BAUER Spezialtiefbau GmbH

How to dispose of waste? This question is not only the subject of discussion on a small scale, but also represents a challenge at the national level – especially when it comes to radioactive waste. The town of Krško in eastern Slovenia is the focus of a major project: the construction of a repository for low- and intermediate-level radioactive waste. The Slovenian Agency for Radioactive Waste Management (ARAO) has tasked a consortium led by Riko d.o.o. of Ljubljana, together with Kolektor CPG of Nova Gorica, CGP of Novo mesto and Kostak d.d. of Krško, to carry out the construction work. Trial operation of the facility is planned in 2028.

6,500 m² of diaphragm wall installed up to depth of 65 m

A key component of the project is the circular diaphragm wall shaft that was constructed by BAUER Spezialtiefbau GmbH. With a diameter of 32 m, a depth of 65 m and a wall thickness of 1.5 m, the structure extends over an impressive area of 6,500 m². To achieve this challenging task, the specialist foundation engineering experts used a BAUER MC 96 duty-cycle crane with a BC 48 trench cutter and an MC 64 with hydraulic grab DHG/V. Also employed: the BAUER Cutter Inclination System (CIS)^® for precise positioning of the diaphragm walls, as well as the Hydraulic Grab Inclination System (HGIS)^® for continuous monitoring and control of the hydraulic grab.

 

Digital tools for sustainability and quality

In order to manage the complexity of this large-scale project, the experienced team used digital tools for process optimization and lean management, key elements of the BAUER Construction Process. Thanks to detailed engineering, control and monitoring of all construction phases, it was possible to maintain optimal use of resources and the highest quality standards. “With our technology and decades of expertise, we are setting standards for geotechnical precision. By using our thoroughly tried-and-tested diaphragm wall equipment on the one hand, and advanced digital systems on the other, we are able to meet even the strictest accuracy requirements while ensuring optimally sustainable design,” explains Project Manager Stefan Neidhart.

Right from the start of diaphragm wall work on October 1, 2024, the crew from Bauer Spezialtiefbau showed full commitment. “Thanks to our dedicated team and state-of-the-art technologies, we have made a crucial contribution to this major project,” explains the project manager. The construction of the diaphragm walls was successfully completed in December 2024.

Further information:
BAUER AG
www.bauer.de

Schrobenhausen/Germany – A long-established tradition continues: For more than 35 years, BAUER Spezialtiefbau GmbH has been hosting the “Schrobenhausener Tage” lecture series. In April it was time again. This year’s motto: Focus Construction Site – stay tuned to Geotechnical Solutions. A total of roughly 300 guests attended from Germany and abroad, including participants from Japan who didn’t want to miss the event. They were all treated to a successful blend of fascinating presentations about spectacular construction projects in Germany, challenging international projects and the latest innovations in specialist foundation engineering. But that was far from all: another topic on the agenda was artificial intelligence.

Frank Haehnig, CEO of BAUER Spezialtiefbau GmbH, welcomed the guests and then handed over to Florian Bauer, Managing Director of BAUER Spezialtiefbau GmbH and moderator of the event. “You will see that the latest developments in specialist foundation engineering are very exciting. It’s not just our innovations and methods, but also the use of artificial intelligence that opens up countless opportunities and prospects for our sites,” remarked Florian Bauer.

From Germany…
The event kicked off with a lecture block addressing spectacular projects in Germany. Karsten Kegelbein, Site Manager for BAUER Spezialtiefbau GmbH in Hamburg, started off the series and presented a construction project in Helgoland. Surrounded by one-of-a-kind scenery there, Bauer implemented four different injection methods – far from a typical endeavor. In the next lecture, Susanne Nefzger, Head of Sales Bavaria for the South region, and Daniel Junger, Site Manager for BAUER Spezialtiefbau GmbH, presented a project for flood protection in the Bavarian town of Feldolling. A spectacular project with (almost) everything that specialist foundation engineering has to offer. Excavation pit monitoring during the CEFAM project in Cologne was addressed by Agnes Demharter, Site Manager at BAUER Spezialtiefbau GmbH, and Project Manager Andreas Hertenberger from the domestic business division. The morning’s lecture series was rounded off with an interesting guest presentation on “Monitoring of Geotechnic Works – the basis for sustainable and intelligent Geotechnics” by Prof. Dr. Christian Moormann from the Institute of Geotechnical Engineering at Stuttgart University.

