墩基础的设计与应用

Design and Application of Pier Foundations

大直径扩底墩基础是近几年开始在高层建筑中运用的新桩型 ,其工作特性介于桩基与天然基础之间。它利用大直径的混凝土墩身把上部结构的荷载通过大头的端部承压传到地基的坚实土层 ,一般以端承为主 ,摩擦为辅。如果设计得当 ,可以充分利用基岩的承载性能而提高单桩的承载力。更重要的是墩桩端持力层是压缩性极好的基岩 ,因此其单桩沉降很小。

The pier fondation with large diameter expanded bottom is a new kind of pile applied in the high buildings in recent years.Its working characters are between the pile foundation and natural foundation.It transfers the load from the upper structures through the bearing larger end of the large diameter concrete pier proper to the solid earth of the base.So normally the end bearing is the primary and friction is the secondary.If the design is proper,full application of the bearing property of the base rock can increase the bearing capacity of the individual pile.More importance is that the holding course of the pier pile end is the base rock with wonderful compression and so occurrence of settlement of individual pile is rare.