DYWI® Drill Hollow Bar Receives Building Authority Approval for Permanent Use

With the DIBt construction approval, the proven micropile system can now also be used for permanent projects in specialist foundation engineering. For construction companies, planners, and authorities, this means more planning security and flexibility.

Munich, Germany – November 2025 – An important step for DYWIDAG and its customers: The DYWI® Drill Hollow Bar System has now been officially approved by the German Institute for Building Technology (DIBt) for permanent use in specialist foundation engineering. Until now, the system was only approved in Germany for temporary measures. The General Construction Approval (aBG) with the number Z-34.14-255 confirms that the DYWI® Drill Hollow Bar System meets all requirements for permanent use. “The DIBt approval is a decisive step for the German market. It gives our customers the assurance that our solutions have been tested to the highest standards,” says Michael Glassl, Vice President Sales Geotechnics Germany, Netherlands, and Finland. Construction companies and planners benefit from a greater selection of comparable, approved systems. This increases flexibility in project design and simplifies approval processes.

Reinforcement and Drilling Tool in One

The DYWI® Drill Hollow Bar System is a self-drilling micropile system that combines drilling tool and reinforcement in a single element. During the drilling process, the hollow bar is grouted with cement suspension and then remains in the ground as a load-bearing component. This technique enables particularly efficient and flexible application—especially in confined spaces, difficult soil conditions, and time-critical construction projects. Typical areas of application include slope and embankment stabilization, excavation pit support, foundation reinforcement, retaining walls, tunnel construction, and infrastructure projects. Wherever the subsoil is challenging or space is limited, the system offers a reliable solution.

Proven System

For around 25 years, the DYWI® Drill Hollow Bar System has proven itself in numerous construction projects. In Germany, for example, DYWI® Drill Hollow Bars of type R32-250 were used for slope stabilization during the renewal of the Aura-Euerdorf line. DYWI® Drill soil nails were also used to stabilize a railway embankment during the renewal of the railway bridges over the Wätern and Aller rivers in Verden. Another example is the renaturation of the Schondelle river in North Rhine-Westphalia, where DYWI® Drill Hollow Bars of type R32-280 were installed. Internationally, the system has also proven itself: In France, it contributed to the restoration of the historic L’Hôtel de la Reine in Nancy. In Poland, DYWI® Drill Hollow Bars made an important contribution to securing the Speicherinsel in Gdansk and were used in the major S1 expressway project between Kosztowy and Bielsko-Biała.

About DYWIDAG

Since its founding in Germany in 1865, DYWIDAG has been a pioneer in engineering, ensuring that structures are built and maintained safer, more stable, and smarter. Today, DYWIDAG is represented in over 40 countries and employs more than 1,500 professionals. The company specializes in prestressing, geotechnical, stay cable, and concrete systems in various markets. By combining deep local expertise with global competence, the company ensures structural integrity that stands the test of time.

Media Contact

Birgit Carl European Marketing Manager birgit.carl@dywidag.com +49 172 245 9441 www.dywidag.com