Pre-stressed Rock and Soil Anchor Design and Construction Fundamentals-Pre-stressed Rock and Soil Anchor Design and Construction Fundamentals

Video Transcription

Video Summary

The Post-Tensioning Institute hosted a September webinar focusing on rock and soil anchorage fundamentals, a highly requested topic. Moderated by Kyle Boyd, chair of the education committee, the session featured expert speakers Andy Baxter and Nate Witter, both heavily involved in the industry’s DC35 committee. Andy covered design fundamentals, explaining the components of ground anchors—such as the pre-stressing steel (strand or bar), grout, encapsulation sheath, anchorage hardware, and corrosion protection—and typical applications like earth retention walls and dam tie-downs. He highlighted the importance of active, pre-stressed anchors for immediate load-bearing and long-term durability. Key design considerations include site geology, drilling conditions, load capacity, and corrosion protection tailored to service life and soil aggressivity. Nate focused on the construction side, detailing equipment selection, drilling techniques, and installation processes. Using examples, he described various drill rigs, tooling for rock and soil conditions, grouting methods, and corrosion protection practices. They stressed the importance of precise borehole alignment and monitoring during drilling and installation for reliable anchor performance. Q&A addressed topics like rig size and productivity, service-level versus ultimate design approaches, and grout mixture enhancements for corrosion resistance. The webinar emphasized practical integration of design and field expertise, offering continuing education credits. Upcoming webinars will cover slab-on-ground evaluation, AI applications in post-tension design, and repair techniques, responding to continuing industry needs. Overall, the session provided a comprehensive overview bridging theory and practice in ground anchor design and construction.

Keywords

Post-Tensioning Institute

rock anchorage

soil anchorage

ground anchors

pre-stressing steel

earth retention walls

dam tie-downs

drilling techniques

corrosion protection

continuing education