NON-SHALLOW SPHERICAL SHELLS


Study of the propagation of combustion products on the models of road tunnels  

for various fire scenarios 
 

Omar Lanchava 

 

G. Tsulukidze Mining Institute, Tbilisi, Mindeli Street, 7 

lanchava@mining.org.ge 

 

The idea of the research is based on increasing the aerodynamic resistance of the tunnel with the 

help of a transformable system (TS), which will prevent the spread of combustion products without 

interfering with people’s movement, and will stimulate the differentiation of fresh and polluted air flows. 

As a result, in the critical sections of the tunnel, fresh air maintains longer, giving more time for evacuation. 

The noted event is characterized by a sharply limited time interval, which depends on many components, 

including the power of the fire and the scenario of its development, the type of toxic compounds emitted 

and the nature of their propagation, the geometry of the tunnel and the ventilation system. At the beginning 

of the 21th century, in newly built tunnels began to build fireproof barriers that can divide the tunnel into 

short sections. These barriers prevent the spread of fire, smoke and other combustion products along the 

length of the tunnels. But this method is not the final decision, due to the fact that there is no place for its 

implementation in the "old" tunnels without sacrificing the underground space of the tunnel and its traffic 

capacity. It should be emphasized that the use of the method of dividing the tunnel into short sections is 

not envisaged in the design solutions in the tunnels being operated and under construction in Georgia. 

Particularly in Georgia it is planned to build more than 50 road tunnels in the next 3-5 years. Inspecting 

the design decisions of these tunnels revealed that the only significant risk factor for them is the fire when 

safety measures do not provide for the operational separation of them. Based on this the issue of the 

development of this project is directly vital and very relevant for the conditions in Georgia. There are 

required theoretical analysis the correlation of critical speed and backlayering length with fire 

characteristics without the influence of the transformable system and taking into account its influence. 

Accordingly, the influence of artificial barriers on the dynamics of ventilation flows, the formation and 

development of bifurcation flows, the propagation of damaging factors and other important parameters 

should be determined, which should be applicable to the geometry, topology and location of a particular 

tunnel. 

 

Acknowledgement. This work was supported by Shota Rustaveli National Science Foundation (SRNSF) 

[Grant number AR-19-1936, Project title “Development and testing of transformable system to save life 

in road tunnel in case of fire”]. 

 

References 

1. Li Y.Z., Ingason H. Discussions on critical velocity and critical Froude number for smoke control in 

tunnels with longitudinal ventilation. Fire Safety Journal, Vol. 99, 2018. 

2. Lanchava O., Medzmariashvili E., Ilias N., Khitalishvili G., Lebanidze Z. Prospects of usage of 

transformable systems for extinguishing fire in tunnels. International Scientific Conference “Advanced 

Lightweight Structures and Reflector Antennas”, Tbilisi, 2009. 

3. Lanchava O., Ilias N., Nozadze G. Some problems for assessment of fire in road tunnels. Quality Access 

to Success, Vol. 18, S1, 2017. 

 

mailto:lanchava@mining.org.ge