Today's modern bridge construction projects face totally new challenges. The public, the regulators and the authorities demand structures that are cost effective during their planning, execution, lifetime and dismantling. This translates into a higher relevance of the life cycle costs, and the so-called external costs associated with the execution and maintenance of the structure.

Bridge DesignExtract 1 of the video. @ArcelorMittal Long Products

Politicians, building regulators and other decision makers face the challenge of choosing sustainable bridge designs, for which the price of the construction is not the only variable, but one of many, such as construction time, social impact (during construction and operation), environmental impact, maintenance, etc. Current procurement practices tend to favour the most economical bridge design. Unfortunately, today's awarding practice often results in cheap bridge designs with low construction cost, disregarding expenses due to operation and maintenance, and ignoring the impact that longer construction times have on traffic conditions and the public.

Approximately 80% of the bridges that comprise the European road network can be classified as small or medium span structures of less than 50 m. When performing a very simple analysis, reinforced concrete and prestressed concrete appear to be the most cost-efficient solutions available. On the other hand, it is widely accepted among the construction industry that composite structures are the best solution for spans larger than 50 m, when height restrictions apply, or if shorter construction periods are required [1]. In recent years, numerous studies and examples have demonstrated that composite bridges provide cost effective solutions for shorter span structures even if these conditions do not apply.

Ellerholzrampe BruckeEllerholzrampe Brücke, Deutschland, ©ArcelorMittal Spundwand

The right choice of bridge design

For two-span road bridges with an average span and traditional abutments, manufacture of the abutments accounts for approximately 40% of total manufacturing costs of the bridge without temporary pit walls required; this rises to roughly 55% when temporary retaining walls are required for the construction [2]. In these situations, abutments with sheet piles are a smart alternative to traditional construction, as the sheet pile can take over both functions, serve as retaining walls, and as permanent load-bearing structural elements [3].

Steel sheet piles are always highly cost-effective whenever the construction of the structure requires additional temporary pit walls. This is the case when a change of ground level is to be accommodated during the construction stage, when building below the groundwater table and when the excavation pit needs to be protected against flooding. Further, use of steel sheet pile abutments instead of abutments with temporary buildings pit walls, can reduce total construction time by a minimum of 10% [5].

Grafiken CostsBenefits of steel solutions in bridges

There are also significant advantages when building the bridge deck using composite sections that are manufactured based on hot-rolled, high strength steel sections. To reduce the space needed for the construction site, these composite elements can be partially prefabricated offsite and supplied to the construction site as load bearing elements during construction and the final stages. In addition, it is possible to install the prefabricated bridge girders during brief shut down periods of the crossed road, avoiding major disturbances to commuters, allowing traffic to circulate below the bridge while any subsequent work is safely carried out above the carriageway.

ZweifeldbruckeZweifeldbrucke, Deutschland

The hidden costs of traffic congestion

Not only the direct building costs must be considered, but also the economic costs generated by delays, increased fuel consumption and air pollution caused by traffic congestion during the bridge's life cycle. Congestion has a massive economic impact. According to data published in 2016, the average cost per hour that a European passenger spends stuck in traffic is estimated at 20€ [6].

Choosing a design with a reduced construction time, and with low maintenance requirements, becomes a priority when a global analysis contemplates the cost of the external effects. Especially as one of the main reasons for slow moving traffic, the construction sites, are going to grow in number in the coming years, as the infrastructure investment in Europe is foreseen to increase.

The study

Bridge Abutment ArcelorBridge abutment, Luxembourg, ©ArcelorMittal Photo Library
Nowadays, some feasibility studies analyse the operation and maintenance costs, but most of them disregard the economic impact of external costs generated by delays, increased fuel consumption and air pollution caused by traffic congestion during the construction, maintenance and repairs of a bridge design life.

A case study, performed by the Karlsruhe Institute of Technology (KIT), assesses all associated costs and performance of a traditional concrete bridge versus a bridge whose abutments are constructed using steel sheet pile sections. This comparison is performed for a two-span superstructure with spans of 22,50 m and a superstructure width of 11,50 m accounting for a standard crossing of a national road over a 3-lane motorway with an average daily traffic (ADT) of 70'000 vehicles:

Option 1: Steel Sheet Pile abutment (SSP abutment)
  • 16 m long piles on the front wall
  • 13 m long piles on the lateral wings.
Option 2: Reinforced concrete abutment (RC abutment)
  • 4 piles per abutment plus 2 per wing wall
  • 10 m length concrete piles of 90 cm diameter.
Choosing a bridge designed with steel sheet pile abutments and a composite deck built with steel sections leads to global cost benefits such as:
  • 7% reduction on construction costs
  • 3.5% reduction on lifecycle costs over 100 years lifetime (based on a real discount rate of 2%)
  • Up to15 % reduction in the economic impact of the external effects during the service life of the structure.
Bridge-Building Technologies of the Future: Fast, Efficient and Economical in the Long Term

Composite steel bridges with steel sheet pile abutments are robust structures that require limited maintenance and repairs due to use of state-of-the-art corrosion protection techniques, which ensure 100-year design life without need to replace any component.

Steel sections offer the advantage of easy dismantling, recovery and recycling after the bridge service life, ensuring that no residues remain in the soil, and adding a valuable contribution to the circular economy. This helps to prevent abuse of natural resources.

