The new bypass of Doetinchem has to alleviate traffic from the centre of the city. This bypass will be constructed in a fragile natural region called “de Zumpe”, which brings along specific demands and complex water management. Flora and fauna have to be kept natural land the swamp-like area also brings the necessary structural challenges. In addition, the bypass is also build through the old industrial zone of “ESBRO”, where the sanitation might negatively influence the fresh water reserve and soil conditions.
Bartels Infra was contracted by Van Sijker Infrabouw to supply the overall- and structural- engineering fort his project. Our contribution to this project was the optimization of construction, with the aforementioned issues the area brings.
We supplied for example a solution for anchoring the tunnel, which will else float upwards because of the high amount of groundwater. Moreover, there is a limited capacity of foundation tie rods. The already existent sturdy layer of sand is relatively thin and shows unexpected deformations, which strongly influence the strength of the foundation. The solution is found in tunnel-weight, a planning grid of the tensile elements and by mapping the load in different phases. The definitive choices were developed with the responsible parties and their advisors.
As is also involves an underground rail crossing, more intensive requirements will be utilized to the deformation and movement of the surface during the entire lifespan of the construction. Especially the construction phase requires an extensive analysis. The road surface has to be broken in and has to be temporarily supported temporarily and fixated. Due to the sharp crossing angle, the fixating of the rail surface is not easy. A smart temporary support structure with additional steel reinforcements allowed working within the desired tolerances.
The construction is designed future-proof. Currently only two lanes are utilized. However, the construction allows having 4 lanes, 2 on each side. This design mentality is mirrored over the railroad crossing, which is designed to allow higher train-classes to use this crossing. The construction is also supplied with the appropriate grounding.
Next to the railroad crossing, a small Ecoduct is constructed. The Ecoduct is designed to be maintenance free and future proof, where the walls, floors and roof are poured monolithic. With this design bearings, which otherwise had to be replaced in future years, will not have to be replaced because of the monolithic poured concrete. This results in no to little maintenance for this construction, which in turn allows a sustainable and future proof bypass to be constructed. A beautiful piece of engineering we can be proud of!