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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.

Copyright of Geomechanik und Tunnelbau is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Geomechanik und Tunnelbau is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

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. [ABSTRACT FROM AUTHOR]

A set of five fire tests involving battery electric vehicles and conventional cars was performed in a tunnel. This data article provides the dataset of some of the determined parameters: air temperature, air velocity and heat release rate. The air temperature was measured at several locations and at different heights, distributed in the cross section of the tunnel. The velocity of the incoming air was also measured. The third parameter, the heat release rate (HRR), was calculated based on the enthalpy flow before and after the fire location. This parameter is important for characterizing the size of a vehicle fire. The data provide a reference for the evaluation of BEV fires and could be taken as reference for further fire studies. They might be also of interest to research groups dealing with simulation applications, like three-dimensional CFD simulations., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2022 The Authors.)