Auxiliary measures applied in the tunnel construction of the Jonica
Transcription
Auxiliary measures applied in the tunnel construction of the Jonica
Salvatore Lieto (ASTALDI S.p.A.) Paolo Perazzelli (ETH Zurich) Auxiliary measures applied in the tunnel construction of the Jonica motorway Kolloquium Bauhilfsmassnahmen im Tunnelbau ETH Zürich Outline Project overview Tunnel construction problems and design changes Conclusions Project overview Old motorway Taranto Jonica motorway (490 km) Reggio Calabria Project overview New motorway Taranto Completed Sections Launched Assigned and not launched In design Reggio Calabria Project overview Taranto ASTALDI S.p.A. as General Contractor Section 3 (Sibari - Roseto Capo Spulico) Completed Sections Launched Assigned and not launched In design Section 2 (Squillace - Simeri Crichi) Section 1 (Gerace - Marina di Gioiosa Jonica ) Reggio Calabria Project overview “Strada extraurbana principale – Cat. B (D.M. 5 novembre 2001) ” Two-lane dual carriageway (lane width 3.75 m) Velocity: 70 - 120 km/h Total length 11.3 km Project overview Costs of the project = 354 Ml € GERACE TRIGONI Two-tube tunnels n° 5; l = 2.6 km TIMPA PERGOLA Two-tube cut-and-cover tunnels n°7; l = 1.1 km LIMBIA Viaducts n° 7; l = 2.5 km Project overview ground surface water table H = 4.5 m – 75 m I = 30-35 m 9.75 m 1.75 9.4 m 3.75 3.75 0.5 11.9 m B total length of the tunnels (L = 5.2 km) 35% H>2B 35% 2B>H>B 30% H<B Upper Pliocene Lower Pleistocene Holocene Project overview Qt Quaternary deposits (superficial deposits) Qt Pl Pl Monte Narbone formation (gravelly sand) Ap Trubi formation (silty clay, clayey silt) Sp Trubi formation Pl 25% (clayey sandy silt) z [m] total length of the tunnels (L = 5.2 km) 5% 20% Pl Sp 75% Ap Outline Project overview Tunnel construction problems and design changes Conclusions Ap Tunnel construction problems and design changes Limbia Tunnel Carr. Nord L = 385 m 120 m Pl (gravelly sand) 80 40 0 considered section Tunnel construction problems and design changes Pl : Monte Narbone formation (gravelly sand) 0% 0% Granulometry granulometry 50% 100% 50% 100% Gravel Sand cohesion c’ = 0 friction angle I’ = 30°– 45° 0 0 90 Dr [%]D =100% =100 Limbia R 100 NSPT V’v [kPa] relative density Dr = 40 - 80% DR=80% 80 200 80 AS36 70 N SPT ʍ'v (kPa) 200 80 60 60 300 60 40 50 45 40 400 400 40 40 Limbia 500 30 AS36 Limbia 1 600 35 20 30 20 600 0 0 10 20 20 30 40 40 50 60 60 70 80 80 NSPT NSPT 25 10 0 0 0,0 0 0,5 1,0 1,5 2,0 2 5,0 ) 250 V’ [kPa]ʍ (kg/cm 500 v 2,5 3,0 3,5 4,0 4,5 Tunnel construction problems and design changes 24 m drainage A B C jet grouting columns reinforced with steel pipes 10.3 m jet grouting columns reinforced with fiberglass bolts 1.25 9 A B C Installation every 9 m of advance 14 18 length of round= 0.75 m 0.6 m A-A B-B (after exc.) drainage 0.72 0.67 C-C 0.8 m 1.5 m 9.7 0.4 m shotcrete and steel ribs 13.8 15.4 Tunnel construction problems and design changes In situ jet grouting tests Mono fluid system Column [-] Design diameter [m] Column [-] 1 3 5 7 2 [MPa] 40 40 35 35 [-] 2 2 2 2 [mm] 2.4 2.4 2.4 [-] 1 1 1 [l/min] 57 57 [l/m] 380 [mm/s] 5 Grout pressure Number