Pile resistance to the repeatetive and alternative lateral loads

Pile foundations of the majority of buildings and structures are subjected to considerable horizontal loads varying with time as to value and direction. As to their character these loads are repeated and alternate ones and arise at seasonal and daily temperature variation, by change of wind direction, by braking on bridges by waves effect on offshore structures under effect of overhead cranes and by braking of electric-crane bridge in the industrial buildings and open crane trestles and in other cases. Repeated and alternate loads effect on resistance of piles and pile foundations has been studied recently. The results of some investigations (V.V. Mironov 1964 , M.Davisson and G.Sally 1970, M.Alizdeh and M.Davisson 1970, C.S.Oteo 1973, T.Tassios and E.Levendis 1974, L.Reese and R.Weltch 1976) concerning this problem testify to the fact that application of the above loads leads to increasing of deformation capacity and reducing of piles bearing capacity due to cyclic loads transmission onto soils. However, this is not considered in the analysis technique of horizontally loaded piles. Besides, considerable differences of cycle duration and velocity of application of these loads from static and dynamic ones do not permit to apply results for the latter. In view of the above-stated the authors have performed experimental and theoretical research on concideration of effect of repeated and alternate loads on deformation capacity of soils and piles.