Second lock Eefde for better accessibility Twente canals

The current Eefde lock, in the Twente Canal just after the IJssel branch at Zutphen, is facing a capacity problem. In order to meet the expected growth in waterborne transport, the lock will be expanded with a second lock chamber, suitable for more heavily loaded vessels, on behalf of Rijkswaterstaat. That second lock chamber will also ensure a less vulnerable situation in case of maintenance, calamities or problems arising at low water levels.

The main contractor is 'Lock to Twente' (L2T), a partnership between Mobilis (civil engineering), Croonwolter&dros (technical installations) and TBI PPP. The combination began preparatory work at the end of 2017. The actual construction of the second lock chamber started in early 2018, and the first ships are expected to pass through the lock in mid-2020.

Voorbij Funderingstechniek installs anchors.

Technical challenges
The challenges within such a complete TBI project are mainly technical: connecting a complete structure to the waterway. An important reason for L2T to join forces with Voorbij Funderingstechniek, the versatile partner in bearing capacity. Harm Wammes, project leader at Voorbij Funderingstechniek, says: "With such complex works, it is crucial to sit down at the table with all parties at an early stage to share knowledge and expertise. This is not only beneficial in terms of execution, but also in terms of design. Using the existing principles, we started designing and optimizing to arrive at the best design."

Beyond Foundation Engineering.

Prepared for everything
"At the end of October 2017, we conducted preliminary pile driving tests," Harm continues. "This allowed an estimate to be made in terms of noise, vibrations, the insertability of the sheet piles and a more targeted prediction of productions. Thus, by optimizing the sheet pile design in the gully, a large amount of concrete could be saved. In January 2018, we started installing sheet piles with multiple machines. We invested heavily in our machinery last year: the Hitachi Sumitomo SCX 1000 was delivered in June 2018 and immediately deployed on this project. Pipe piles of up to 25 tons and sheet piles of up to 26 meters were duly installed with this. In total, we delivered and installed about 2,500 linear meters of sheet piling with corresponding anchoring and purlins for this project. During the installation of the sheet piling, we encountered obstacles, most likely construction debris from the current lock. As a result, the planks could no longer be placed at depth by vibrating, so we switched to 'post piling' with an IHC hammer. To minimize inconvenience to the surrounding area, a mobile noise barrier was deployed. In this way, like the Department of Public Works, we are striving to complete the project within the standards of environmental nuisance, sustainability and safety."

Install sheet piling with sound barrier.

Sustainable and safe
"We are focused on achieving technically and economically sound structures. Voorbij Funderingstechniek offers a total solution of design, project management and execution, paying attention to the environment and anticipating local conditions. The Eefde Lock Expansion project is ideally suited to further promote our TOVF safety program. TOVF stands for Trots Op Veilig Funderen, something that has a high priority for us. Besides the safety and health of our people, sustainability is also high on our list of priorities. The new lock chamber is designed to be energy-neutral. The technical installations are energy-efficient and practically all the sheet pile walls to be deployed are transported by water. The energy for operating the second lock chamber will soon be generated by solar panels. The current lock in Eefde is a monument and an icon in the landscape. Fortunately, I can say that the second lock will also be very special," Harm concludes.