PHC桩穿越深厚密实砂层可打性分析及现场试验研究

FEASIBILITY ANALYSIS AND FIELD TEST ON DRIVING PHC PILE THROUGH DEEP DENSE SAND

由于PHC桩经在穿越深厚砂层过程中常造成桩头、桩身疲劳破坏,从而无法沉桩至设计标高。为综合分析此类工况下PHC桩的可打性,本文通过GRLWEAP软件对穿越深厚密实砂层工况的PHC桩进行打桩波动方程模拟,同时在工程现场开展高应变打桩监测试验。研究发现PHC桩穿越深厚密实砂层除了需要选择合理的打桩系统和打桩工艺外,还须采用引孔措施以及对桩身和桩靴进行必要的加强处理。为穿越深厚密实砂层工况下选用PHC桩的设计和施工提供了科学依据。

Driving PHC pile through deep dense sand conditions often causes damage to the pile. The pile can't be drived into the design depth. Driving PHC pile through deep dense sand layer is analyzed using GRLWEAP for comprehensive analysis of these conditions of PHC pile to drive. The high strain monitoring test is also carried out.The research finds that it is feasible to drive the PHC pile through deep dense sand layer with reasonable selection of pile driving system and driving technology. Besides,it is necessary to take guide-hole measures and strengthen the pile body and pile shoe of PHC pile. The findings can provide a scientific basis for the design and construction of PHC pile in deep dense sand conditions.