Anchoring Systems

Anchoring Systems

How are Broadwell Air Domes anchored? What are your options? Unlike traditional buildings, an air dome anchoring foundation is designed to handle the uplift and horizontal forces acting on the dome versus the weight of  a building.  Learn more below!

Dome Anchorage Options

Your dome foundation will take into consideration your local wind load and snow load requirements. Foundation design/engineering, as well as dome structural, mechanical, and electrical engineering are all stamped by our engineers who are licensed in all 50 states and 42 countries. 

*Question to Consider: What kind of soil/material will be underneath your dome? Professional geotechnical soil testing is usually required to determine the load bearing capacity of your soil.

air dome anchorage foundation grade beam

Grade Beam Concrete Footing

Most often used for permanent applications, many Broadwell domes have anchoring systems that consist of a grade beam concrete footing with embedded bolts, to which the dome is attached using steel angle irons. The width and depth of the footing will depend on the anchoring forces required for your specific dome, and the holding capacity of your soil. Given recent increases in building material costs, including concrete, a hybrid grade beam and angle-iron foundation may be preferable, as the design on the left shows. Note: this is an example design. Your design may be different. 

Stem Wall

Domes can be attached to walls, as well as to buildings. Building codes may required the dome to be on a raised stem wall, depending on its size and use. Our engineers can design the stem wall and the dome attachment mechanism. 

air dome wall attachment

Earth Anchors

Earth anchors come in various designs, but for Broadwell Air Domes they are typically a steel arrowhead connected to a reinforced cable that is driven as deep as 5' into the ground. This cable is then anchored into a smaller concrete footing, or to an angle iron. Knowing soil composition is necessary with this option, as the anchoring load of each earth anchor depends on the type of soil it is being driven into. Obtaining a geotechnical report from professional soil testing may be required. For example, one of our earth anchors may have a anchoring capacity load of 5,000 lbs when anchored into hardpan/asphalt. The same earth anchor may only have an anchoring capacity load of 600 lbs when anchored into loose, fine uncompacted sand.

air dome earth anchor

Cement Blocks / Jersey Barriers

This option is also typically used for mobile or temporary dome applications. Cement blocks (or jersey barriers) are used on the outside perimeter of the dome to weigh it down, or some of our clients have created custom cement blocks with bolts embedded to them, to which the dome is attached. Some of our mobile "event dome" clients have used cement "bin blocks" to weigh the dome down. 

Jersey type barrier 1

Sand or Water Ballast System

This option is typically used for mobile or temporary dome applications. Your dome would be weighed down with large ballast bags filled with the required amount of sand or gravel. Our engineers have also designed an anchoring system with a large reinforced tube or bladder of water around the perimeter of the dome. These can be used for smaller domes (typically below 35,000 square feet).

Steel Plated Box Filled with Gravel

This custom anchoring system was developed by Broadwell engineers for a client who owned a gravel pit and wanted to use gravel in their anchoring system.

Custom!

The goal of an air dome anchoring system is to create a consistent and strong anchoring force load. As shown above, this can be achieved in a variety of ways. Our team of 50+ employed engineers are the most innovative in the industry. We are constantly developing new and innovative ways to anchor our domes.

Dome Components

Pool Dome - Striped Skylight

Our domes are comprised of various mechanical elements. Click on the following links to learn more about what pieces make up our domes: