超静孔隙水压力影响的海上风机桩基承载力高应变检测方法研究

海上风机大多采用桩基,单桩承载力是评价桩基设计和施工质量的重要参数。高应变法是目前常用的单桩承载力检测方法,为获取桩基承载力最终值,通常需在沉桩后达到休止时间方可进行复打测试。受施工条件和成本的限制,海上风机桩基进行复打测试难度较大,一般条件下无法完成。本文通过计算沉桩时的超静孔隙水压力,结合沉桩时桩基承载力的高应变检测值,分析超静孔隙水压力完全消散后的桩基承载力,并通过现场试验验证了该法的合理性,且在实际工程中得到了应用,可为类似工程的桩基设计及检测提供参考。

Study on the high strain technology for the bearing capacity of the offshore wind turbine pile foundations considering the effect of excess pore water pressure

The driven-pile is the most common foundation for the offshore wind turbine.The load bearing capacity of a single pile is a very important parameter for evaluating the design and installation of the pile foundation.The high strain technology is a widely used method to measure the load bearing capacity of the pile.In order to get the limit bearing capacity of the pile,it is usual to drive the pile with the hammer after the pile has been installed.But this technology can not implemented for offshore wind turbine foundations because of the restriction of the marine construction environment and project cost.The excess pore water pressure caused by the driving pile is calculated with finite element method.By use of the high strain technology,the initial load bearing capacity of a pile can be obtained.The load bearing capacity of a single pile is estimated with the excess pore water pressure and the initial bearing capacity of the pile,this numerical method is valid because the calculation results agree with the field data,and this method has been used in the marine project.This method has provided reasonable evidences for the foundation design and mearsure of the similar projects.