Static and dynamic analyses for the road tunnel’s on section Raec – Drenovo in Republic of Macedonia

Abstract

Even though tunnels are considered as one of the safest structures, worldwide studies show that huge damages can occur in tunnels and underground structures during and after earthquake event. Some of many other risks that can arise during tunnel exploitation are: contamination of ground water, air pollution and negative consequences in cases of eventual tunnel failure. This paper presents some of the analyses performed for the road tunnel on section Raec - Drenovo in Republic of Macedonia. Numerical model of the continuum as well as the primary and secondary lining of the tunnel, were made using the finite element method (FEM) which is implemented as a part of the software package PHASE2. Using the failure criteria of Hoek-Brown and the assumption that the surrounding rock material is elasto-plastic, static and dynamic numerical analyses were performed. Performing an engineering tunnel assessment is of huge importance for these types of structures, both from geotechnical and structural engineering point of view. The designing process for tunnels has to include the calculations considering their safety under different applied loads: temporary and permanent static loads and seismic loads, all in order to define optimal lining.