During the lunch break, participants were able as usual to explore the innovations in specialist foundation engineering through an exhibition at the stands for the Technical Services, Design and Digitalization departments. Furthermore, in the exhibition area for the in-house exhibition of BAUER Maschinen GmbH starting several days later, an impressive array of equipment was presented along with ample opportunity to engage in dialog directly with experts in the field.

…to the entire world
Refreshed from their lunch break, the guests returned for the second thematic section of the event. This was entirely dedicated to international challenges. The first report was given by Shekhar Battacharjee, Senior Manager Business Development at BAUER Engineering India Private Limited, who discussed a subway project in the Indian metropolis of Chennai. Onur Askin, Technical Engineer at BAUER Spezialtiefbau GmbH, followed by presenting an impressive offshore project off the French Atlantic coast near Saint-Brieuc, as part of which Bauer installed 190 offshore piles for 62 wind turbine sites. Finally, Keith Ryan, Managing Director of BAUER International UAE, addressed the particular challenges involved in a construction project in Dubai for which the barrette foundations were implemented through an existing three-story basement level.

Digitalization and AI
The third and last thematic section of the event took a look at the future and digital challenges. Michael Jones, Managing Director of International Business Development at BAUER Technologies Limited, and Joachim Gaus, soil mixing expert in the Major Project Sales department, discussed the complex soil improvement measures that were carried out under water in 2023 working from a pontoon in Sweden. Marcus Daubner, Head of Digitalization, addressed the digital twin and presented specific practical examples. Richard Gutjahr, freelance journalist, moderator and blogger, concluded with interesting insights about the topic “Artificial intelligence – Hype or Change”.

This was followed by a final panel session with Christian Moormann, Richard Gutjahr, Marcus Daubner and Frank Haehnig in which the opportunities and prospects for artificial intelligence in specialist foundation engineering were thoroughly discussed. “We have a passion for progress and we are open to new ideas,” emphasized Florian Bauer. “In specialist foundation engineering, great opportunities await us through the use of AI, which we are tackling together.”

As usual, the traditional event concluded with lively discussions during a relaxed Bavarian dinner with regional specialties and authentic local music.

Further information:
BAUER AG
www.bauer.de

BAUER Spezialtiefbau GmbH is dedicated to more than just foundations. The company has set itself the goal of establishing the sustainable construction site as a standard and making a key contribution to a green future. Just last summer, the company was awarded the DGNB certificate for sustainable construction sites. Now another sustainability milestone has been achieved: On February 23, Florian Pronold, retired Parliamentary State Secretary and Managing Director of the Institut Bauen und Umwelt e.V., handed over six environmental product declarations for the Mixed-in- Place method (MIP) to representatives from Bauer Spezialtiefbau, including Managing Director (CEO) Frank Haehnig and Member of the Management Board Florian Bauer. “I am thrilled to present BAUER Spezialtiefbau GmbH with these environmental product declarations. Not only does this step underscore their commitment to transparent and sustainable specialist foundation engineering, it also sets whole new standards,” remarks Florian Pronold.

Basis for ecological assessment

Environmental product declarations, known as EPDs, deliver transparent environmental impact data verified by independent experts. This is a verifiable and transparent way to integrate the environmental compatibility of construction products into the assessment of a structure’s sustainability. Starting from the design phase, this extensive information is useful for designers, architects and owners. It allows them to make justified decisions for sustainable construction methods, for example by considering the carbon footprint.

Furthermore, this ensures that environmental compatibility requirements are fulfilled for a structure across its entire lifecycle. The EPDs serve as a basis for the ecological assessment of structures in accordance with DIN EN 15978. These declarations are coordinated at the international level and are based on ISO standard ISO 14025 as well as the European standard EN 15804.

