Rock fracture due to high-pressure fluid jetting and insert indentation was experimentally investigated. In the frame of this article, indentation designates the process of pressing a tungsten carbide insert (TCI) for roller cone bits displacement-controlled into the rock surface. Under atmospheric conditions, several crystalline and one sedimentary rock type were tested. Depending on the size, type and bonding of the mineral grains, distinct differences in fracture behaviour were observed. The influence of elevated ambient pressure regimes on the evolving cracks and fractures in the tested granite revealed that microcracking ceases with increasing ambient pressure, while the specific energy is also significantly affected. Under similar conditions, indentation experiments were performed on undamaged samples and on samples containing jetted kerfs. A distinct variation in the measured maximum force and removed volume indicated different underlying rock fracture mechanisms. By applying methods for crack visualization and three-dimensional rendering, it turned out that the dimensions of the kerf significantly affected the mechanism of fracture initiation and propagation as well as the extent of the associated fracture pattern. Furthermore, the common practice of characterizing the rock excavation process only via measurable quantities such as the specific energy, without considering the created fracture pattern, yields misleading results.

Deformation measurements of tunnel segments at a newly developed test rig Deformationsmessungen an Tübbingen mit einem neu entwickelten PrüfstandWith the use of tunnel boring machines under different geological and geotechnical conditions, the support with precast elements has been state of the art for decades. For the verification of the load-bearing and deformation behaviour of these high-strength reinforced concrete elements under exact known loading conditions, a test rig has been developed and implemented in a cooperation between experts of Austrian Federal Railways (ÖBB-Infrastruktur AG, SAE Fachbereich Bautechnik/Tunnelbau) and the Montanuniverität Leoben (Chair of Subsurface Engineering). The newly developed segment test rig allows biaxial tests on real segments. Due to the modular construction it is feasible to test segments with different geometries and dimensions. The obtained findings should be included in the optimization of these elements. Furthermore, the optimisation of the reinforcement design and replacement of steel bar reinforcement with fibre reinforcement is being investigated. With this test rig, an important step has been taken towards new technologies and materials in the field of segment linings. Currently, tests with distributed fibre optic sensing systems are carried out in cooperation with the Graz University of Technology (Institute of Engineering Geodesy and Measurement Systems -IGMS). A fibre optic sensing cable can be embedded in the segment during production and used for lifelong in-situ deformation measurements of the segment.

BIM modelling of infrastructure works is controlled by a global market consisting of few software suppliers and is contingent upon the functions provided by them. Customization options furnished by the software suppliers often enable enhancement of functions, which is essential for infrastructure BIM although not completely available. This enables improved interoperability of the software tools used in this area. IFC is most likely to become an established international format for data exchange with its constant but also intricate further development. However, in underground infrastructure construction, both international and national standards are used and the integration of the latter in IFC cannot be anticipated. Hence, the implementation of BIM has to apply national standards in the use cases of collaborative data exchange among the different disciplines in tunnelling. In this contribution, the use case of payment of excavation classes and its implementation in a BIM environment are addressed. It discusses the interoperable interlinkage of software tools commonly used in construction to generate consistent digital data transfer and it underscores the need for an interdisciplinary agreement to integrate national standards into adequate practice for the implementation of BIM.

Zusammenfassung Um notwendige Reinigungsarbeiten zur Aufrechterhaltung der Drainagewirkung von Drainagerohren in Tunneln zu minimieren, wurden im gegenständlichen Projekt Kunststoffe mit verschiedenen aktiven Wirkstoffen modifiziert, welche die Versinterungsneigung an den Rohroberflächen reduzieren sollen. Ausgehend von dieser praktischen Fragestellung wurden sieben verschiedene Rezepturen hinsichtlich ihres Potentials zur Verringerung der karbonatischen Versinterungen und zur industriellen Verarbeitbarkeit bewertet. Die hergestellten Compounds aus Matrix-Kunststoff, einem kommerziell verfügbaren Polyethylen-Rohr Typ und dem jeweiligen Wirkstoff sind zu Prüfkörpern verarbeitet und sowohl in Labor- als auch in Feldversuchen in realen Tunnelbauwerken ausgelagert worden. Anschließend fand die Beurteilung der Probekörper hinsichtlich der aufgewachsenen Versinterungen mittels chemischem Säureaufschluss, sowie optischen Analyseverfahren statt. Hinsichtlich der Verringerung der Versinterung zeigten das Polyethylen-Glykol Copolymer sowie das Compound mit Zeolith die besten Effekte.

Zusammenfassung: Ausgehend von der Problematik aufwändiger Instandhaltungsarbeiten für die Funktionstüchtigkeit von Drainagerohren in Tunnelbauwerken wurde das interdisziplinäre Forschungsprojekt "PolyDrain" initiiert. Im Rahmen des Forschungsprojekts werden diesbezüglich kritische Bauwerke in Österreich erhoben und vielversprechende Methoden zur Verringerung von zumeist karbonatischen Versinterungen in Drainagerohren untersucht. Durch gezielte Materialmodifikationen der Drainagerohre soll der Instandhaltungsaufwand zukünftiger oder zu sanierender Tunnelbauwerke reduziert werden, indem Reinigungsintervalle gestreckt und/oder Reinigungen rascher durchgeführt werden können. Der gewählte Ansatz umfasst die maßgeschneiderte Modifizierung von Kunststoff-Drainagerohrmaterialien. Dadurch ist es möglich, mechanisch widerstandsfähigere Rohre zu erzeugen und/oder das Versinterungsverhalten im Drainagerohr, inklusive der Drainageschlitze, zu reduzieren. Bevor eine Umsetzung im großtechnischen Maßstab möglich ist, ist es allerdings wichtig, nicht nur die kurzzeitige Wirksamkeit-im Projekt auch im Labor-zu untersuchen.