Probably, the mobilization of the friction and cohesion don’t occur at the same time ora strain, moreover, the type ofvthe materials involved in a landlside should be idntified to know what parameters play important role

The most important condition that contributes to the formation of landslides is the terrain. Landslides are most common in mountainous areas, in areas with sharply crossed terrain, on high and steep slopes of river valleys, etc. The terrain and its orographic position create reserves of potential energy that cause the development of landslide phenomena.

In most cases, landslides are confined to the places where clay deposits exit (layers, interlayers, primers). Landslides are common in weakened zones: layers of coal, soot, fractures, tectonic disturbances, etc. Landslides are also observed in places where there are places of accumulation of eluvial, deluvial, proluvial, clay formations. Landslides are most likely to occur in areas where the geological structure of slopes or slopes has potential sliding surfaces oriented along the slope.

Landslides develop intensively in areas with high tectonic activity.

When analyzing the geological conditions, it is also important to take into account the structural and tectonic position of the area, since in regions experiencing the latest and modern tectonic uplifts, potential energy reserves are constantly renewed, contributing to the formation of landslides.

Slopes that are watered by rocks with water-saturated complexes, horizons and zones; with zones of permanent or temporary moisture, wetting and saturation, are more favorable for the formation of landslides compared to slopes composed of rocks that are well drained.

Favorable conditions for the formation of landslides are created with the development of accompanying geomorphological processes and phenomena. Processes of weathering, phenomena of washing and destruction of slopes, degradation of permafrost, suffusion and other filtration deformations, modern tectonic movements and earthquakes prepare conditions that facilitate the action of shear and chipping forces.

A huge influence on the development of landslide processes and phenomena are the features of the physical and mechanical properties of rocks composing the slopes. The main value is the strength of rocks - resistance to shear and chipping, as well as properties that characterize their tendency to reduce strength under the influence of various factors. In this case, it is necessary to take into account the mineral composition and structure (texture and structure) of rocks, their physical condition (humidity, density, weathering, fracturing), dampness, softening, tendency to swell, to plastic deformations, etc.

Human engineering and economic activities often create conditions favorable for the development of landslides. Pruning of slopes, steep laying of slopes, violation of surface and underground runoff, destruction of beaches, and many other human actions are comparable in distribution, scale and significance to the natural conditions of landslide formation.

Economic and engineering activities should be based on knowledge of the laws and regularities of landslide processes. They should serve as the basis for the implementation of works on the protection and transformation of territories. When studying landslide processes and assessing their threat, a comprehensive approach is needed, a comprehensive analysis that takes into account both regional and local conditions.

Hi Luis,

I published the paper below in the context of cam-clay and oedometric compression. Some might say is a bit simplistic, which I agree with but the results are positive. There is no reason you could not apply the same framework to a slope problem to complement a hazard assessment. The key is always the data, as long as you have enough samples even the simpler methods provide good insights.

https://www.researchgate.net/publication/320072606_An_assessment_of_statistically_based_relationships_between_critical_state_parameters

Look it up

DOI: 10.1080/17499518.2016.1235712

Article Probabilistic analysis of simple slopes with cohesive soil s...

Luis,

Landslides cover a wide spectrum from rockfall to quick clay failure, from those involving much water to those involving none. In all cases landslides can be examine in basically two ways - the underlying factors and the triggers. Evaluation of strength relates mainly to the nature of the underlying factors - rock hardness, rock type, degree of rock weathering, angle of slope, jointing patterns, bedding planes, porosity and/or permeability of rock/soil, clay content. In any landslide one or more of these imparts the critical weakness which the trigger exploits.

the trigger can be an earthquake, intense precipitation, overloading (as in mine waste), undercutting (as by river erosion or slope base excavation) or similar. Any evaluation of models must therefore identify 1. the main underlying factor(s) involved in any particular landslide and 2. the type of trigger involved that exploited that lack of strength at the critical time of failure.

Hope this helps,

George Strachan