Complex site designs create a real challenge to traditional 2D cross-sectional modeling. Currently, the majority of projects are approached from a strictly 2D point of view. In other words, site data is collected in 3D and a 2D cross-section is interpolated, with much effort, from sifting through the data, and an analysis finally performed for that particular cross-section. A limited number of cross-sections, and possibly only one, are evaluated due to the complexity of interpolating 2D cross-sections.
This approach can yield difficulties when analyzing, for example, the slope stability of sites where the geometry of the site is fundamentally irregular in all three dimensions. This can lead to the following questions:
- What if a slightly different cross-section was selected? Would the answer be significantly different?
- What is the influence of 3D geometry on the resulting 2D strata?
- What is the most likely failure direction?
A better approach is to compile and build the site data fully in 3D and then slice the model at any direction to generate appropriate 2D cross-sections. This allows the benefit of first ensuring the 3D data is correct, and proper intersections between intersected strata surfaces are resolved. The 3D model can also be evaluated in full 3D. A slice of the 3D model can be used to generate a 2D numerical model in order to provide continuity to a 2D analysis.
To use this new feature, open any 3D model and select the File > Save As... option. Change the 'System' option to '2D from Vertical Slice'. Finally, switch to the 'Spatial' tab and select the desired slicing plane.
Several slicing options are available:
- Slice on a given X coordinate, by entering a value or using the slider;
- Slice on a given Y coordinate, by entering a value or using the slider;
- Slice on an arbitrary vertical plane defined by Y = aX + b.
All model geometry, material parameters, boundary conditions, water tables, plots and other 3D objects will be converted to their 2D equivalents. A dialog will display a list of items that were not converted, or were changed to their default settings.
This process may be repeated any number of times by re-opening the original model and using different settings.
This new feature is implemented in the latest version of SVOffice™ 2009 as a free upgrade for a license holder of any of our 3D products.