离心场中风力电机桩基复杂加载测试设备的研制

Complicated loading device for pile foundation of wind-driven generator in centrifugal field

桩基础是近海风力发电中经常采用的基础形式,承受着包括低频风循环荷载在内的复杂荷载组合。为了采用离心模型试验来研究风机桩基础特性,研制了离心场中风机桩基础复杂加载测试设备。该套设备除了可以施加水平向和竖向静力荷载外,还实现了离心场中长时间低频率的水平循环加载,并能够实现多种荷载同时或者先后施加。通过一系列测试试验,验证了该套设备的有效性,满足离心模型试验中对模拟风机桩基础的复杂荷载要求。初步试验结果表明,桩顶水平位移随着水平荷载循环周数的增加而增大,但增长速率逐渐减小,至一定周数后,桩顶位移趋于稳定,土体变形主要集中在桩周一定区域内。

Piles are widely used as a foundation for the offshore wind power generation and undergoing a complex combination of loads including the low-frequency cyclic wind loading.A new device has been developed to simulate the complicated loads on the piles during the centrifuge model tests.Apart from the horizontal and vertical static loads,this device can also realize a long-time and low-frequency cyclic load,with a combination of other types of loads that are applied simultaneously or successively.The validity of this device,that it can meet the requirement for simulating the complicated loads that the pile undergoes,is preliminarily verified via a series of tests.The test results show that the displacement of pile top increases with increasing number of cycles of horizontal cyclic loads;but the growth rate gradually decreased with the displacement tending to stabilize after a certain cycles;and the deformation of soils concentrates in a certain region near the pile.