Kern Tunneltechnik

The growing complexity of concrete mixes and the need to maintain their properties during transport and placement, has made traditional systems not sufficiently suitable. With respect to the secondary Lining works of Tideway West KERN Tunneltechnik and BMB JV carried out a deep analysis of the lessons learnt from previous projects and decided to design and deliver a new innovative device to reduce the potential risks of compromising high spec concrete during transport. A homogeneous consistency and the avoidance of fibres segregation are in the focus of this development. A containerized system combined with continuous agitating was developed in order to reduce a potential quality drop due multi-handling of the concrete. The mixer is designed with a volume capacity of 6m3 to comply with the common batching plants production rates. No.3 vertical shafts with paddles and spirals provide enough mixing capability to keep the mix stable. Furthermore, the system is provided with an hydraulic motor able to control the RPM of the paddles connected to the vertical shafts. A mock-up was erected at KERN’s factory and several trials have been carried out using different type of concrete. During this process, the device has been improved with the addition of technical details. Finally, the mixing capability could be demonstrated. At the discharge of the concrete, fibres and aggregates were mixed properly with and unloading time of less than 5 minutes. The concrete placement is another key element during the concrete works. In the past several semi-automated concrete distribution systems and concrete ports have been developed. All these systems still require a high degree of manual handling. Steel and plastic fibres push the existing systems to their limits. Blockages and trapped fibres are causing delays and end up in additional manual handling. KERN’s brand new and innovative K-ONE concrete valve eliminated the above issues and allows and highly automated process. Designed to be installed directly on the formwork skin, the K-ONE combines the flexibility and efficiency of having a complete integrated system. Concrete pouring is rapid, safe and clean. The concrete lines stay in place and will not be cracked after the pour is finished. A built-in plunge pushes the remaining concrete through the formwork and creates a smooth surface. The concrete placement device can be operated thorough remote control or PLC. The automated features result is a drastic labour requirement reduction. The K-ONE has been deeply tested in combination with the mixer. The achievement allows to control and manage steel or plastic fibres with no issues. This results in cost savings, health & safety and quality. Furthermore, the two systems have a digital interface controlled through the use of a PLC. Live feedback and Data log will provide to the construction companies a full package of information which can be shared to improve efficiency. KERN Tunneltechnik believes that this Innovation in Design & Delivery will be part of the future standard of the Tunnelling construction activities.

This award seeks to showcase a tunnelling concept or proposal that would see underground space used in a creative way to address a specific challenge. The challenge being addressed could be urban densification, energy production and storage, inter or intra-city transport, water supply and distribution or any other infrastructure challenge. The concept or proposal does not need to have secured financial or political support but it should be possible to offer evidence of how the opinion and support of key stakeholders has been sought. The concept or proposal could be entirely unique, a bespoke version of an existing concept or the first use of an previously used concept in a new territory.

From designing end-to-end project solutions to pioneering new technologies and ways of working, we generate the knowledge, the ingenuity and the drive to meet so many of today’s most pressing challenges – population growth, transportation, and climate change.