tunnels tunneling works 90 underground structures 51 drfting 35 underground (transport) 29 transport constructions 28 geoengineering 26 more ... history 17 civil engineering 16 railway structures 16 simulation and modelling 15 building designing 14 concreting works 13 silniční stavby 12 tunnelling shields 11 iron-concrete constructions 10 foundation engineering 9 zemní práce 9 concretes 8 geological survey 8 roads 8 concrete constructions 7 urban underground transport 7 fire protection 7 machines for underground and tunnelling works 7 real estate development 7 concrete lining 6 building construction reliability 6 stavební inženýrství 6 building constructions 6 less ...