8. INTERVENTION OF A SLOPE STABILIZATION

In a stabilization project, the geotechnical interventions adopted to increase the safety far beyond the limits provided by laws, are chosen according to the peculiarities of the physical -evolutional model of the real or  hypothetical instability and in relation to the elements distinguishing and causing the instability itself.
Additionally,  the presence and the importance of the urban, industrial and different infrastructures  located in the area subject to the intervention, determine the stabilization plan itself,  the choice of techniques to be used  and relevant cost and timing .
In case of unstable slopes, different  excavation works can be carried out so to lighten up the part of the area potentially moving.  Slopes re-profiling works, instead, reduce the slope inclination by carrying out either tiers and layers or a unique level of sloping parts.
Scaling works,  are either the mechanical or by explosive charge removal of dangerous and unsafe rocks.
Bridles are built up  as barriers to water courses . They are built up of either dry or cement bricks, of wood, ground, in gabions or prefabricated elements and their consolidation effect is achieved when reducing the water speed and erosion force.  
Depending on their use and form, bridles  can form different waterbed drops or block the material dragged by flood or  they can also filter  and select water when temporarily blocking the material dragged by water and slowly release it thanks to “gates” (openings), different in forms and dimensions
Of limited height, bridles jut out from the river-bed.
Differently, when deep river-bed consolidation works are required, sills are built in the bottom of the stream to decrease water .
The stabilization of slopes also include  base (foot)support works.
They lean on stable parts of slopes and thanks to an excellent draining system, they increase the resistance forces, ultimately the slope stability.
Foot support works can be either “rigid” (opposite bank, under scarp or support works) or flexible (sheet pilings, bulkheads, walls in gabions, curtains of piles in jet grouting stabilized ground, curtains of micro-piles in reinforced concrete).
Other interventions are those related to the hydraulic-forestry  field works.
They reduce the surface erosion of slopes caused by uncontrolled waters and, therefore, prevent any superficial movement of the slope.
They are built up either by  wood piling (dry walls and in gabions, trellis) or by fascines (mattresses and fences).
Drain-end works are performed when watercourses cross inhabited areas. They reduce the erosion of slopes and the  river-bed subsidence by covering it with stones (dry, mortar and cement bound).
Finally, foot slope stabilization works include longitudinal interventions (cliffs) made by natural or artificial stone randomly placed in the area eroded by water.