Tunnel Number 02
- Parametric Model
Design Challenge:
The design and implementation of emergency exits in railway tunnels present a critical safety challenge. Ensuring that passengers can evacuate a train safely within a prescribed timeframe is vital, particularly in tunnels spanning several kilometers. The complexity of this task increases with variations in tunnel geometry, like one or two railways (increase in passenger), or length of the tunnel. This assignment explores how Dynamo Sandbox can be utilized to model and analyze emergency exit placements, ensuring compliance with evacuation time constraints and balancing safety with cost considerations.
Tackling the problem:
Railroad tunnels are inherently dangerous environments in the event of emergencies such as fires or derailments. The limited entry and exit options exacerbate the challenges of evacuation. Regulatory standards often dictate that passengers must be able to evacuate to a safe zone as fast as possible. In Germany, there is no legally defined maximum evacuation time for railway tunnels. However, 20 minutes is a commonly accepted assumption for planning purposes, ensuring sufficient time for passengers to reach a safe zone [1]. This is usually based on human walking speed and safety multipliers for crowd dynamics. Key parameters to consider include the average pedestrian speed, which is approximately 5 km/h, and a crowd congestion multiplier of 0.25 [2], reflecting reduced movement efficiency in crowded conditions. Tunnel lengths are often several kilometers, making multiple emergency exits a necessity. However, the inclusion of additional emergency exits significantly increases construction and maintenance costs, representing a critical cost factor in tunnel planning.
Implementation Idea:
The idea was to create a main tunnel that could be adjusted in position and radius using number sliders. Based on the tunnel diameter, the criteria for determining whether it would be a single-track or double-track tunnel were to be defined. Subsequently, rescue pathways in the form of parallel rescue tunnels were to be generated. These rescue tunnels needed to maintain a precise distance from the main tunnel at all times. To achieve this, a normal vector for each point of the main tunnel was to be calculated in the direction of the next points, followed by creating a perpendicular vector to this normal vector. Finally, the connections between the tunnels were to be established, with their distances adjustable using additional sliders. As a result, the maximum distances to the respective emergency exits could be calculated and an evacuation time could be calculated using the average speed. The costs for the escape routes and tunnels would also be supplemented with simple calculations.
Conclusi0n
It is crucial to underline that the primary focus of this project is on safety engineering, particularly the development of safety concepts and strategies. The aesthetic aspects of the model, as well as any visual adjustments to the tunnel’s representation, are secondary and should be disregarded. The key objective is to design and conceptualize an effective evacuation plan, incorporating considerations of feasibility and cost.
The final output is a fully customizable, parametric tunnel system that offers significant flexibility for adjustments based on specific requirements. The model is designed to automatically generate evacuation tunnels running parallel to the main tunnel, ensuring a consistent and precise distance between them. These evacuation tunnels are seamlessly integrated with emergency exits to provide a comprehensive safety solution.
References:
- Erörterungsverhandlung zum PFA 1.3 Bahnprojekt Stuttgart–Ulm Brand- und Katastrophenschutz. (o. D.). https://www.bahnprojekt-stuttgart-ulm.de/fileadmin/pdfs/10- S21_NEUORDNUNG_BAHNKNOTEN_STUTTGART/ PfA_1_3/2014/20140926_Praesentation_Brandschutz_PFA13_EOeT.pdf.
- Bewegungsverhalten von Fußgängern im Straßenverkehr – Teil 1 -. (o. D.). In Verkehrsunfallforschung An der TU Dresden GmbH (VUFO). Verband der Automobilindustrie.