Bem2d.jl is a Julia library for two-dimensional plane strain linear elastic boundary element (BEM) calculations related to earthquakes and tectonics.
The ideas behind Bem2d.jl are described in detail in the paper: "Bem2d.jl: A quadratic co-location two-dimensional boundary element approach to quasi-static faulting problems with gravity and non-planar topography", Meade, Thompson 2021, Computers & Geoscience
- Analytic quadratic slip and traction elements (Portella et al., 1992)
- Surface topography & non-planar fault surfaces
- Unidirectional gravity (Pape and Banerjee, 1987)
- Kinematically consistent quasi-dynamic earthquake cycles with slip and aging laws
A simple starting example of a thrust fault with a topographic surface can be generated with:
using Bem2d
include(“examples/faultboxgravitytopo.jl”)should produce this figure:
These serve as reference examples (and some as effectively tests) with the intent of making clear how to build simple to complex BEM models
faultboxgravitytopo.jl - A single planar fault in a box with a non-planar topography and unidirectional gravity. Currently with constant slip elements.
bemvsdeepokada.jl - [works on Linux, because of okada_wrapper dependency] -
Comparision between fundamental fullspace 2D elastic disloation soluitons and Okada's half space 3D solutions.
braziltest.jl - Traction only compression of a homogeneous disc (Brazil test)
constvsquadelements.jl - Basic comparision of constant slip vs. 3 node quadratic elements.
discmaterial.jl - A simple two domain problem. An inner annulus surrounded by a an unbounded region with different material properties. Crouch and Starfield solve this for using fictious force vs. the DDM approach here.
gravitybox.jl - Homogenous square compressing under the force of gravity with a no slip bottom boundary condition.
kelvin.jl - Comparison of point source kelvin solution with finite source DDM approximation.
nearsurfaceerror.jl - Comparision of constant element vs. 3 node quadratic element errors when compared with Okada. [works on Linux, because of okada_wrapper dependency]
weldedcircle.jl - A basic two domain example consisting of a circle cut into upper and lower halves with differing material properties. Traction boundary conditions apply on the top of the circle and no-slip boundary conditions on the bottom half.
weldedcirclefault.jl - A basic two domain example consisting of a circle cut into upper and lower halves with differing material properties and fault in the upper domain. The upper half of the circle boundary is traction and no-slip boundary conditions on the bottom half.
Bem2d.jl has its own docker image! Before, continuing, follow these directions to make sure you have the latest version of docker and docker-compose:
- https://docs.docker.com/install/ (also, on Linux, make sure to follow the post-install instructions: https://docs.docker.com/install/linux/linux-postinstall/)
- https://docs.docker.com/compose/install/
To test that out, try running docker run hello-world.
If that works, let's launch a Jupyter notebook with Bem2d.jl installed. Run: ./launch_jupyter That should first download or build the docker image which includes installing all the dependencies for Bem2d.jl. Afterwards, it'll launch a Jupyter Lab server instance. Find the line in the output saying [I 19:20:33.891 LabApp] The Jupyter Notebook is running at:. The next line should tell you what port the server is running on. Open your browser to localhost:THATPORT and play around!