Noise protection embankment system for freight yard

Situation

A former railway site in central Cologne was to be developed for residential use. In order to meet the relevant noise protection requirements, it became necessary to construct a noise protection embankment parallel to the heavily used Cologne–Aachen railway line. Lasting noise protection required a structure up to 11.2 metres high over a length of approximately 500 metres. From an urban ecological perspective, the embankment was to be as fully vegetated as possible on the residential side, while for reasons of immission control, a highly absorbent face was required on the railway side. A particular challenge was posed by the soft, non-load-bearing soils extending to depths of up to 8.0 metres.

Solution

As the optimum solution for all geotechnical, design and regulatory boundary conditions, a noise protection embankment system made of geogrid-reinforced soil (geosynthetic-reinforced soil system: GRS) was constructed, featuring a sound-absorbing gabion facing towards the railway line, a naturally vegetated facing towards the residential development, and an additional sound-absorbing gabion trapezoidal top section. The noise protection embankment was founded on vertical load-bearing elements spanned by geotextiles.

Advantages

• High construction speed
• Low construction and maintenance costs
• A system offering long-term safety for construction on low-bearing-capacity soils
• The ductility of the structure enables a long service life of more than 80 years
• High sound absorption of ≥ 8 dB (highly absorbent)
• A natural-looking and landscape-integrated facing towards the residential development
• An optimum solution for the urban ecological framework conditions
• Monitoring and integration can be accommodated through measurement technology