References:
  1. Friedrich H.: Aktuelle Herausforderungen und zukünftige Entwicklungen im Brückenbau im Bundesfernstraßennetz. Stahlbau 87 (2018), issue 6.
  2. Schmitt V., Seidl G., Vogel C.: Untersuchungen zum verstärkten Einsatz von Stahlverbundkonstruktionen bei Brücken kleiner und mittlerer Stützweiten. P629 Forschungsvereinigung Stahlanwendungen e.V., final report, 2006
  3. Grundbau-Taschenbuch. 8th edition, Ernst & Sohn, 2018
  4. RI-WI-BRÜ – Richtlinie zur Durchführung von Wirtschaftlichkeitsuntersuchungen im Rahmen von Instandsetzungs-/ Erneuerungsmaßnahmen bei Straßenbrücken, BMVBS, 2007
  5. Zinke T.: Neue Brücken braucht das Land. Frankfurter Allgemeine Zeitung Verlagsspezial / Zukunft Stahl / 30 November 2017.
  6. Zinke T.: Nachhaltigkeit von Infrastrukturbauwerken – Ganzheitliche Bewertung von Autobahnbrücken unter besonderer Berücksichtigung externer Effekte. Karlsruhe: KIT Scientific Publishing, Dissertation 2016. Available online http://www.ksp.kit.edu/download/1000053695
Our steel builds bridges

Hot-rolled sections and sheet piles produced by ArcelorMittal: our contribution to pioneering projects.
Subgrade makes the formation level of the road crust. The material specifications of subgrade material are therefore more demanding than the soil used in general fill or embankment. In some construction projects, it becomes difficult to get the required subgrade

Read more ...

Atasi Das, Assistant Vice President, G R Infraprojects, explains the concept of the Perpetual Pavement in India’s expressway constructions and its practical implementation with due consideration of layers, materials, and thicknesses

Read more ...

Dr. Rakesh Kumar, Senior Principal Scientist & Pankaj Goel, Senior Technical Officer, Rigid Pavements Division,CSIR-Central Road Research Institute (CRRI), New Delhi, give information on the Performance of Curing Compounds in Strengthening

Read more ...

The construction and maintenance of roads with flexible pavements in very cold regions where annual temperatures range between +30oC to -35oC has got its own challenges. The bitumen in the asphalt layer becomes hard at such low temperatures

Read more ...

The Bundelkhand site team achieved yet another feat on 15 Jan 2022 by completing 13 deck slabs of varying types in just 46 days. Therefore, it is a demonstration of exemplary display of overall project executing capabilities

Read more ...

Er. Devjyoti Paul, Project Manager & Er. Harpreet Singh, Chief Project Manager, B&SEC, share the technical and construction features of three bowstring girder ROBs, recently constructed under Package I & III of Purvanchal Expressway in the state of Uttar Pradesh

Read more ...

Use of Extruded Polystyrene Sheets (XPS) in the construction of the Zojila Approach Road has been especially effective as XPS is the most suitable, convenient, and cheaper solution for mitigating frost action on pavements, increasing the life of pavements

Read more ...

The Indian road network is the second largest globally, with a length of around 63.86 lakh km. The outbreak of the virus towards end-FY20 had created panic globally, leading to the temporary suspension of economic activity

Read more ...

Roads and Railways boost awards; tenders up marginally Overall tendering grew 5% YoY during H1FY22 Awarding activity grew at a 2-year CAGR of 22% in H1FY22 Infrastructure credit near all-time highs

Read more ...

There are many challenges being faced by the highway sector such as ensuring availability of construction materials and machinery, timely completion of projects, availability of trained human resources

Read more ...

Practical Recommendations for Construction of Longitudinal Joints in Hot Mix Asphalt (HMA) Pavements Rajib B. Mallick, Ralph White Family Distinguished Professor, Civil and Environmental Engineering, Worcester Polytechnic Institute (WPI), Massachusetts, USA, and Veeraragavan

Read more ...

Plant and Equipment Determine Quality of Road Construction Road Infrastructure projects are time constrained; early completion of project entitles rewards while delays attract penalties. The plants and equipment being used determines the quality of the road

Read more ...

Designing roads and highways efficiently with the right materials will help achieve optimum construction cost, lower maintenance, and reduce life cycle costs. Ash from coal-fired thermal power

Read more ...

Rodic Consultants has emerged as a leader in the infrastructure consulting space with state-of-the-art engineering solutions, and a proven track record of timely completion of projects across sectors

Read more ...

Readymade Kandhal Pothole Patching Mix was adopted as Indian Roads Congress (IRC) Standard Specification IRC: 116-2014 for Readymade Bituminous Pothole Patching Mix Using Cut-Back Bitumen. All concerned

Read more ...

The Bundelkhand Expressway is a 296-km long, 4-lane wide (expandable to 6 lanes) access-controlled expressway in the state of Uttar Pradesh. It will connect Gonda village in Chitrakoot district with Agra–Lucknow

Read more ...

This case study briefly discusses the planning, design and construction of Package 3 of the Purvanchal Expressway. Package-3 of the Purvanchal Expressway is a 41.7km long section of the 340.82km long

Read more ...

Since the 1980’s billions of dollars have been invested in developing methods to make pavement design and construction more sustainable through the re-use of existing resources. This includes insitu recycling and

Read more ...

India has the second largest road network in the world, spanning a total of 5.89 million km, transporting 64.5% of all goods in the country. Nearly 90% of India's total passenger traffic uses the road network to commute

Read more ...

India generates nearly 26,000 tonnes of plastic waste every day, making it the 15th biggest plastic polluter globally. Discarded plastic waste litter the country’s roads, rivers and also form huge mounds in garbage

Read more ...

×
Sign-up for Free Subscription
'India Construction Week'
Weekly e-Newsletter on Construction Industry
Get the latest news, product launches, projects announced / awarded, government policies, investments, and expert views.