Benchmark solution
----------------------


Calculation method
~~~~~~~~~~~~~~~~~~~~~~~~


The reference solution comes from example 3 of the Griffiths article
and Lane [:ref:`1 <ref-1-v603007>`].

In this article, the result from method SRM was compared with that given by
Tayler et al., which uses the type LEM method adapted to
non-circular surface [:ref:`2 <ref-2-v603007>`].



Benchmark result
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~


In the article by Griffiths and Lane, the authors vary the ratio
between the cohesion of the weak layer and that of the slope to test the
consistency between result SRM and result LEM, as shown in :numref:`fig2-FS-trace`.

When :math:`\lambda ={c}_{2}/{c}_{1}=\mathrm{0,2}`, we saw that the
method LEM assuming circular fracture surfaces led to a
FS bigger and unrealistic, while methods SRM and LEM assuming
the non-circular surfaces were in good coherence and give the value
Just FS. This highlights the need to use the Morgenstern-Price method
to locate the typically non-circular fracture surface and calculate the
correct FS value.


.. figure:: images/100000000000029800000261ADC973A0A18C6309.png
 :name: FIG2-FS-Trace
    :width: 40%

    **Plaxis2D result - FS plot as a function of absolute displacement at the peak of the slope**

.. _refImage_100000000000029800000261 ADC973A0A18C6309 .png: