Today’s modern bridge construction faces new challenges such as the cost of building and maintenance and the time required for the planning and execution of the project.

This new video from ArcelorMittal describes how we build modern bridges with our innovative products and technologies: fast, efficient, sustainable, and cost-saving.

Two key elements are:
•    composite girders based on hot rolled steel sections of high-yield special steel grades
•    sheet piles as load-bearing elements leading to cost, time, and space saving during construction

Watch the video here: Our steel builds bridges video

ArcelorMittal Projects, ArcelorMittal Europe – Long Products Sheet Piling, and Global R&D participated in a project financed by the Dutch government to improve the design of dikes and keep the Netherlands safe from flooding.

Exploring economical and innovative solutions for safety

The Netherlands is a low-lying country protected from the sea by dikes and dunes. For decades, dike reinforcements have been installed to keep the country dry and prevent floods from happening. Due to continuously increasing safety demands and loads, one third of Dutch dikes do not meet safety requirements.

Macro-instability is one of the most common causes. It can occur when a high water level pushes against the embankment. This causes saturation of the soil and loss of stability resulting in large parts of the dike body sliding away.

When there is a lack of space due to cultivation around the dike, reinforcements to prevent macro-instability are utilised. Dikes with steel sheet pile walls are very strong and do not have to be widened thus reducing objections from residents and time-consuming judicial procedures.

Given the Dutch safety challenge, the need for cost saving has risen over the last couple of years. The government is making a tremendous effort to search for innovations that will allow for the necessary cost saving.

Taking part in the governmental study team

To investigate how the sheet pile design standards can be optimised, the government decided to finance dike tests in Eemdijk in the province of Utrecht.

The tests focussed on gaining a better understanding of the interaction between the soil and the steel sheet piles. A team consisting of ArcelorMittal Projects, ArcelorMittal Sheet Piling, and the R&D department contributed to the design process. ArcelorMittal also provided GU8N and AZ26-700 sheet piles for the tests. They were produced by ArcelorMittal's sheet piling mills in Dabrowa, Poland and Belval, Luxembourg.

The choice of the sheet pile profile in combination with the steel quality was crucial for a successful test. All dimensions of the sheet piles were extensively tested to ensure an accurate mapping of the profile characteristics. Additional tensile tests were performed to determine the exact mechanical features.

This testing program was part of the Project Transcending Exploration Macro stability (POV-M)*, which is under the Flood Protection Program (HWBP)*. The tests even gained attention at the international level from the US Army Corps of Engineers to delegates from South Korea and China.

*The sheet pile tests were executed in cooperation with Waterboard Vallei and Veluwe, Deltares, Witteveen+Bos, Fugro, and ArcelorMittal.
**A cooperation between Rijkswaterstaat (The Ministry of Infrastructure and the Environment) and the water boards.

Test setup and process

At the Eemdijk test site, an oval shaped dike of 5m high, 60m long, and 40m wide was constructed in six months’ time. The dike was fitted with measuring equipment and was only used for this experiment which helped to increase knowledge of soil-structure interaction. After the tests, the dike will be completely removed. A total of three tests have been performed at the site with our sheet piles produced in Dabrowa and Belval.

Full Scale Test Green Dike: This part of the dike was constructed with a sand core and an outer cover layer of clay. The groundwater level inside the core of the levee was slowly raised to +2.80 metres, at which moment a sliding plane occurred and the dike collapsed. This test acted as a baseline measurement which was used as reference for the final test.

Pull Over Tests: Four different sheet pile configurations were installed 14 metres into the ground after which they were pulled over with a hydraulic cylinder. The objective was to see at which force level (with a maximum of 100 tonnes for AZ26-700) and which deformation the sheet pile wall would collapse. Additionally, the four configurations gave insight into the differences in the behaviour of a continuous wall and loose panels and between the elastic and plastic behaviour of the steel sheet piles.

