and for tye y-axis: Stress (point: A type q). 1 Simple modeling of standard laboratory tests with PLAXIS Version 8 To model standard laboratory tests with PLAXIS 8 a simple (axisymmetric) model of 1x1 m 2 without gravity. This option is available in the material data base of the Plaxis 8.4 Input program (V.I.P version). Soil tests: Plaxis version 8.4 has a convenient option to run simple soil tests (triaxial, oedometer) on the basis of defined material data sets using a single stress point algorithm. In the Curves program, select for the x-axis: Strain (point: A type: ε 1 ) and for tye y-axis: Stress (point: A type q). After viewing the results of the final step, press the Curves icon (upper left corner). After the calculation, press to view the results of the final calculation step. Subsequently press Back in the Calculations program, press to start the calculations. At these points the stresses and strains will be stored for stress-strain curves. Select (an) arbitrary stress point(s) in the middle of the mesh. The horizontal load remains equal to the confining pressure > Press the button 'Select points for curves' and subsequently press the button 'Select stress points for stress/strain curves'. Loading input: Staged Construction > In the Staged Construction window, increase the axial load by -100 kN/m 2 to -200 kN/m 2 (ph.2), -300 kN/m 2 (ph.3), -400 kN/m 2 (ph.4) respectively. Loading input: Staged Construction > In the Staged Construction window, activate the distributed load and see if the load at both lines is still -100 kN/m 2 > Phase 2 - 4: Axiale loading General: Calculation type: Plastic Parameters: To let the displacements and strains start from zero, select only in Phase 2 the option 'Reset displacements to zero'. If the material data set is 'Undrained', this can be achieved by selecting the option 'Ignore undrained behaviour' te selecteren. In the Calculations program, four calculation phases should be defined: Phase 1: Isotropic compression General: Calculation type: Plastic Parameters: In a CU-test, this phase can be considerd drained. After a few seconds the Calculations program is started. Save the input under an appropriate name (for example 'Triax'). Subsequently, press (initial pore pressures and effective stresses should remain zero in this simple modeling).
#Triaxial test plaxis 2d pdf update#
3 Define Update Update Update Calculate Output Initial conditions Calculate Define Press and accept the standard unit weight for water (10 kN/m 3 ). The geometry model should look as follows: Press the 'Generate mesh' button to generate the finite element mesh and subsequently press to return to the input program. 'Drag' the data set to the geometry model and 'drop' it on the cluster. Materials > Soil & interfaces: Create a new data set and enter the model parameters listed at the end of this section. Do this for both geometry lines with distributed loads. This can be done by double-clicking the geometry line at which the load is acting (use the selection tool) subsequently select 'Distributed load (system A)' from the selection window and enter -100 for both y-values. In this case the initial value must be set to the confining pressure (for example -100 kN/m 2 ). File > General settings: The geometry model is constructed as follows: Geometry > Geometry line: (0 0) > (1 0) > (1 1) > (0 1) > (0 0) Loads > Vertical fixities: (0 0) > (1 0) Loads > Horizontal fixities: (0 0) > (0 1) Loads > Distributed load system A: (0 1) > (1 1) > (1 0) 2 Update By default, distributed loads have a unit value which are pointing towards the model. Underneath an example is given of the modeling of a triaxial test. 1 Simple modeling of standard laboratory tests with PLAXIS Version 8 To model standard laboratory tests with PLAXIS 8 a simple (axisymmetric) model of 1x1 m 2 without gravity stresses can be used.
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