of nozzles Nozzle Diameter W-C ratio by weight Grout flow rate par nozzle Injected grout volume per unit length Average lifting speed of the monitor Observed diameter [m] 1 3 5 7 2 4 6 8 4 6 8 40 40 35 35 2 2 2 2 2.4 2.4 2.4 2.4 2.4 1 1 1 1 1 53 53 143 119 155 133 333 442 398 108 90 117 100 5.7 4 4.5 13.3 16.0 11.5 13.3 0.85 - 0.95 0.44 - 0.5 0.8 0.75 - 0.85 0.4 0.39 - 0.48 0.62 - 0.71 0.55 - 0.65 Tunnel construction problems and design changes 10.3 m 9m 5m 10.3 m 9m Tunnel construction problems and design changes 10.3 m 9m 5m 10.3 m 9m advance rate [m/day] Tunnel construction problems and design changes 2 1.5 1 0.5 original design 0 0 5'000 10'000 15'000 20'000 25'000 costs [€/m] Tunnel construction problems and design changes Limbia Tunnel Carr. Nord L = 385 m 120 m Pl (gravelly sand) 80 40 0 new design advance rate = 0.25 m/day Tunnel construction problems and design changes A-A jet grouting columns A 15-35 m 4 drainage 10 m 1.25 12 m A 1.2 shotcrete and steel ribs Tunnel construction problems and design changes A-A A B jet grouting columns 15-35 m 4 drainage 10 m C C 1.25 A A B B 12 m 1.2 C-C B-B 1m 0.9 m 14.3 1.2 m A B shotcrete and steel ribs Tunnel construction problems and design changes In situ jet grouting tests Mono fluid system Grout pressure 40 MPa Number of nozzles 2 Nozzle Diameter 4 mm W-C ratio by weight 1 Grout flow rate par nozzle 160 l/min Injected grout volume per unit length 733 l/m 800 l/m 933 l/m Average lifting speed of the monitor 7.3 mm/s 6.7 mm/s 5.7 mm/s 0.9 0.9 0.9 0.5 m 4.5 m Design values Dt =1.2 m Observed Dm =1.04 m 1.2 Lt = 2.1 m Lm =2.03 m 1.2 Lt = 2.1 m Dt =1.2 m Dm =1.06 m Lm =2.07 m Dt =1.2 m 1.2 Lt = 2.1 m Dm =1.25 m Lm =2.15 m Tunnel construction problems and design changes In situ jet grouting tests Mono fluid system Design values Grout pressure 40 MPa Number of nozzles 2 Nozzle Diameter 4 mm W-C ratio by weight 1 Grout flow rate par nozzle 160 l/min Injected grout volume per unit length 969 l/m Average lifting speed of the monitor 5.5 mm/s Injected grout volume per unit length 733 l/m 800 l/m 933 l/m Average lifting speed of the monitor 7.3 mm/s 6.7 mm/s 5.7 mm/s 0.9 0.9 0.9 0.5 m 4.5 m Design values Dt =1.2 m Observed Dm =1.04 m 1.2 Lt = 2.1 m Lm =2.03 m Dt =1.2 m Dm =1.06 m 1.2 Lt = 2.1 m Lm =2.07 m Dt =1.2 m 1.2 Lt = 2.1 m Dm =1.25 m Lm =2.15 m Tunnel construction problems and design changes 12 m 12 m shotcrete and steel ribs 12 m 12 m advance rate [m/day] Tunnel construction problems and design changes 2 1.5 1 new design 0.5 original design 0 0 5'000 10'000 15'000 20'000 25'000 costs [€/m] Tunnel construction problems and design changes Trigoni Tunnel Carr. Sud L = 880 m Ap (silty clay) 120 m 80 40 0 considered section Tunnel construction problems and design changes Ap Trubi formation (silty clay, clayey silt) 0% granulometry 50% 100% Sand Silt Clay 90 60 plasticity index (%) c’ [kPa] 60 30 50 CH 40 0 30 CL 20 10 CL-ML 0 0 20 OL ML OH MH 20 40 60 80 limit liquid (%) 30 I’ [°] 100 40 Tunnel construction problems and design changes B A grouted steel forepolings 9.8 m fiberglass bolts 12 1.25 12 A 16 concrete invert length of round = 0.75 m A-A