
Multiple gain ranges with auto ranging:
11 User selectable gain ranges from ±1mV up to ±2V allow input adjustment to match the signal level observed. Auto ranging ensures this happens without user inputs.    
Bender Extender Type Elements:
Determining both S & P wave velocities allows additional specimen parameters to be calculated, such as Young’s Modulus, E.
Vertical and horizontal elements are available:
Specimen anisotropy can be studied, with the use of both vertical and horizontal (Hh & Hv) elements on the same sample.
Unsat compatibility:
Bender elements can be fitted to unsat as well as saturated pedestals and topcaps.
Computer Interface


Data Acquisition

Selectable up to 125MHz (125,000,000 samples/second), with simultaneous sampling of both source and received signals.

Pressure Range (MPa)

Up to 3.5MPa. Above 3.5MPa Acoustic Velocity transducers are required for P&S waves.

Sample Sizes

up to 300mm

  • 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.


Tests supported by the GDS Bender Element System, transducers and load cells equipment for soil testing :-

Maximum Shear modulus

Determination of the maximum (i.e., very small strain) shear modulus of a specimen. Please note: Some apparatus may require additional components or software modules to perform certain tests.

Oedometer / Consolidation

Uses a datalogger to take settlement readings from a hanging weight oedometer system.  Alternatively, GDS produces an automated oedometer which completely automates one dimensional consolidation testing.

Standards for the GDS Bender Element System, transducers and load cells equipment for soil testing :-