Green milestone

“Our initiative with a total of six EPDs for our Mixed-in-Place method represents a significant milestone in the construction industry,” emphasizes Dr. Hursit Ibuk, Head of Construction Materials Technology and Product Sustainability at Bauer Spezialtiefbau. In the past, no environmental product declarations existed for construction products that were prepared directly on site using raw materials. The EPDs now encompass both the manufacturing process for the MIP material as well as the MIP method itself.

Efficiency meets sustainability

For more than 30 years, the Mixed-in-Place method developed by Bauer has proven successful for implementing retaining structures, foundation measures and flood protection. What makes this method unique: The construction material is produced on site in a sustainable and resource-efficient manner. “Thanks to many years of expertise, our employees’ know-how and continuous ongoing development of the drilling and mixing tools, the Mixed-in-Place method can now be implemented in nearly all soil types,” explains Dr. Hursit Ibuk. With a general type approval from the German Institute of Construction Technology, the MIP method can also be used for particularly challenging construction tasks.

Frank Haehnig, Managing Director (CEO) of Bauer Spezialtiefbau GmbH, proudly summarizes: “The environmental product declarations for our Mixed-in-Place method demonstrate very clearly that sustainability is not just a concept for us: it is our passion.”

Further information:
BAUER AG
www.bauer.de

A long-established tradition: For more than 30 years, BAUER Spezialtiefbau GmbH has been hosting the “Schrobenhausener Tage” event. This traditional event was held in early June this year under the slogan “B.sustainable: Sustainability in specialist foundation engineering.” What made this event unique: After a three-year break, it was finally possible to welcome the guests personally again in Schrobenhausen.

In the morning, guests were given an introductory talk from Arnulf Christa, CEO of BAUER Spezialtiefbau GmbH, in the Old Welding Shop: “Sustainability requires taking on responsibility. Accordingly, the development of resource-efficient, environmentally compatible innovations and technologies has for years now been a clear focus at BAUER Spezialtiefbau GmbH. We are proud to make an important contribution with our ideas.” The goal is to reduce the impact of specialist foundation engineering on humans and the environment, use raw materials more efficiently and manage projects in a sustainable and environmentally friendly manner. Looking back on the past two years, he reported in continuation: “Because of the pandemic, we had to deal with many challenges that required us to react flexibly. Nevertheless, our site teams around the world were fully committed – where possible – to successfully executing projects.”

In the exhibition area, participants were then able to visit various stations of the departments Technical Services, Design and Digitalization. The latest developments from Bauer were presented here – an excellent opportunity for guests to engage in dialogue with the experts. Last but not least, BAUER Maschinen GmbH also presented its innovative BAUER Cube System as well as its first electrified drilling rig.

The main series of lectures was then held in the afternoon as a hybrid event, with national guests participating on site and international guests participating via webinar. Hans- Joachim Bliss, former Managing Director of BAUER Spezialtiefbau GmbH, led the guests through the program with exciting and varied project presentations, live transmissions from sites in Germany and abroad as well as interactive discussions. For the international guests who participated virtually, the presentations were translated simultaneously.

Florian Bauer, Member of the Executive Board of BAUER AG and Managing Director of BAUER Spezialtiefbau GmbH, opened the series of presentations. He emphasized how important the topic of digitalization has become for specialist foundation engineering in his presentation “Digitalization at Bauer – Solutions for today‘s Construction Sites”. “The digital site is versatile. Apart from the use of digital tools such as data management software, databases or artificial intelligence, it is people, our employees, our teams, who are responsible for the success of our sites. Without them nothing would be possible,” he remarked.

This was followed by the first live transmission, from the Cairo Metro site in Egypt. Mohamed Sherif, Project Manager at Bauer Egypt, reported on the project, where top- down construction is currently being executed for the rapid transit system. Next came another live report from a site in Munich, Germany, given by Jee-Sun Rössler and Stefan Jäger, Sales Engineers for the south region of Bauer Spezialtiefbau. “For this project, the mixed-in-place method is being used. This involves using the existing soil as an aggregate. Removing the material becomes unnecessary, which can save time and money, but first and foremost CO₂.

