Stability analyses of tunnels excavated in weak rock masses using empirical and numerical methods [Zayi{dotless}f kaya kütlelerinde açi{dotless}lan tünellerde ampirik ve nümerik yöntemlerle durayli{dotless}li{dotless}k analizi]

In terms of geological engineering,tunnel design in weak rock masses presents some challenges. a small misinterpretation in the design stages can lead to costly and time-consuming problems at the construction phases. to avoid serious problems of these kinds,tunnels excavated in weak rock masses should be projected with the most suitable and economical excavation method in design stage. in this study,stability of the thin-bedded marls belong to paleocene aged şenkaya si{dotless}rti{dotless} formation,outcropped on the route of cankurtaran (hopa-artvin) tunnel,was investigated using empirical and numerical methods. firstly,the properties of the discontinuities in the marls and geomechanical parameters of intact rock material were determined based on the description criteria of isrm (1981). in the next stage,marls were classified by using the rmr,q and gsi systems and rock mass properties were determined. in the final stage,the stability of the tunnel,planned to be excavated in the marls,was investigated by using the criterion of singh et al. (1992),goel et al. (1995),bhasin and grimstad (1996) and finite element method (fem). as a result of the analyses,it was concluded that the factor of safety value varies between 0.08 and 1.43 and there may be a risk of instability problem in the tunnel.