竖向荷载作用下支盘桩水平动承载性能模型试验研究

MODEL TEST STUDY OF BEARING PERFORMANCE OF SQUEEZED BRANCH AND PLATE PILE UNDER THE ACTION OF LATERAL VIBRATION LOAD AND VERTICAL LOAD

在对模型桩基施加水平振动荷载的同时,施加桩顶竖向荷载,对一根等直径桩和两根承力盘位置不同的支盘桩进行模型对比试验。结果表明:支盘桩与等直径桩相比,其承担水平动荷载的性能更加优越,且支盘桩的承力盘的位置接近桩顶时,这种优越性表现更明显;桩身动弯矩的大小随着水平振动荷载幅值的提高而增大;在水平动荷载数值较小时,竖向荷载的存在能够适当降低桩身弯矩值,对桩的水平动承载性能有利;当桩身水平动荷载数值增大,竖向荷载将会增大桩身弯矩而变为不利因素。

Applying both lateral vibration load and vertical load at the top of the model piles,a model test was done for a common straight pile and two squeezed branch and plate piles. The results of model test showed that the bearing behavior of the squeezed branch and plate pile was superior to the straight pile under complex loads. For the squeezed pile,when the plate was nearer to the pile top,the superiority was obvious. The moment value in the pile shaft increased with the lateral vibration load increasing. When the lateral vibration load was lower,the vertical load could reduce the pile shaft moment amplitude,and it was favorable to the pile. But when the lateral vibration load increased to a higher level,the vertical load would increase the pile shaft moment amplitude,and it was unfavorable to the pile.