installation every 12 m of advance B 18 m 60-110 fiberglass bolts (density 0.5 - 0.9 bolts/m2) B-B (after exc.) 48 steel forepolings (spacing 0.4 m) shotcrete and steel ribs Tunnel construction problems and design changes surface fractures induced by the excavation excavation faces 0.2 m uv uv uh1+uh2 uh1 uh2 re-profiling of the tunnel section in order to guarantee the minimum clearance profile design threshold 0 monitoring stations in a distance of 24 m from the tunnel face advance rate [m/day] Tunnel construction problems and design changes 2.0 1.5 1.0 0.5 original design 0.0 0 5'000 10'000 15'000 20'000 25'000 costs [€/m] Tunnel construction problems and design changes Trigoni Tunnel Carr. Sud L = 880 m Ap (silty clay) 120 m 80 40 0 new design advance rate = 0.3 m/day Tunnel construction problems and design changes A-A A 12-16 m 2.5 m 11 m C C 24 m 1.5 m A concrete invert length of round = 1 m bored piles of lean concrete C-C bored piles of lean concrete 13.7 m 1.35 m 1.5 m 1.35 m shotcrete and steel ribs Tunnel construction problems and design changes bottom of the bored piles 0.2 m uv uv uh1+uh2 uh1 uh2 new design tunnel convergences strongly reduced 0 monitoring stations in a distance of 24 m from the tunnel face Tunnel construction problems and design changes advance rate [m/day] 2.0 1.5 new design 1.0 0.5 original design 0.0 0 5'000 10'000 15'000 20'000 25'000 costs [€/m] Tunnel construction problems and design changes Gerace Tunnel Carr. Nord L = 553 m 120 m H=4–6m Sp (clayey sandy silt) Ap (clayey silt) 80 40 0 considered sections Tunnel construction problems and design changes Ap Trubi formation (clayey silt) granulometry 50% 0% Sp Trubi formation (clayey sandy silt) 100% 0% granulometry 50% 100% Sand Silt Clay Sand Silt Clay 90 90 60 60 c’ [kPa] c’ [kPa] 30 30 0 0 20 30 20 40 30 40 I’ [°] I’ [°] Tunnel construction problems and design changes B A grouted steel forepolings 9.8 m fiberglass bolts 12 1.25 A concrete invert length of round = 0.75 m A-A shotcrete and steel ribs 12 B installation every 12 m of advance 16 18 m 60-110 fiberglass bolts (density 0.5 - 0.9 bolts/m2) B-B (after exc.) 48 steel forepolings (spacing 0.2-0.4 m) Tunnel construction problems and design changes Face instability advance rate [m/day] Tunnel construction problems and design changes 2.0 1.5 1.0 0.5 original design 0.0 0 5'000 10'000 15'000 20'000 25'000 costs [€/m] Tunnel construction problems and design changes Gerace Tunnel Carr. Nord L = 553 m H=4–6m 120 m Sp (clayey sandy silt) Ap (clayey silt) 80 40 0 new design advance rate = 0.25 m/day Tunnel construction problems and design changes lean concrete A Steel reinf. I6 15x15 ground surface A-A 15.2 1.5 2 3.1 9.8 m 24-36 m 1.25 A concrete invert length of round = 1 m 14 m shotcrete and steel ribs Tunnel construction problems and design changes Carr. Sud Carr. Nord advance rate [m/day] Tunnel construction problems and design changes 2.0 1.5 new design 1.0 0.5 original design 0.0 0 5'000 10'000 15'000 20'000 25'000 costs [€/m] Conclusions Contractual obligations (construction time and costs) & uncertainties in the design phase flexibility in the execution phase