预应力管桩及灌注桩抗拔变形的研究

Research of tension piles displacement differences between PC pile and bored pile

近年来,随着建筑物地下室层数的不断增加,抗拔桩广泛用于实际工程中。但在使用的过程中,特别是在沿海地区,发生过多起地下室底板隆起的事故。显而易见,这些事故都是由于抗拔桩失效所导致的。在此前十年里有大量的文章讨论了抗拔桩的承载能力,也有少量的文章对抗拔桩的变形机理进行理论分析。但能够区分预应力管桩及钻孔灌注桩的工作状态,并对比他们的抗拔刚度的研究甚少。然而正因为这两种桩刚度的巨大差异,会导致地下室底板由于支座位移不同,而产生底板受力性能的改变。所以对不同桩抗拔刚度的研究密切关系着地下室底板的安全。

In recent years,with the increase of the number of building basement,tension pile is widely used in practical projects. But in the use of tension piles,especially in the coastal areas,there are too many accidents in the basement bottom slab heave. It is obvious that these accidents are caused by the failure of tension piles. Over the past decade,a large number of articles discussed the bearing capacity of tension piles,and also a small amount of the article on the deformation mechanism theoretical analysis of tension piles. But it is very few article can distinguish the working status of prestressed pile and bored pile,and the study the stiffness differences between these two piles. However,the huge stiffness difference between these two kinds of pile will lead to the basement bottom slab performance change due to the displacement difference. Therefore,the research on the uplift displacement of the two different piles is closely related to the safety of the basement floor.