Natural influences

The research carried out and the experience gained in different terrains in various parts of the world with different climates have made it possible to identify the principal and most frequent causes of rockfalls and avalanches.
External and internal factors contribute to the instability of rocks on slopes.
External factors such as climatic conditions, slope erosion, slides resulting from heavy precipitation, the freezing/thawing effect, the presence of ground water or springs, seismic activity, the action of plant roots, etc., and internal factors, such as structural movements and residual fracturing of rocks of geological nature play a role in shaping the landscape and determining the structural and morphological features of the terrain.
The resulting damage can be serious, and the effects most commonly involve highways and railways adjacent to slopes, buildings, production facilities, etc..

Sometimes, the environmental balance can be seriously affected
The landscape often includes areas that have been seriously affected by geological events (see the seismic zones), whose precarious balance continuously requires the hands of man skilfully applied to achieve a balance that satisfies all aspects of safety and at the same time safeguards the environment without altering the surface features.

In other cases, the works and infrastructures built by the hand of man have altered the environment and created problems of erosion and instability through careless planning, the destruction of vegetation, forest fires, the construction of highways along mountain slopes, excavations to meet building demands without worrying about planting trees and re-establishing the original plant cover. The places affected require the application of improvement measures designed to establish the ideal conditions of safety, while at the same time respecting the surrounding environment.

Various problems are encountered in the specific context of slope maintenance and protection of slide-prone areas.

The main problems are:

• SLIDES
• ROCKFALLS
• EROSION
• LOOSE SLOPES
• AVALANCHES

The choice of the solutions applied must guarantee maximum safety with minimum environmental impact, in other words involving as few changes as possible on the terrain.