aliasgere
Civil/Environmental
- Jan 14, 2012
- 25
In my offshore drained clay analysis, I have been trying to vary k0 with depth in the clay to model overconsolidation. I am using the porous elasticity and modified cam clay constitutive models. However, when I run the geostatic step, even before the input file is processed, the following error is generated 'the sum of the initial pressure and elastic tensile strength for a porous elastic material in element xx in instance soil must be positive'. This error is generated for more than half of the elements. My initial model was 3D but I constructed a 2D column of soil to test this but the same error was obtained.
The pore pressure was prescribed to be 40kPa at the surface of the soil and 600kPa at the base of the soil (depth of 56m). A uniform pressure of 40 kPa simulating pressure due to water head of 4m was applied to the soil surface to generate the required pore pressure distribution.
When I increased the effective stress by 40kPa at all the soil layers, the analysis runs. However, this is incorrect as effective stress should be zero as the pressure of 40kPa is taken by the pore fluid.
Anyone with any ideas on what the cause of this error could be?
Many thanks.
The pore pressure was prescribed to be 40kPa at the surface of the soil and 600kPa at the base of the soil (depth of 56m). A uniform pressure of 40 kPa simulating pressure due to water head of 4m was applied to the soil surface to generate the required pore pressure distribution.
When I increased the effective stress by 40kPa at all the soil layers, the analysis runs. However, this is incorrect as effective stress should be zero as the pressure of 40kPa is taken by the pore fluid.
Anyone with any ideas on what the cause of this error could be?
Many thanks.