Soil and rock anchors are tension elements that derive their resistance to load through cement grouting or bearing in soil or rock. They can be used in temporary or permanent applications to support retaining structure or resist foundation uplift and are often prestressed to control deflection of the structure that they are designed to anchor. A variety of proprietary and commodity systems can be used to construct soil and rock anchors. Consequently, it can be advantageous to specify soil and rock anchors in a manner that contractor-proposed alternative systems can be entertained or to delegate design to the contractor through a performance specification.
The specification and design of soil and rock anchors is an interdisciplinary problem. Geotechnical engineering capabilities are required to adequately understand the subsurface conditions and evaluate the resistance provided by soil or rock. However, structural engineering knowledge is needed to properly specify the tiedown type for the demands of the structure and to properly detail the connections.
Richard J. Driscoll, Consulting Engineer (RJDCE) specializes in these sorts of problems and has provided both recommendations for soil and rock anchor systems, as well as detailed design for construction. RJDCE is independent of anchor system manufacturers and can provide technology-neutral recommendations, allowing the details of the anchor system to be selected according to the structural demands, subsurface conditions and installer preferences.