tunnels tunneling works 79 underground structures 51 drfting 27 geoengineering 26 underground (transport) 25 transport constructions 24 more ... history 16 civil engineering 16 railway structures 16 simulation and modelling 14 building designing 13 silniční stavby 12 tunnelling shields 10 foundation engineering 9 zemní práce 9 geological survey 8 roads 8 concretes 7 urban underground transport 7 fire protection 7 machines for underground and tunnelling works 7 iron-concrete constructions 7 stavební inženýrství 6 building constructions 6 real estate development 6 railway tunnels 6 concrete constructions 5 waterproof insulations 5 undermining 5 less ...