Full Scale Test Blue Dike: This part of the dike was built similarly to the green dike apart from the reinforcement, which was over 60 metres with GU8N sheet piles. These piles were placed as triplets and staggered with lengths of 18 and 9 metres. This test was a combination of the above-mentioned tests and was the main test of the research.

A 2-metre-deep ditch was dug at the bottom of the blue dike. The groundwater level in the dike body was slowly raised and the filling of the water basin behind the levee was carried out over time. This led to a water level at the crest of the dike located at +5 metres. In addition, seven containers filled with water were placed on top of the dike, creating an extra load of 40 tonnes per container. Despite the combination of the huge loads, the steel sheet pile reinforced dike refused to give way.

By infiltrating the landward slope of the levee and lowering the water level in the ditch, the dike finally collapsed. Two million litres of water flowed out of the basin into the hinterland highlighting the success of the tests.

Saving 20-30% of steel

The dike, reinforced with steel sheet piles, finally collapsed but only after putting an extreme load on it; not collapsing the dike would have resulted in a less successful test.

Results of the different tests were in line with realistic predictions which are even more favourable than current calculation rules. This concludes that steel sheet pile walls are an extremely strong and practical solution for dike reinforcements.

Existing dike reinforcement projects cost an average of 15 million Euro per kilometre of dike. It is estimated that with these updated design rules, 20-30% of steel can be saved in new projects. With this cost savings, it is anticipated that the market share of the “innovative” steel sheet piles will increase in future dike reinforcement.

Text: ArcelorMittal Europe Communication

Copyrights: © POV Macrostabiliteit

In the last years, severe floods caused by storms and heavy rains have increasingly shaken the whole world and have shown that flood protection continues to be an important topic. In order to minimize flood damage, significant investments are required in this area – and steel sheet piles offer an efficient solution for flood control and riverbank protection.

Efficient flood protection systems with sheet piles

In order to establish an efficient anti-flood system, apart from creating a polder system with flood plains, land reclaimed or marshes, it is necessary to take some integrated activities within the range of the environmental development and construction strategy. It is essential to build a relationship between modern technology solutions and the potential of the natural environment itself.

The implementation of steel sheet pile jagged walls is the safest and the most cost-effective solution. The sheet piles are the best answer for building and reinforcing flood dikes, ditches, etc. Their high tightness coefficient is well-known and tested in practice. The ArcelorMittal sheet piles, either hot or cold rolled, are an appropriate and optimal solution for the problem. Self-propelled high frequency vibrators and hydraulic machines are used for the sheet pile caving. This way there is no environmental damage.

A short installation time allows the use the sheet piles just before the flood arrives. It is possible to use them in many ways, taking into consideration the evaluated and real loads.

Steel sheet piles offer numerous benefits in flood protection

1. Sheet piles can seal and stabilize both existing and new flood dikes. They prevent tides and stabilize the structure of flood dikes. The combined wall is an impassable barrier for animals and tree roots and prevents landslides. The part of the wall seated into the ground is corrosion-resistant — under normal conditions it is assumed that the wall thickness decrement reaches 0.03 mm per year, 1.5 mm per 50 years (source: Eurocode 3. Design of steel structure. Part. 5 Piling).

2. Another benefit of using sheet piles within the range of flood protection is the material as itself: Steel is homogenous, flexible, plastic and safe for the environment. The material meets the requirements of well-known standards (EN). Steel is 100% recyclable — it is 100% "ecological" material.

3. Steel jagged walls are provided as ready-to-use products for immediate application. Some construction transformations like replacement, caving depth increase, sheet piles joining, may be operated at any time. It is possible to use various sheet pile types within the scope of the given project and to join them in order to make the structure unbroken and optimize the investment costs.

4. Sheet piles are one of the solutions for ditch (flood dike) tides. Whereas other construction materials yield easily, it is impossible to break a sheet pile structure. The ArcelorMittal sheet piles, used in anti-flood structures all over Europe, prove that they are a fast and cost-effective solution.