"Design of a road bridge in accordance with integral evaluation criteria”

SSF with partners wins 2nd prize of the idea competition of the Bavarian Chamber of Engineers

To gain awareness and reinforce the subject of sustainability in the field of bridge design, the Bavarian Chamber of Engineers – Civil launched the idea competition “Design of a road bridge in accordance with integral evaluation criteria”.

Aim of the competition was to develop bridge concepts that, in addition to fulfilling traditional quality criteria of an optimum design, satisfy economical, socio-cultural and last but not least ecological evaluation criteria over the whole lifecycle, in view of high sustainability for the next generation and at the same time highest possible economic benefit.

The integral approach of a sustainable bridge concept comprises the following evaluation criteria:

Ecological quality

  • criterion 1: greenhouse gas potential/production
  • criterion 2: greenhouse gas potential/lifecycle – maintenance – renovation - demolition
  • criterion 3: greenhouse gas potential by traffic congestion due to maintenance works during lifecycle (incl. costs by CO2 E)
  • criterion 4: risks for the local environment

Economical quality

  • criterion 1: production costs (incl. CO2 E costs of main building material)
  • criterion 2: lifecycle costs – maintenance – renovation – demolition (incl. CO2 E costs)
  • criterion 3: external costs by traffic congestion due to maintenance works during lifecycle (incl. CO2 E costs)

Socio-cultural quality

  • criterion 1: design of structure and integration into the environment
  • criterion 2: user-friendliness

Technical quality

  • criterion 1: structural quality
  • criterion 2: maintenance and renovation-friendliness
  • criterion 3: demolition possibility, recyclability, demountability

SSF Ingenieure and his team convinced the jury with the design of an innovative composite prefabricated elements bridge and won the 2nd prize of 11,000 euros.

Participants

SSF Ingenieure AG, Munich
Hugger und Rampp Architekten, Munich
Prof. Schaller UmweltConsult GmbH , Munich
Baugeologisches Büro Bauer GmbH, Munich

In addition to weather-resistant structural steel, the work distinguishes itself by an open gutter for longitudinal drainage and a finger joint with clamp gutter and large transverse inclination, as well as the development of a modular construction system, whose implementation entails only small risks for the local environment.

As load-bearing system of the 8-span, 369 m long bridge over the Isar a composite girder grillage with high degree of prefabrication was proposed. On air-tightly welded steel box sections as main load-bearing elements prefabricated reinforced concrete cross girders are pre-mounted, and between the cross girders a first composite is created on the upper chords of the steel boxes. On this already very stiff and stable girder grillage the carriageway, made of fully prefabricated reinforced concrete slabs without additional in-situ concrete, is assembled. The joints above the longitudinal and the cross girders are grouted in-situ and form the second composite of the composite steel girder structure.

The advantages of this bridge concept are the balanced ecological and economical quality (short construction time, small use of space for construction site, low production costs, simple demounting with recycling possibilities). The considerate construction process with an optimum prefabrication of the bridge superstructure reduces impacts on the environment (local flora and fauna as well as global warming) caused by the bridge to a minimum.