Geotechnika - Fakulta stavební - Vysoké učení technické v Brně

12 th International Scientific Conference, April 20-22, 2009 Brno, Czech Republic 73COOPERATING RINGS THEORY AT SETTING UP ADEFORMATION CHARACTERISTIC OF A TUNNELPRIMARY LINING BUILT FROM SHOTCRETE ANDSECTION BARSKarel VOJTASÍK, Josef ALDORF, Eva HRUBEŠOVÁ, Jana STAŇKOVÁ,Lukáš ĎURIŠThe paper refers the method setting up the stiffness of a shotcrete tunnel lining withsection bars. This method is drawn from the analysis of the rings cooperation. Suggestedmethod employs the analytical functions of complex variables to conceive the ringdeformations that observe a condition to be continuous on rings contours. This approachcan be an option to common practice of composite steel and concrete structure designsbetter matching the shotcrete lining structure taking into account its inherent traits.IntroductionThe shotcrete propped with steel elements constitutes a primary tunnel lining in most tunnels.The section of this lining seems to be such the composite steel and concrete section in buildingstructures and a lining design is done on building structures experience. In fact the both types ofsection differ in many respects. The most apparent contrariety consists in art the both types ofsection get in structure operation. At building structure the composite steel and concrete section isfabricated at first and then set into operation. The tunnel lining section is built up in steps (Fig.1)and from start step it’s in operation state. Lining parameters change in accordance with a liningbuilding step. The final shape of a primary tunnel lining isn’t known at many cases before and isdrawn on ground site circumstances.Fig. 1 Building steps of a primary shotcrete tunnel lining with section barsConcept of steel concrete designThe composit steel and concrete design transforms the concrete part of section on the steelequivalent reducing proportions of the concrete part of section so the true section is featured withsteel material and transformed section shape. Any change in the concrete part of a section invokesnew section shape. This concept may suit well when the materials are combined along with high ofVŠB-Technical University of Ostrava, Faculty of Civil Engineering, Dep. of Geotechnics and Underground EngineeringLudvíka Podéště 1875/17, 708 33 Ostrava PorubaCzech Republic