Kombinovaná výstavba portálových úseků tunelů

Abstract

The aim of this bachelor thesis is to discuss the construction of a combined portal tunnel sections. The theoretical part gives an overview of the various ways of ensuring the stability of tunnel portals as well as a search of instabilities of tunnel portals with particulars examples from Slovakia, Czech Republic and Serbia. Further, we deal with the problems in combined construction of underground structures. Specifically, one of the kinds of cut-and-cover methods is the top-down method which uses the arched construction as a construction of a primary lining to secure the ceiling beneath which the excavation takes place. For completeness, there are given other methods of execution of underground construction. The practical part refers to a calculation of slope stability for two ways of securing portals in program GEO5. The first approach consists in excavation of construction pit to the tunnel invert. The second technique falls into an excavation of construction pit to the level of the arch construction which contributes to ensure the stability. The conclusion evaluates the comparison of two methods to secure the stability of the slope.