In Van der Meer (2021) the stability formula for rock slopes under wave attack has been rewritten to remove mean period Tm and include spectral Tm-1,0. This is now identical Modified in Rock Manual (2007 – Eqs 5.139 5.140), except its coefficients use of H2 percent H1/3 (2021). A method given by cpl csu formula, (new) data on slope where results differ from original data. The re-fit shallow wat...

The stability of a rock slope depends on the rock mass geo-structure and its discontinuities. Discontinuities show up at the rock surface as smooth and often plane surfaces. From their location and orientation the main families of fractures can be inferred and a stability analysis performed. To gather information on their distribution, surveys are typically carried out with geological compass a...