Soil Simple Shear Test
GCTS offers two solutions for Simple Shear testing: the SSH-25 and the SSH-100. Both systems feature closed-loop digital servo-control of the shear and normal loads for test automation. Stresses or strains for both the shear and normal actuators can be prescribed to automatically perform conventional simple shear tests as well as cycle dynamic tests, such as liquefaction or cyclic strength. A high-precision vertical deformation sensor is included to perform liquefaction tests on dry sands by specifying a zero-vertical deformation during cyclic shear loads. The electro-hydraulic loading system for both the normal and shear load actuators can apply or maintain the prescribed loads or deformations with a very small compliance.
The SSH-25 is mounted on a convenient cart with casters that not only supports the apparatus, but also houses the hydraulics inside. The wireless interface and standard power allows the user to place this system anywhere there is a power source. This system can also be equipped to perform static or dynamic direct shear tests.
The design of the SSH-100 is based on our external cell wall triaxial system. The apparatus has a fixed top and a sliding bottom base mounted on special linear bearings to help with specimen loading and unloading. The system also has a stiff internal support to minimize lateral compliance of the top cap. One of the main advantages of the GCTS Simple Shear Testing System is that the apparatus does not require a reinforced membrane, as lateral support is provided via the confining pressure, which can be servo-controlled. This means that consolidation can be done at K-values other than K0. This device does include thin, Teflon-coated rings to externally reinforce the standard latex membranes to ensure K0 consolidation. The SSH-100 is capable of testing 100 mm (4 in.) and 71 mm (2.8 in.) diameter specimens. Because the internal lateral support is provided by the confining pressure, specimen of different heights can be tested. This means that the system can be used to test either simple shear or triaxial test specimens with heights up to 2.5 times their diameter.
SSH-25
HIGHLIGHTS
- Dynamic and static simple shear apparatus capable of applying cyclic loads up to 5 Hz (20 mm/sec max. velocity)
- Closed-loop servo-control of double acting (push/pull) 18 kN shear load actuator with ±25 mm. stroke & 18 kN normal load capacity with 50 mm. stroke
- 100 mm. (4″) diameter standard specimen size. Optional 70 mm. (2.8”) diameter specimen platens and Ko rings available
- Normal load reaction support mounted on sliding bearings to minimize horizontal friction
- Software for automatic performance of simple shear tests with real time graphical display of test progress
- Load frame, signal conditioning unit, and hydraulic pump mounted to a moveable cart
- Optional accessories and software to perform direct shear tests
SSH-100
HIGHLIGHTS
- Dynamic and static simple shear apparatus capable of applying cyclic loads up to 30 Hz
- Digital servo control of shear and normal loads or displacements
- Servo control of the confining pressure
- Acrylic cell capable of 1,000 kPa (150 psi) lateral confining pressure (2,000 kPa option available)
- 25 kN normal and shear load capacity
- Interchangeable platens for specimens up to 100 mm in diameter
- Lateral support of top cap to minimize rotation compliance & sliding base mounted on preloaded linear bearings
- Software for automatic performance of simple shear and triaxial tests (static and dynamic) with real-time graphical display of test progress
- Automatic tilt mechanism for fast and easy specimen installation
- Optional platens for triaxial testing
- Optional ultrasonic platens for P and S wave measurement
- Optional HAEV platens for unsaturated soil testing
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