One-dimensional Consolidation

Example posted by: Christopher McGann, University of Washington

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This article describes the OpenSees implementation of a 1D consolidation model. A single soil column is modeled in two-dimensions, but all compression is one-dimensional. The model can consider either single or double drainage of the soil layer.

The input file needed to execute this analysis, 1Dconsolidation.tcl, is provided along with several helpful Matlab scripts to plot the results, plotPorePressure.m and plotStress.m.

Download them all in a compressed file: consolidation.zip

To run this example, the user must download the file 1Dconsolidation.tcl. Once this has been done, the user can then type "source freeFieldDamp.tcl" into the interpreter of the OpenSees.exe application to run the analysis. The Matlab scripts are not essential to the analysis, however, they are provided to demonstrate how certain plots can be obtained from the recorded output.

Model Description

Fig 1. Schematic representation of the consolidation model. Blue nodes are corner nodes. Red nodes are interior nodes.

Soil Elements

Fig 2. Connectivity for 9_4_QuadUP element.

Representative Results

Fig 3. Distribution of excess pore pressure in soil layer for single drainage. Initial time step is blue, then advancing steps become green, then red. Final step is black.

Fig 4. Distribution of excess pore pressure in soil layer for double drainage. Initial time step is blue, then advancing steps become green, then red. Final step is black.

Fig 5. Distribution of vertical stress in soil layer for double drainage. Initial time step is blue, then advancing steps become green, then red. Final step is black.

Fig 6. Comparison of settlements at the surface of the soil layer for single and double drainage cases.