分层地基环境下海上风电大直径单桩基础水平承载特性分析

Analysis on Horizontal Bearing Capacity of Large-diameter Monopile Foundation for Offshore Wind Power under Stratified Foundation Environment

依托某海上风电项目,针对几种典型地层条件通过数值方法研究分层地基环境下单桩水平承载性能影响因素并进行参数敏感性分析。首先,在用钢量恒定情况下,桩径对单桩水平承载力影响最大,且这种影响随着桩径增大而显著增大;其次,随着埋深的增大,水平承载力先增大而后趋于稳定;再次,桩周浅层土体弹模对桩基承载力亦影响较大,且桩径越大,其影响越明显且不能通过增加埋深来抵消。与均质地层相比,水平承载力在上劣下优地层中下降最为明显,在上优下劣及中夹差土地层中降幅较小。实际工程中除增大桩径或桩长,亦可对单桩周边浅层土体进行加固以提高水平承载性能。

Based on an offshore wind power project, the influence factors of horizontal bearing capacity of monopole in stratified foundation environment are studied by numerical method and the parameter sensitivity analysis is conducted according to several typical stratum conditions. When the amount of steel used is constant, the pile diameter has the greatest influence on the horizontal bearing capacity of monopile, and the influence increases significantly with the increase of pile diameter. Secondly, with the increase of buried depth, the horizontal bearing capacity increases first and then tends to be stable. Thirdly, the shallow soil elastic model around the pile also has a great influence on the bearing capacity of the pile foundation, and the larger the pile diameter is, the more obvious the influence is, which cannot be offset by increasing the buried depth. Compared with the homogeneous layer, the horizontal bearing capacity decreases most obviously in the upper inferior and lower superior layer, and the decrease is smaller in the upper superior and lower inferior layer and the middle sandwiched layer. In practice, in addition to increasing the pile diameter or pile length, the shallow soil around the momopile can be strengthened to improve the horizontal bearing capacity.