ENGINEERING GEOLOGY PROPERTIES OF \u27KONJSKO\u27 TUNNEL

Istraživačkim radovima za potrebe projektiranja tunela «Konjsko» s dvije tunelske cijevi na autocesti Split-Zagreb, dobiveni su svi relevantni podaci o značajkama stijena i terena temeljem kojih su izrađeni prognozni inženjerskogeološki uzdužni profili. Zapadni portali tunela su locirani u naslagama zgnječenih i dijelom dinamički metamorfoziranih lapora eocenskog fliša, a istočni u naslagama senonskih vapnenaca. Kontakt flišnih lapora i vapnenaca je navlačan. Početkom iskopa tunela počelo je i redovito registriranje svih pojava i stanja stijenske mase nakon svakog miniranja, što je rezultiralo stvarnim uzdužnim inženjerskogeološkim profilima i poprečnim profilima čela. Odstupanja od prognoziranog stanja je bilo, a nastala su zbog nemogućnosti posve točnog određivanja nagiba navlačne plohe koja se nalazila plitko ispod nivelete tunela i pojave poprečnih rasjeda koji su raskinuli navlaku i uzdignuli lapore u dio tunelskog profila. Podaci prikupljeni prije i tijekom izvedbe tunela upotpunili su spoznaje o geološkoj građi šireg okoliša i fizičko-mehaničkim značajkama naslaga.Investigation works for the design of the Konjsko Tunnel with two pipes, part of the Split-Zagreb Motorway, provided relevant data on rock mass and soil properties for construction of the prognose engineering-geological longitudinal sections. West tunnel portals are situated in tectonically deformed and partly dynamically metamorphosed Eocene flysch marls, while east ones are located in Senonian limestones. There is an overthrust contact between flysch marls and limestones. With the beginning of the excavations, rock mass characteristics were regularly registered after each blasting and actual longitudinal engineering-geological cross-sections were constructed as well as cross-sections of the excavation face. There were some differences between prognosticated and registered sections since it was infeasible to accurately determine the dip of the overthrust plane that was at shallow depth below the tunnel grade line and also due to the occurrence of transversal faults that intersected the overthrust. Data collected before and during the tunnel construction complemented the knowledge on geological structure of the surroundings and physical-mechanical characteristics of strata

ENGINEERING GEOLOGY PROPERTIES OF 'KONJSKO' TUNNEL

Investigation works for the design of the Konjsko Tunnel with two pipes, part of the Split-Zagreb Motorway, provided relevant data on rock mass and soil properties for construction of the prognose engineering-geological longitudinal sections. West tunnel portals are situated in tectonically deformed and partly dynamically metamorphosed Eocene flysch marls, while east ones are located in Senonian limestones. There is an overthrust contact between flysch marls and limestones. With the beginning of the excavations, rock mass characteristics were regularly registered after each blasting and actual longitudinal engineering-geological cross-sections were constructed as well as cross-sections of the excavation face. There were some differences between prognosticated and registered sections since it was infeasible to accurately determine the dip of the overthrust plane that was at shallow depth below the tunnel grade line and also due to the occurrence of transversal faults that intersected the overthrust. Data collected before and during the tunnel construction complemented the knowledge on geological structure of the surroundings and physical-mechanical characteristics of strata (the paper is published in Croatian)