csUnsat

Initial Test Setup

Once the Test equipment has been set up (either the Double Wall Cell or Twin Cell based system), csUNSAT enables you to create the required test.

The wizard can then be used to select the Instrument and associated Load and Displacement Transducers being used for the Test from pull-down menus on the Hardware Setup screen.

The Dimensions setup screen will automatically calculate and display the Specimen’s Area, Volume and Bulk Density from the sample data entered by the User.

Similarly, the Moisture setup screen will automatically calculate and display the Specimen’s Moisture, Dry Density, Voids Ratio and Degree of Saturation from the entered data.

Equalisation Stage Setup

Stress equalisation is defined as bringing the mean net stress and the matric suction to predetermined values. This is accomplished by increasing the pore air pressure, pore water pressure and the radial stress.

You enter the required Mean Net Stress, Suction Pressure, Cell Pressure and the period in which to reach these values. The program will automatically ramp the Pore air, Pore water and Cell Pressure controllers to the required values and will maintain them until the stopping conditions are satisfied. Data will be logged at your specified rate.

The Equalisation Stage is normally stopped when the required Net Stress, Suction Pressure and Cell Pressure levels are reached, however you may additionally terminate the Stage depending on Pore Water Volume Change Rate or a Maximum time period.

Consolidation Stage Setup

In Consolidation, the Mean Net Stress is ramped at the specified rate whilst keeping the Cell Pressure constant and the Suction Pressure is kept constant by maintaining the Pore Air Pressure at the input value. Data will be logged at your specified rate and the Consolidation Stage is normally stopped when the required Net Stress and Suction Pressure levels are reached, however you may additionally terminate the Stage depending on a Maximum time period.

Shear Stage Setup

The Shear Stage initially consists of an engage stage whereby the load cell is docked onto the specimen at a specified rate before proceeding with a number of predefined stress stages (Lines).

Each stress stage Line can be set up with your defined Initial Conditions, data logging requirements and Stop Conditions. Lines can be added and deleted using the ‘Add’ and ‘Delete’ buttons.

The Cell Pressure is used to adjust the Mean Net Stress to the required value whilst the Load frame or Hydraulic Ram provides the Deviator Stress control. Values are entered for the final Net Stress and Deviator Stress along with the time in which to achieve them. During this phase, the suction is maintained at the required value by adjusting the Pore water pressure. readings.

You can specify data logging to be at a predefined rate or using a table (such as Square Root of Time or Logarithmic Time).

Each Stress Stage Line is terminated when either the specified Net Stress, Suction Pressure and Deviator Stress Levels are reached, the Axial Strain extends beyond a specified percentage or a maximum time has been exceeded.

Once all the Stress Stages have been completed, you have the option to fail the specimen if required.

Live Test Views

Live Graphical and Table Views

For all stages (Equalisation, Consolidation and Shear (and Failure if selected)) Clisp Studio enables you to monitor the Test progress both graphically and in the form of a table whilst the Test Stage is running. There are Predefined Graphs which plot using the usual axes and predefined Tables which display the most commonly measured parameters and expected results as the Test progresses, but you can also customize the desired Graphs and Tables from the list of variables that are relevant to that particular stage.

Results 

Clisp Studio csUnsat produces results views, graphs and tables which provide you with all the required calculated data, results and associated values usually associated with the Shear Stage of an Unsaturated Triaxial Test. The View, Graph and Table from the Failure stage are also available.

Clisp Studio has the ability to export the entire Test to MS Excel for further data manipulation. The Test can also be exported to a script file which can be imported when creating a new Test if desired. This enables Tests from the current or older versions of Clisp Studio to be cloned or even rerun if required.This facility is extremely useful for Test exchange between laboratories or investigation of an issue by VJ Tech.