不同厚度褥垫层刚性桩复合地基工作特性研究

对刚性桩复合地基褥垫层的工作机理进行了分析。并据此设计了桩竖向刚度很大的刚性桩复合地基模型试验。进行了桩顶进入不同厚度褥垫层的复合地基试验，研究了刚性桩复合地基褥垫层在竖直荷载作用下的工作性状。结果表明：竖向刚度很大的桩即使在100mm厚褥垫层情况下也很难充分发挥其承载力，桩顶下设置一定厚度的褥垫层有助于提高桩的荷载分担比，减小刺入量。

Study on behavior of rigid pile composite ground with different cushion thicknesses

The working mechanism of cushion in rigid pile composite ground is analyzed conceptually. Based on that, loading tests were performed on rigid-pile composite ground where pile has very large vertical stiffness to investigate the behavior of cushion of rigid-pile composite ground under vertical load. Gravel cushion with different thicknesses is laid beneath loading plate, while pile head is thus separated from loading plate by the gravel cushion. Pile head was embedded in the cushion for a certain length in one of the tests. Test results show that the bearing capacity of pile even with 100mm thick cushion can hardly be mobilized. The embedment of pile head into cushion can increase the load carded by the pile head; in the meantime reduce the penetration of pile head up into the cushion.