Abstract
Tunnel Safety and Risk Analysis within the Scope of Dangerous Goods Transport on Roads
Tunnels are specific transport structures having great social and economic importance in road transport infrastructure due to their ability to overcome geographical limitations. Safety is an important issue in these structures since they provide uninterrupted service. Past accidents have led to the need to question the safety of road tunnels. Approaches for providing international-level tunnel safety have been developed and are intended to be standardized practices. In the study, it was aimed to evaluate the safety of road tunnels in terms of the riskiest, dangerous goods being transported. First, the current situation in the world and international legislation were evaluated and country practices were examined. Afterwards, due diligence was made for our country, possible problems were summarized, and solutions and suggestions were presented. Besides, a case study was carried out through the ALOHA (Areal Locations of Hazardous Atmospheres) Software for the transportation of dangerous goods in the tunnel. In practice, the effects of fire, explosion and toxic dispersion were modelled on the scenarios of (i) a leaking tank where a chemical is not burning as it escapes into the atmosphere, (ii) a leaking tank, where a chemical is burning like a jet fire and (iii) BLEVE (Boiling Liquid Expanding Vapor Explosion), the tank explodes and the chemical burns in a fireball. The largest effect distances of BLEVE for red, orange and yellow threat zones were 10kW / sq m (potentially lethal within 60 sec) =355m, 5.0kW / sq m (2nd-degree burns within 60 sec) =502m and 2kW / sq m (pain within 60 sec) =781m, respectively. It has been shown that ALOHA, a free software, can be used practically to manage road hazards. The passage of hazardous materials through tunnels can be modelled on scenarios in advance and an appropriate road route can be determined. Thus, wastes of time and material expenses in dangerous goods transportation can be eliminated.
Keywords
Road transport, tunnel safety, dangerous goods transportation, risk analysis, ALOHA Software.
