Barriers provide an ever-increasing role in traffic management. The well-established Osnabrück company RAWIE is one of the leading providers of innovative security solutions. RAWIE offers a wide range...
Sprayed concrete construction in double-shell lining is a CO2-intensive construction method for tunnel structures. This article explains the ecological impact of concrete in underground construction and provides options for using this material responsibly and in a climate-friendly way – particularly in terms of planning and concrete technology.
The research facilities of the European Organisation for Nuclear Research, CERN, currently extend at the foot of Lake Geneva on Swiss and French territory. With a length of 27 km, CERN operates the...
The first part of this article was published in the 3/2021 issue of tunnel [15]. There, the authors present the AJRM method. The rock mechanical model is explained. With the aid of case studies, the advantages of a realistic simulation of the behavior of jointed rock as well as of the interaction of rock mass and structure are illustrated. As announced, part 2 of the article deals with the rock hydraulic model and related case studies as well as with the determination of the required parameters. Thus, an overall method for a safe and economic design of structures as well as for groundwater modeling in jointed rock is available.
The decision has been made: Thanks to the far advanced vaccination campaign against the coronavirus, the „family reunion of the tunnel industry“, the STUVA conference with accompanying trade exhibition STUVA-Expo, is to take place as a face-to-face event in the familiar manner from 24 to 26 November 2021 at Messe Karlsruhe.
On the closing day of the 9th International Symposium on Tunnel Safety and Security (ISTSS) on 7 May 2021, Prof. Dr.-Ing. Alfred Haack received the ISTSS‘s prestigious Achievement Award for his...
Mechanized tunneling in difficult geological conditions, such as soils with significant swelling potential due to water uptake by the clay minerals, depends not only on the calibration of the tunnel boring machine to the ground characteristics, but also on the ability of the tunnel lining to tolerate localized swelling pressures. In order to avoid the risk of damage to the tunnel lining, additional radial layers such as a compressible tunnel lining segment and a compressible annular gap grout can be included. However, the deformability of a tunnel support after reaching a certain yielding load affects the distribution of the stresses and deformations around the tunnel and as a consequence determines the magnitude and buildup of the swelling pressure. Thus, the goal is to develop a lining system i.e. material design and structural design that ensures an optimal soil-structure interaction through a synergy of computational and experimental techniques.
In the past, tunnel fires have often led to major structural damage, and the tunnel had to be closed for a long time to repair the damage. Not only the repair costs, but also the unavailability led to...
Cement-based or chemical grouting materials are the foremost choice to seal water-bearing areas in subsoil or rock efficiently. Anti-wash out resistant cement-based grout mixes and water-reactive grouting materials based on polyurethane are the preferred material for pre-excavation grouting. However, adequate equipment and material technology nowadays enable controlled processing of combined cement-polyurethane grout mixes, which withholds the benefits of both materials types.