After the live transmissions with Cairo and Munich there was a talk by Dr. Karsten Beckhaus, Head of the Technical Service Department at BAUER Spezialtiefbau GmbH, dedicated entirely to the topic of “B.sustainable: Sustainability in specialist foundation engineering.” He explained: “Our top sustainability goal is to be climate-neutral by 2050.” He further emphasized: “In this context, we are focusing on providing sustainable products for our customers.”

This year’s series of presentations concluded with a live transmission from Alaska: Bruno Luz, Project Manager at the US subsidiary BAUER Foundation Corp., reported on the extreme working conditions and logistical challenges involved with reinforcing the Moose Creek dam in the northern Arctic Circle. Between the presentations, the guests had the opportunity to ask questions through an online voting portal and engage directly in dialogue with the presenters.

The event was a resounding success, with approximately 150 participants on site and around 300 online viewers. This year, the traditional event concluded with lively discussions during a relaxed dinner.

Further information:
BAUER AG
www.bauer.de

Since the mid-1980s, hardly any other method has changed specialist foundation engineering as markedly as the development of diaphragm wall equipment. One milestone in this process was the introduction of the first Bauer trench cutter, which was used in 1984/85 to seal the Brombach Reservoir in Franconia (Figure 1). In just four months, this innovation conceived by Bauer engineers was designed, constructed and brought to the site – with resounding success: Despite some initial difficulties, the prototype was used to construct a wall 60 cm thick and 40 m deep. “This ‘technical adventure’ marked the start of a true success story, which has repeatedly gone beyond the limits of what was previously feasible and that is far from over,” says Leonhard Weixler, head of the Diaphragm Wall Equipment division at BAUER Maschinen GmbH. Since 1985, he has overseen the development of Bauer cutter technology in various roles.

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Special applications for Bauer cutters

In the following years, cutter technology at Bauer advanced in great strides – “always highly pragmatic, but also at times very bold and creative,” recalls Leonhard Weixler. The first cutters were sold to Japan and Turkey. In collaboration with a French partner, the maneuverable City-Cutter BC 15 was created for work in tight spaces and with working heights of just 5 m. New applications were later opened up with the Low Headroom machine that Bauer introduced on the market at the end of the 1990s. This was used to execute the encompassment of a subway station in Singapore underneath an existing airport building. Another machine of this type was used in China a few years later, in the Yeleh Dam project, to construct the sealing wall for a reservoir dam in a narrow tunnel.

Then in 2014, the CBC 40 Silent Cutter ushered in a new generation of equipment for projects in urban environments. The equipment performed impressively when it was used for a subway project in Singapore, particularly due to its low noise emissions, but also thanks to its compact dimensions, which were possible because of measures such as attaching the hydraulic power pack on the side. Next in summer 2019, an impressive depth record was set by a BAUER BC 50 cutter on an MC 128 duty-cycle crane: During a mining project in Canada, cutter excavation was for the first time carried out up to a depth of 251.4 m (Figure 2).

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Standard equipment in specialist foundation engineering

“In addition to all these special applications – some of them in difficult geological conditions – our cutters have also become established as reliable standard equipment in specialist foundation engineering, for example in the construction of diaphragm walls that can serve as retaining structures, for cut-off wall construction or as a foundation element,” emphasizes Leonhard Weixler. In addition, cutters also play an important role in soil mixing techniques such as Cutter Soil Mixing (CSM): Cutting wheels loosen the soil and mix it with a slurry to form a homogeneous soil-bentonite mortar. The method can be used to construct cut-off walls and retaining structures in various soil types, including hard soils.

Over the decades, Bauer has built and sold hundreds of cutter and CSM units. “The reliability of our equipment is largely also based on our decades of experience,” says Leonhard Weixler. “And our customers can also depend on that.” In recent years, however, the orientation for new developments and enhancements in Bauer cutter technology has been provided not only by customer requirements, but also by two major trends. “The topics of urbanization and sustainability are becoming increasingly important. They require proactive solutions, such as our first electrically powered cutter unit based on a BAUER MC 96 duty-cycle crane, which we presented in 2019 at the Bauma in Munich,” continues Leonhard Weixler.

