Two innovative anchoring techniques highlighted

High 5 Solutions (H5S) is a specialist in sonic installation of grout anchors and anchor piles, applying this innovative technique to a variety of work. The company has now been active in Dutch foundation engineering for ten years and can be proud of an impressive portfolio of projects. In early 2025, this festive milestone was celebrated with a grand party at the company's premises. The anniversary year is a fitting time to reflect in GWW-Bouwmat on two leading techniques that contribute to innovation in the foundation industry.

Sonic removal of grout anchors

Sheet piles are often provided with grout anchors to stabilize the structure. Many of these sheet pile walls have a temporary function, and so do the associated anchors. Although techniques for removing temporary anchors have existed for some time, there are disadvantages to doing so. For example, steel elements are often left behind in the subsurface, hindering future work. In other cases, the released anchor material is not suitable for reuse.

They think that's a waste at H5S. That's why the company developed a method to sonically remove grout anchors. This technique offers a solution to the aforementioned disadvantages. Self-drilling grout injection anchors are used that can be completely removed from the ground afterwards. As a result, no anchor rods are left behind in the soil. Thanks to the modular, self-drilling anchor system, the anchors can also be disassembled upon removal, making the materials reusable.

The very high sonic frequency of over 150 Hz causes the anchor rods to loosen from the grout body. The drill head of the anchor is set in motion again and helps loosen and pulverize the grout plug. H5S has successfully removed thousands of anchors this way. This technique not only contributes to a more efficient construction process, but also fits well with the industry's shared sustainability goals.

Underwater anchoring

When the lifespan or capacity of an existing or new quay needs to be increased, underwater anchoring can offer a solution. Since 2018, H5S has been working on the development of this technique, in cooperation with the Port of Rotterdam Authority, among others. A total of three market parties developed an underwater anchoring system together with the Port Authority. H5S demonstrated the operation of its anchor system during a test project in Rotterdam's Seinehaven.

High 5 Solutions' underwater anchoring system is based on four principles:

• Excluding human actions underwater as much as possible;
• Applying sonic drilling technology to minimize impact on the environment;
• Limiting leaching of soil through application of sonic drilling technology;
• Using existing calculation methods and anchor systems to ensure structural safety.

The starting point for H5S in its development was not to deviate from the tried-and-true concept by which the company applies anchors above water. By doing so, they avoid becoming entangled in all kinds of new standards and guidelines. The self-drilling anchor system combined with sonic drilling technology has already proven itself above ground. For underwater installation, however, there is an important difference: where normally several process steps are required - such as burning holes, mounting anchor chairs and drilling in anchors - the underwater anchor is installed as a single unit. In this case, the broker of the sonic drill moves into the water and the hole in the sheet piling, the anchor chair and the anchor are installed in one pass. The test project in the Seinehaven has been successfully completed, and we look forward to using this technique in future projects where underwater anchoring can be a solution.

Future

Even in a market that is constantly changing, H5S continues to evolve. In the coming years, the company will take on some great challenges that will contribute to cleaner and more sustainable anchoring projects. In doing so, improving quality remains a continuous focus. What always remains paramount: safety and job satisfaction for the people in the construction industry.

In all these areas, H5S works closely and pleasantly with its clients, and certainly also with the Nederlandse Vereniging Aannemers Funderingswerken (NVAF), in which many fellow foundation companies are represented.