Centrifuge modeling of axial behaviour of helical piles

螺旋桩基础广泛应用于加拿大的建筑业。螺旋桩由一个钢管轴和一个或多个连接到轴端的螺旋组成。螺旋桩与传统的直桩相比，具有承载力大、可重复使用、安装快速等优点，这些优点使螺旋桩特别适合加拿大的建筑业。近年来，加拿大的桩制造商开发了创新的螺旋桩类型，以满足行业不断增长的需求。这些桩通常具有较大的直径，并承受较大的静态或循环荷载。桩的设计方法尚未得到很好的确立或通过载荷试验验证。事实上，由于大直径桩的承载力很大，而且原位测试的成本过高，因此几乎不可能对大直径桩进行原位载荷测试。因此，有必要对螺旋桩的现场工作性能进行全面的研究。** 通过与Almita Piling Inc.合作，加拿大螺旋桩的制造商，阿尔伯塔大学的研究小组将利用土工离心模型试验研究土壤-螺旋桩的相互作用。土工离心模型是一种具有挑战性的土工和结构问题的实验室测试方法。拟议的研究将开发在阿尔伯塔大学的离心机上安装模型螺旋桩的技术和基础设施;该研究将对安装在粘性和无粘性土壤中的模型螺旋桩进行载荷试验。该研究还将进行数值模拟，以校准测试结果。拟议研究的结果将通过提供具有成本效益和可靠的实验室测试方法使工业合作伙伴受益。研究结果有助于加深对螺旋桩工作性能和桩土相互作用的认识.这项研究将有利于加拿大的建筑业提供一个有能力和经济的基础类型。

Helical pile foundations are widely used in the construction industry across Canada. A helical pile consists of a steel tubular shaft and one or more helices attached to the end of the shaft. Helical piles have many advantages such as large capacities, reusability, and rapid installation, compared to conventional straight-shaft piles; these advantages make helical piles especially suitable for the construction industry of Canada. In recent years, innovative helical pile types have been developed by pile manufacturers of Canada to meet the increasing demand of the industry. These piles often have large diameters and are subject to large static or cyclic loads. The design methodology of the piles has not been well established or validated by loading tests. In fact, it is nearly impossible to conduct in-situ loading tests for large-diameter piles due to the large pile capacities and the prohibitive cost of in-situ tests. Hence, a research program is necessitated for a comprehensive study of the in-situ performance of helical piles. **By partnering with Almita Piling Inc., Canada's manufacturer of helical piles, the research team at the University of Alberta will investigate the soil - helical pile interaction using geotechnical centrifuge model tests. Geotechnical centrifuge modeling is a laboratory test method for challenging geotechnical and structural problems. The proposed research will develop the technique and infrastructure for installing model helical piles on the centrifuge at the University of Alberta; the research will conduct loading tests of model helical piles installed in cohesive and cohesionless soils. The research will also conduct numerical modeling to calibrate the testing results. The outcome of the proposed research will benefit the industrial partner by providing a cost-effective and reliable laboratory testing method. The outcome will advance our understanding of the performance of helical piles and the soil - pile interaction. The research will benefit Canada's construction industry by providing a capable and economic foundation type.