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New applications

Finally, Bauer presented an innovation last year that opens up entirely new applications for the future of diaphragm wall construction: the electrically powered BAUER Cube System (Figure 3). This was developed precisely in the dimensions of a container. As a result, it can be easily used in tunnels with a diameter of just 3 x 3 m, a major advantage for cutter projects in densely populated large cities, for example. “The BAUER Cube System can be used precisely where the diaphragm wall needs to be constructed: underground,” summarizes Leonhard Weixler. This means that large-scale closures of urban areas could potentially be a thing of the past. The impact of construction sites on traffic, businesses, and residents (in particular) are minimized, even during daytime use. Another advantage is that the electric drive system considerably reduces the ecological disturbance of a cutter site. When it comes to logistics, the system’s compact dimensions are another major advantage. Instead of expensive heavy haulage, individual elements of the system can be easily transported to their place of deployment as conventional containers. “All in all, the BAUER Cube System sets new standards when it comes to sustainability in cutter technology,” concludes Leonhard Weixler.

Further information:
BAUER AG
www.bauer.de

One of the largest gold deposits in the world is located on the volcanic island of Niolam, the main island in the Lihir archipelago of Papua New Guinea. The mine was discovered in 1982 and the sought-after precious metal has been extracted in open-cast mines for nearly 25 years – now reaching a depth of up to roughly 300 m below sea level. For a planned expansion of the mine, an impermeable protective wall is required around the new extraction area because of its close vicinity to the Pacific Ocean.

According to the plans, a 1.8 km long cut-off wall will be constructed as part of a seepage barrier structure and will advance into the geothermally active foundation with temperatures of up to approximately 150 °C at a depth of 60 m. This seepage barrier has two primary functions: Sealing off the new extraction area or open pit against ocean and ground water ingress by the cut-off wall and protecting the mine from immediate inrush of water to the open pit in the event of an extreme earthquake, causing liquefaction of foundation sediments and failure of the cut-off wall.

Due to the unique location of the mine in a geothermally active Lihir Island, Papua New Guinea, BAUER Engineering PNG Ltd., a subsidiary of BAUER Spezialtiefbau GmbH, Schrobenhausen/Germany, was commissioned by the owner Lihir Gold Ltd., a member of the Newcrest Mining Group, in collaboration with Klohn Crippen Berger (KCB) – Newcrest’s seepage barrier cut-off wall design consultant – to execute two test cut-off wall elements with three diaphragm wall panels per element up to a depth of 55 m below the ground surface (Figure 1). “For the first time in the history of diaphragm wall construction, cut-off wall elements are being constructed in geothermally active foundation conditions with ground temperatures between 120 and 150 °C,” explains Gebhard Dausch, Project Manager at BAUER Engineering PNG Ltd. “Standard equipment combined with a unique slurry circulation system cooled by sea water was used for the work – without customization or special technical protection of the Bauer equipment against the unprecedented high temperatures within the foundation.”

The work included the construction of a total of six diaphragm wall panels in two cut-off wall elements. All six panels were constructed through approximately 30 to 35 m of loose respective blasted mine waste rock fill consisting of fine and course soil, gravels, cobbles and boulders up to 2 to 3 m in diameter, underlain by 15 to 20 m of marine sediments consisting of silt and sand as well as 5 to 10 m of highly altered – by high temperatures – of volcanic rock.

Five panels were keyed into the volcanic soil strata at a depth of 55 m below the ground surface and one panel reached a depth of 60 m. To determine the temperature and electrical resistance in the concrete, reinforcement cages with temperature sensors and multi-ring electrodes were lifted into the cut-off wall elements. A grouted body was also constructed around the diaphragm wall by means of pre-treatment grouting to prevent two slurry loss and trench collapse of the panels, and a plastic concrete specified by KCB with a high temperature resistance was used. A BAUER MC 128 duty-cycle crane with BC 30 cutter unit, an MC 96 duty-cycle crane with grab unit and a -BAUER BG 45 drilling rig with double-walled casing are being used for this work. During the diaphragm wall works, a special cooling unit developed for oil drilling is used along with the usual equipment. The heated bentonite flows through this mud cooler, thereby cooling back down to ambient temperature.

