Design Guides

Design Considerations

Theoretical Capacity Capacity – Torque Correlations Buckling Lateral Resistance Corrosion Group Efficiency Specifications Site Access Contaminated Soils Economics For additional design information click here.

Torque VS Capacity

The relationship between torque applied during anchor installation and the installed anchor’s load capacity The torque versus anchor capacity method was used to verify the load capacity at installation. This method multiplies the effective torsional resistance encountered during installation of the helical anchor by an empirical factor to determine the compression load limit or pullout […]

Predicting Capacity

Capacity is the maximum load a foundation/soil system can support Bearing capacity varies depending on the following factors Soil properties Soil conditions Anchor design characteristics Installation parameters Load Type:Tension – Compression – Shear

Calculating Capacity

Individual Bearing method This method assumes a bearing failure of the soil supporting each helix Bearing capacity varies as a function of the soils angle of internal friction and the soil density description Capacity is determined by calculating the ultimate bearing resistance of the soil at each helix and multiplying it times the projected area […]

Soil Cohesion

Commonly, soil is not homogeneous through the entire required depth of installation; a soil behavior analysis must be done in order to be able to calculate the theoretical ultimate capacity and varies quite a lot depending on the site conditions. Cohesion is the term used for shear strength that exists in the absence of compressive […]

Projected Helical Plate Areas

The projected area of an individual helix is the area of the helix plate less the cross sectional area of the shaft. The sum of the projected total area is required to determine the capacity of a helical anchor. Helical Anchors, Inc. usually recommends an angle of approximately 60 degrees and no more than 90 […]