EFFECTS OF INSTALLATION ON THE MONOTONIC STATIC UPLIFT CAPACITY OF HELICAL ANCHORS
Abstract
Helical anchors bear on the soil mass they are installed through. Subsequently, poor installation quality may negatively affect the uplift capacity of these anchors. To observe the effects of anchor installation on the load-displacement behavior and static uplift capacity of helical anchors, thirteen single-plate helical anchors were installed in clean to silty-sand soils with a variety of advancement ratios and tested in tension. Preliminary results suggest reduced site-specific torque correlation factors could be employed to account for installation effects when predicting static uplift capacities. Reduced site-specific torque correlation factors could be applicable if advancement ratios are above a certain minimum threshold requiring further definition but beneath the recommended 0.8. Additionally, pre-loading anchors with advancement ratios between 0.5 to 1 may consolidate soil loosened during installation, allowing the anchor load-displacement behavior to resemble traditional end-bearing behavior more closely.