不同成桩工艺对支盘桩承载性能影响的模型试验研究

介绍了新型变直径灌注桩——挤扩支盘桩和旋扩珠盘桩的工作原理、主要优缺点.设计了模拟挤扩和旋扩成盘的模型试验方案并进行了一系列的模型试验,根据试验结果分析了新型变直径灌注桩在承载和抵抗变形方面与普通等直径桩相比的优越性,同时还比较了挤扩和旋扩这两种不同施工方法对变直径桩承载力和变形的影响,讨论了它们在荷载传递上的区别.研究表明,挤扩成盘时由于施工期间挤密盘周土体使盘的承载力高于旋扩成盘的承载力,从而使挤扩支盘桩盘的承载作用大于旋扩珠盘桩的承载力,同时前者盘的作用也要明显大于后者,因此在设计和施工时应充分注意各自的特点.

Model Test Research on Bearing Capacity of Variational Diameter Cast-in-place Piles by Different Construction Ways

The paper introduces the working principle and the merits and drawbacks of new-type variational diameter cast-in-place piles-the piles with plates by compaction and the piles with plates by rotation.A model test plan of simulating compaction and rotation was designed and a series of model tests were taken.According to the model test results,we analyzed the advantages of the new-type variational diameter cast-in-place piles in terms of loading ability and deformation.At the same time,we compared the impacts the two different construction ways had on the loading ability and deformation of the variational diameter piles,and discussed their differences in load transfer.The research results indicate that because the soil compaction effect on the plates' bearing capacity is bigger than that of the plates by rotation,the bearing capacity of the piles with plates by compaction is bigger than that of the piles with plates by rotation.Therefore,during design and construction,we should pay more attention to their own characteristics.