Quick Start: First Analysis

This tutorial walks through a complete analysis: draw a slope, assign a material, optionally add a water table, choose a search and analysis method, and read the critical factor of safety. It uses the default project that opens when you start JW Slope.

All work happens in the Geometry workspace tab (selected by default) until the final step, when results appear on the Results tab.

1. Draw the external boundary

The external boundary defines the full cross-section of soil to be analyzed.

1. In the geometry dock, open the External Boundary group and choose New External Boundary.
2. Click on the canvas to place each vertex of the slope profile, working around the full closed outline (ground surface, slope face, and base).
3. Close the boundary to finish the polygon.

2. Define and assign materials

A new model starts with a default material. To edit its properties or add more:

1. Open the Materials group and choose Define Materials. This opens the Define Material Properties dialog.
2. Set the strength model (for example, Mohr-Coulomb), unit weight, cohesion, and friction angle. Close the dialog when done.
3. If the model has more than one material region, use Assign Materials (or right-click a region on the canvas and choose Assign Material) to map each region to a material.

For a single-material slope, the default material assignment is sufficient.

3. (Optional) Add a water table

To include pore pressure from a phreatic surface:

1. Open the Water Table group and choose New Water Table.
2. Click along the canvas to trace the water-table line from one side of the model to the other.
3. Close the line to finish.

The pore fluid unit weight defaults to 9.81 kN/m³. See Units & Conventions for the sign and unit conventions.

4. Choose the search method

1. Open the Limit State group and open the slip-search settings.
2. Set Search Method. For a first run, Auto Refine Search (Circular) finds circular surfaces automatically.
3. Set Failure Direction (Left to Right or Right to Left) to match the downslope direction of your section.

5. Choose the analysis method

1. In the analysis-method settings (the Analysis Method checklist), tick one or more solvers. Bishop Simplified is a good starting point.
2. You may select several methods at once (for example Bishop, Spencer, and GLE) to compare results in a single run.
3. The Target Number of Slices defaults to 30.

6. Run the analysis

1. Open the Compute group and press Compute.
2. The LEM Solver dialog opens and shows live search progress while the surface search runs. The button reads Computing... during the run.
3. When the search completes, the workspace switches to the Results tab.

7. Read the result

On the Results tab, the critical slip surface is drawn on the canvas and the critical factor of safety is reported. If you selected multiple analysis methods, a factor of safety is reported for each.

Next steps

• Add loads and support to refine the model.
• Try non-circular and metaheuristic searches under slip surfaces.
• Organize variations as scenarios to compare cases side by side.