Improved subgrade reaction model in designing embedded piles exposed to static lateral head loads

摘要

Based upon the results of recent model tests with vertical piles exposed to lateral head loads,rnsome new findings upon soil-pile head interaction are reported here. The bearing behavior of piles carryingrnoff lateral loads at the pile head towards the surrounding soil is determined by the development of horizontalrnreaction stresses, as in prototype scale for instance at bridge abutments, in offshore piling (cyclic loading withrnlow frequency due to wave excitation) or cantilevers of noise load reduction walls as to highspeed railway tracksrn(dynamic loading due to higher frequencies of wind shockwaves). In daily design practice the pile-soil-interactionrnis commonly disregarded or represented in extremely simplified forms, like linear subgrade reaction modelsrnwith stepwise control of the equilibrium between reaction stresses and passive earth pressure to be mobilized.rnThis usually leads to an uneconomic - but safe sided - design, because a strong restraining effect at the toe of thernpile is disregarded.rnThe main focus in this contribution is a simple approach to assess the development and redistribution of reactionrnstresses along the pile-axis due to the imposed head displacement of the pile in static monotonic loading.