CPT-based design method for helical piles in sand
CPT-based design method for helical piles in sand
复制标题
基于CPT的砂土螺旋桩设计方法
DOI：
10.1139/cgj-2022-0209
复制
发表时间：
2023
影响因子：
3.6
通讯作者：
Bittar E
中科院分区：
文献类型：
--
作者：
Bittar E
螺旋桩广泛用于低层和中层建筑，在需要抵抗显著上拔荷载的情况下，螺旋桩是一种流行的地基解决方案。螺旋桩的再利用能力以及最近人们对将其用作海上风能和太阳能应用的基础的兴趣，重新引起了人们对改进现有设计方法的兴趣。本文介绍了在中密和密砂中进行的现场调查结果，这些调查研究了不同螺距、轴直径、前进比和轴尖几何形状对轴向拉伸和压缩能力的影响。进行的20个桩试验（其中许多试验包括仪器）的结果表明，对一系列调查参数的敏感性较低，且能力与静力锥贯入试验阻力的相关性较强。基于这些研究结果的设计方法，提出了典型的螺旋桩几何形状，并显示提供的预测，一般在10%至15%的轴向能力报告的30个其他有据可查的桩测试报告在文献中。该方法被称为UWASP-22，包含一种估计螺旋桩载荷-位移响应的简单方法以及一种能够预测安装扭矩的公式，这是螺旋桩的常见质量控制措施。
Helical piles are used extensively for low and medium rise developments and are a popular foundation solution in cases where resistance to significant uplift loads is required. The ability to re-use helical piles and recent interest in their use as foundations in offshore wind and solar energy applications has renewed interest in improving existing design methods. This paper presents the results from field investigations in medium dense and dense sand that examine effects on the axial tension and compression capacity of varying the helix pitch, shaft diameter, advancement ratio and shaft tip geometry. The results from the 20 pile tests conducted (many of which included instrumentation) indicate low sensitivity to a range of the investigated parameters and a strong correlation of the capacity to the cone penetration test resistance. A design method based on these findings is proposed for typical helical pile geometries and is shown to provide predictions that are generally within 10 to 15% of the axial capacities reported for 30 other well documented pile tests reported in the literature. The method, referred to as UWASP-22, incorporates a simple means of estimating the load-displacement response of a helical pile as well as a formulation enabling prediction of the installation torque which is a common quality control measure for helical piles.