Geomechanik und Tunnelbau最新文献

200 m full of power: Herrenknecht's double-shield TBM (diameter 10,650 mm) for driving the western main tube of the Brenner Base Tunnel (BBT) on the Italian side. Two BBT milestones were celebrated in May, more on page 170. (Photo: Herrenknecht AG)

The maintenance and safety assessment of tunnels are fundamental to infrastructure management, requiring a structured and standardized approach to ensure resilience and regulatory compliance. In Italy, the post-war expansion of the transport network led to the construction of a huge number of tunnels, many of which are now approaching the end of their design life after more than 70 years of service. With over 9000 tunnels spanning approximately 2600 km across the national territory, managing this extensive asset presents a significant challenge, particularly within the framework of a complex and aging road network. To address these challenges, Italian tunnel maintenance regulations have evolved over time, culminating in the 2022 Italian Guidelines for the Risk Classification, Safety Evaluation, and Monitoring of Existing Tunnels. Developed by the Italian Superior Council of Public Works, these guidelines provide a unified methodology to assess risk, ensure safety, and plan maintenance operations at a national scale. They are now a mandatory reference for roadway existing tunnels across the country. This article analyses the structure and implementation of these guidelines, tracing their development from earlier regulatory frameworks, including Circolare 6736/61A1/67and the MIT Manuale di Ispezione. Furthermore, it explores the influence of international best practices, particularly the adoption of key principles from the French regulatory framework, such as the defect cataloguing system. A comparative analysis highlights both the similarities and distinctions between the Italian and French approaches, emphasizing common methodologies in risk assessment and inspection protocols. By examining the integration of these principles within the Italian regulatory framework, this study provides valuable insights into the evolution of tunnel maintenance strategies. The findings serve as a reference for policymakers, engineers, and researchers involved in infrastructure monitoring and safety management, offering a comprehensive overview of Italy's approach to tunnel maintenance in the view of increasing structural and operational challenges.

The M_w 7.8 Gorkha (Nepal) earthquake of 25 April 2015 resulted from fault rupture along the Main Himalayan Frontal Thrust. It resulted in approximately 8800 deaths, tens of thousands of injuries, and hundreds of thousands of destroyed buildings. The earthquake also triggered extensive landsliding. This research summarizes the findings of an inventory of more than 13,000 seismically induced landslides that occurred in the districts Rasuwa, Nuwakot, Dhading, and Sindhupalchok, located north of Kathmandu. The landslide inventory was developed by comparing pre- and postearthquake digital satellite imagery (Google Earth Pro) and targeted ground-truthing during postearthquake field reconnaissance studies. Identified landslides were then imported to GIS to ascertain the impact of contributing factors such as slope steepness, elevation, and aspect, along with soil type and peak ground acceleration.

Bestandsaufnahme der Hangrutschungen in Folge des 2015 Gorkha (Nepal) Erdbebens

Das Mw 7,8 Gorkha (Nepal) Erdbeben vom 25. April 2015 wurde durch einen Bruch entlang der Main Himalayan Frontal Thrust ausgelöst. Es führte zu etwa 8800 Todesopfern, zehntausend Verletzten und hunderttausend zerstörten Gebäuden. Außerdem führte es zu einer übermäßigen Anzahl von Hangrutschungen. Diese Studie fasst die Ergebnisse einer Bestandsaufnahme von mehr als 13.000 Erdbeben bedingten Hangruschtungen zusammen, die in den nördlich von Kathmandu gelegenen Bezirken Rasuwa, Nuwakot, Dhading und Sindhupalchok aufgetreten sind. Das Erdrutschinventar wurde durch den Vergleich digitaler Satellitenbilder (Google Earth Pro) aus der Zeit vor und nach dem Erdbeben sowie durch gezielte Bodenverifikation im Rahmen von Feldstudien erstellt. Die identifizierten Hangrutschungen wurden anschließend in ein GIS importiert, um die Faktoren zu ermitteln, die zur Entstehung der Hangrutschungen beigetragen haben, wie z. B. Hangneigung, Höhe und Ausrichtung sowie Bodentyp und Spitzenbodenbeschleunigung.

Pletzachkogel is a mountain North of the Tyrolean Inn valley in a prominent position above the village of Kramsach. Three major rock avalanches have occurred since the last glaciation and ongoing rockfall from the head scarp area presently affects local infrastructure. This study presents geological and geomechanical investigations of Pletzachkogel that were performed using conventional and uncrewed aerial vehicle (UAV) mapping techniques and focused on understanding the different landslide processes. The investigation indicates that the gravitational instability is related to a stratigraphic sequence of “Hard on Soft” rock units: Hauptdolomit and Plattenkalk beds (hard) – Kössen Formation (soft) – Oberrhätkalk and Lower Jurassic Breccia units (hard). “Hard on Soft” slope deformation has been described for similar stratigraphic conditions and involves the overlying hard rock mass breaking apart over a soft underlying unit. This leads to distinct geomorphological features like buttresses. In addition to the “Hard on Soft” stratigraphy, synsedimentary deformation during deposition, polyphase, heteroaxial, tectonic deformation during Alpine orogenesis, and glacial loading and unloading during the last ice age exacerbated landslide processes. This study describes the “Hard on Soft” geomechanics of Pletzachkogel and also demonstrates the value of UAV-based structural mapping, particularly for acquiring and quantifying structural rock mass data in inaccessible areas.