A simplified numerical approach for studying the pile-landslide interaction in hard soils

Vertical piles can be profitably employed as deep retaining structures to prevent landslides, providing a convenient restraint to soil movements. The design procedures commonly employed in engineering practice to evaluate the mechanical response of piles to lateral loads are usually based on P-y curves, giving the value of the local interaction force as a function of the local pile deflection (i.e. the interaction between each slice of the pile and the surrounding soil). In the present paper a simplified procedure, capable of computing the global resultant interaction force arising between the pile and the soil moving mass as a function of the soil displacement, is presented. Non linearities of both the structure and the soil can be taken into consideration, in particular with reference to the case of piles drilled in hard soils, usually characterized, these latter, by a softening mechanical behaviour. The influence of both the shape of the soil displacement profile and of additional constraints (like deep pretensioned ground anchors) is investigated as well.