沿海厚吹填土地层桩基缩径的控制研究

Study on Control of Pile Foundation Diameter Reducing in Thick Dredger Fill Formation in Coastal Region

摘要:

根据现场桩基成孔缩径情况和成孔检测资料，并依据工程勘察报告技术参数，分析了沿海厚吹填土地层钻孔灌注桩缩径原因，以及缩径时间与缩径量之间的对应关系，提出了解决厚层吹填土缩径的方法,一是通过添加膨润土或添加剂，增加泥浆的密度等技术指标，以改善泥浆的固壁性能；另外扩径是另一行之有效的手段，准确控制扩径量尤为重要。通过现场成孔试验及施工资料，比对分析缩径量与时间的对应关系，找出缩径规律，相对准确地得出需要扩径量，为实际工程施工提供参考依据。

关键词:厚吹填土;桩基;缩径;钻孔灌注桩;孔壁稳定性

Abstract:

According to the situation of pile hole diameter reducing and borehole detection data, and based on the engineering investigation report parameters, the causes of hole diameter reducing in thick dredger fill formation in coastal region and the corresponding relation between time and volume are analyzed. The solving methods were put forward, one is by adding bentonite or additive to increase mud weight and adjust other technical indexes in order to improve the performance of wall consolidation; another is by diameter expanding. And accurate control of the expanding amount is particularly important. With the hole formation test and construction data, the corresponding relation between diameter reducing amount and time is analyzed to find out the diameter reducing rules in order to obtain correct diameter expanding amount to provide the reference for the construction.

Key words:thick dredger fill; pile foundation; diameter reducing; bored grouting pile; borehole stability