Using underground spaces with regards to population expansion and the troubles of rail transportation is one of the basic infrastructure in developing countries. To this aim, life preservation of people and servicing them in important instances like accidental explosion conditions has a special importance. the dual application of tunnels and underground metro stations both as a sanctuary and as a means of transport; therefore, investigating the explosion impact in such constructions and an appropriate estimation about the imposed loads on them through the explosion is one of the most important aspects of passive defense.

In this study, the effects of tunnel cross-section geometry on the performance of the tunnel under explosion loading have been investigated using centrifuge modelling. Cross section of tunnels modeled in this study consists of rectangular, horseshoe and circular. According to the results, optimized cross-sections can be circular or horseshoe design is based on design targets.