The work process speaks for itself: The hot soil respective rock cuttings are taken up into the cutter box then conveyed together with the bentonite suspension to the desanding plant, so that the bentonite suspension provides both cooling and insulation. Thanks to the addition of fresh bentonite in the trench, the slurry flowing down to the cutter cools the diaphragm wall panel. Even after reaching the final depth, the constructed diaphragm wall panel only heats up very slowly, making it possible to carry out installation of the reinforcement cage and the subsequent concreting works without significant risk for the employees.

Work by BAUER Engineering PNG Ltd. began in September 2020 and concluded in April 2021.

Further information:
BAUER AG
www.bauer.de

The Schwarze Pumpe industrial area in the city of Spremberg in Brandenburg covers a total of 720 ha and includes the former industrial site Spreewitz in the neighboring Free State of Saxony. Today, around 80 companies with some 4,250 employees are located in the area where lignite has been refined into briquettes, coke and city gas and converted into electricity in a power station since the mid-1950s. The gas combination plant Schwarze Pumpe, which was turned into the company Energiewerke Schwarze Pumpe AG in 1990, was one of the key pillars of the GDR’s energy industry. On the former grounds of the plant, various hazardous materials have however made their way into the soil over the decades, principally through the process of refining lignite. In addition to benzene, an amount of monoaromatic compounds (benzene, toluene, ethylbenzene, xylene) as well as polycyclic hydrocarbons (PAH) and hydrocarbons (HC) can be found. The soil contamination, which is extremely high in part, still acts as a source of groundwater pollution.

To remove this contamination, Lausitzer und Mitteldeutsche Bergbau-Verwaltungsgesellschaft mbH (LMBV), Senftenberg/Germany, recently commissioned BAUER Resources GmbH, Schrobenhausen/Germany, with its Bauer Umwelt business unit and the company Lobbe Industrieservice GmbH & Co KG, Duisburg/Germany, as JV partner to build and operate a vacuum treatment plant as well as replace or decontaminate the soil as necessary (Figure 1). All of the specialist foundation engineering and soil exchange measures will be executed by BAUER Resources GmbH and BAUER Spezialtiefbau GmbH. The work starts in November this year and should be completed by 2022.

As well as demolishing the existing superstructure on an area totaling around 25,000 m², Bauer will also produce six primary sheet pile walls with an overall length of 1,340 m and depth of up to 20 m as well as 147 sheet pile boxes (11.4 x 9.7 m) with a depth of up to 15 m. Every one of the six sections will be immured by a back-anchored primary sheet pile wall. Then, the entire section will be excavated 4.5 m below ground level. Following that, a working platform will be created from where the sheet pile boxes will be inserted. These will form the secondary sheet pile wall and will be secured with a reinforcement brace.

A telescopic excavator will be used to replace a total of over 281,500 t of contaminated soil down to 14 m below ground level. Because the contaminant benzene is an extremely volatile medium, the excavation will be carried out with continuous air extraction and purification. The contaminated groundwater, which to some extent is a mixture of oil and water, levels out in the sheet pile boxes and can be siphoned off during the excavation. The contaminated soil is taken to the treatment plant built and run by Lobbe and returned after it has been treated. As well as a BAUER BG 20 H drilling rig, an RG 22 and RG 16 from RTG Rammtechnik GmbH and a KR 806 anchor drilling rig from KLEMM Bohrtechnik GmbH will also be used among other equipment.

With over 25 years of experience, BAUER Resources GmbH’s Bauer Umwelt business unit is one of the leading specialists in site remediation, both in the domestic market and internationally. An expert in pollution reduction, the business unit offers a diverse range of services for all environmental issues within German-speaking Europe and neighboring countries. Organized by region, BAUER Resources GmbH concentrates on projects across the entire world together with its subsidiaries and has extensive skills in the fields of water treatment, automation, environmental remediation and waste management, drilling technologies as well as well-drilling and reed-bed treatment plants.

Further information/Weitere Informationen:
BAUER AG
www.bauer.de