Structural anchoring and underpinning using grout-bonded elements is a common approach for today’s Civil Engineering community.  These high capacity, drilled & grouted elements provide the critical load transfer mechanism in a cost-effective, robust design approach.  The anchoring and micropile industries continue to mature and add new products and approaches as the needs of the marketplace are recognized and addressed.

One such advancement is the increased specification of hollow bar elements.  With a solid bar or strand anchor the installer must initially provide a hole in which the anchor can be placed prior to grouting.  In certain ground conditions, where cohesionless soils are likely to cause a collapse in the hole, a hollow bar element is often considered as a cost-effective and production-efficient option in lieu of cased drilling.  These simultaneous drill & grout hollow bars maintain an open hole, increase job site efficiency, assist in meeting tough schedule requirements, and their use has been increasing dramatically over the past 2 decades.

In this webinar, we will discuss details unique to the hollow bar system.  We will cover recent research conducted through the Federal Highway Administration, emergence of the system in governing specifications, and discuss what seems to be the main issue with permanent hollow bar anchors: long-term durability.