A tool for soil nail wall design optimisation using Slide2 and Python

Optimised soil nail wall designs can result in reduced material costs, reduced construction program and reduced construction risk. Optimisation through assessing a large number of models manually has, in the past, been practically unfeasible due to the user time involved in model development and interrogation. The use of interfacing tools with the python scripting language, either through an included Python API or through modifying text-based models directly, has the potential to significantly reduce the time required for rigorous optimisation. This time reduction through digital tools, will lead to realisation of all the benefits design optimisation allows.

To demonstrate the above, this paper presents a python tool for assisting in the optimisation of soil nail wall design. It is implemented through the 2D limit equilibrium method software, Slide2, although may be applied to other software. Using the tool, an engineer can determine optimal soil nail lengths for a given slope angle, soil nail inclination, nail spacing, nail location (offset), and number of nails. Combinations of these parameters may also be assessed automatically to find a globally optimal solution. An example is given where a design was optimised simultaneously across multiple scenarios with different safety factors (e.g. flooding, earthquake, etc.). The use of this tool allows the engineer to identify the influence of key variables and quickly calibrate the optimised design to the specific constraints of the project.