It is critical to pay attention to the pore water pressures as they tend to increase over time. This means that cheap, undrained shear strength tests are only useful if looking at very short term stability.

The geological sequence and history must be known so we are sure if there are existing tectonic shears.

Excavations are more susceptible to the effects of tectonic shears than embankments because embankments raise the normal effective stresses on potential sliding surfaces, and these offset the increased levels of shear stress they impose.

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