Optimised Geogrid-Reinforced Bridge Abutments for Sustainable Bridge Construction

Traditional reinforced concrete bridge abutments are durable but often come with extended construction times and potential differential settlement issues. Geogrid-reinforced soil structures offer an efficient alternative, reducing both construction time and costs. By incorporating Secugrid® geogrids, loads are distributed evenly, increasing ductility and minimising settlement differences. This method allows for the use of locally available materials, is 100% recyclable, and can reduce CO₂ emissions by up to 85%. A notable example is the construction of the Prüm Bridge in Minden, where this innovative approach was successfully implemented.

Solid bridge abutments made of reinforced concrete have been used in bridge construction for many decades. These are designed to be robust and low-settling. However, these advantages are offset by the technical and economic disadvantages of the in-situ concrete construction method, such as the comparatively long construction time and the possible differences in settlement between the almost rigid abutment and the adjoining, settlement-friendly dam structure. This can lead to a lack of ride comfort and damage to the expansion joint structures.

  1. Geogrid Secugrid 120/40 R6 (SP)
  2. Geogrid Secugrid 120/40 R6 (ST)

The international experience gained over more than three decades with the construction of plastic reinforced earth (KBE) allows this construction method to be used today as bridge abutments. This offers both economic and ecological advantages over conventional construction methods. By using KBE structures as earth pressure absorbers behind load-bearing components, solid concrete structures can be made significantly slimmer and more cost-effective. The “geogrid floor” composite body distributes the applied loads over a larger area, which leads to a high ductility of the structure. This minimizes differential settlements between the embankment fill and the bridge abutment.

In Japan, the high ductility has led to KBE constructions being established as the standard construction method for high-speed railroad lines due to their extraordinary robustness in the event of earthquakes. When suitable outer skin systems are used, the KBE construction retains its robustness even as a result of impact loads or in the event of fire. It can be easily repaired in the event of damage. The almost 100% recyclability of the construction and the approximately 85% reduction in greenhouse gas emissions compared to a technically equivalent steel-reinforced concrete wall speak for the ecological advantages of this construction method.

In summary, geogrid-reinforced bridge abutments in KBE construction offer the following advantages over conventional reinforced concrete construction methods:

  • Minimization of differential settlements between bridge abutment and embankment fill through high ductility and increased load distribution in the fill soil

  • Use of locally available soils or recycled building materials possible

  • High adaptability to the surrounding landscape thanks to variable outer skin design

  • Quick and easy dismantling of temporary structures

  • 100% recyclability of the construction

  • Reduction in construction time

  • Reduction of the time spent on the road

  • Reduction in construction costs

  • Reduction of CO₂ emissions

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