Innovative dike reinforcement in Neer

The Limburg Water Board is building and strengthening dikes along the Meuse River. The dyke reinforcement in Neer is special thanks to the glass barrier. This should protect residents and the hinterland against high water. The tests taking place this fall should show whether this innovative construction works.

Due to climate change, rivers like the Meuse are going to discharge more and more water. Because most dikes cannot withstand this, many are now being addressed. The national, provincial and municipal governments have therefore joined forces to strengthen and relocate dikes. Neer in Limburg must also be protected from high water according to the new standards by the end of 2020.

Eighty centimeter high transparent glass panels

Strukton Civiel Zuid is realizing the dyke reinforcement and, together with client Waterschap Limburg and hydraulic engineering firm Van den Herik, has drawn up a design and plan of approach. Twan van Erp, project manager at Strukton: "This includes raising the 2,100 meters of the existing dike. Of that, 1,600 meters will be formed by a green dike, which will be raised and reinforced with clay. The bike path that runs over it will also be renewed. The other 500 meters long section lies at ground level and consists of a concrete retaining wall. We are going to replace it and raise it to meet water safety standards. Over a length of 80 meters, where there are houses, we are going to install 80-centimeter high transparent glass panels on the concrete retaining wall. Because these must be extremely strong, they consist of laminated glass a total of 8-10 centimeters thick, fixed in steel frames. Furthermore, we are going to fit three more passages (coupures) in this wall with new retaining devices."

The existing green dike at Neer will be reinforced and raised with clay.

Resident participation

Why was this unique and innovative glass solution chosen? According to Guido Toirkens, environmental manager at Waterschap Limburg, resident participation played an important role. "A group of residents with houses whose backyards border the retaining wall wanted to keep a view of the Meuse. That would otherwise completely disappear with a raised all-concrete retaining wall. Several information meetings and public participation sessions followed, with residents coming up with their own solutions. For both parties it was important to have a nicely designed barrier that fits in well with the landscape. For the water board, however, safety always came first. After studies by an engineering firm and a presentation by a renowned architect, support was gained and the glass barrier became the final compromise. An aesthetically sound, but never before applied and technically proven solution."

Field trials will take place this fall

Therefore, practical tests are taking place this fall at Deltares' test laboratory in Delft. In this 'Delta flume', the contractor is testing the effect of extreme waves on dikes at full scale. Van Erp: "The glass elements are put in there and the test must show whether the system meets the requirements. If the test is successful, implementation can begin in April 2020 when the high-water period (which runs from Oct. 15 to March 15) is over." Other requirements that must be met are that at least 90% must have transparent components with high image quality. Also, the glass wall must be vandal resistant, replaceable and expandable in height. Likewise, a signal must be issued should the glass break.