Description of work Sicily Tunnel Caltanissetta Year: 2013 In progress Client: Anas s.p.a. Contractor: Empedocle 2 s.c.p.a. Total length: 28 km Works amount: 175.000.000,00 Activities: Construction design and technical assistance Main works: - 5 artificial tunnels - 4 natural tunnels - 13 viaducts - 10 overpasses Design speed: 70-120 Km/h Longitudinal slope: Max 4.2% Bending radius: Min. 800 m
Technical features Caltanissetta natural tunnel length Diameter Final inner diameter Cover about 3900m for each tube Ø15.08 m Ø13.60 m min.15 m max.130 m
Geomechanics tunnel profile SLN GER TRB TRVB GLT1 SLN - Lannari s sand GER - Geracello s marneous clay TRBA/B - Trubi GLT1 - Bedrock limestone TRVA/B - Marneous clay and clayey marne
Geotechnical tunnel data The following tables show the main parameters used in the project deriving from surveys along the route layout. Hydrogeological parameters Geotechnical parameters
Final design Excavation works using a TBM diameter 13,40 m + Stop emplacements every 600m obtained through traditional widening excavation More reinforcement D.M. 5/11/2001 Par. 4.1.2 According to italian D.M. 5/11/2001, tunnels longer than 1000m must have stop emplacements every 600m for each driving direction.
Modification for technical improvement Excavation works using a TBM diameter 15,08 m + Continuous hard shoulder D.Lgs. n 264/2006 Par. 2.5.3 If the construction features of the tunnel do not allow the realization of stop emplacements, or it turns out to be very expensive, then emplacements can be replaced with another lane.
THE ART METHOD ANALYSIS OF TECHNICAL RISK FOR THE TUNNEL PROJECT 1 2 3 THE ACQUISITION AND EVALUATION OF GEOLOGICAL AND GEOMECHANICAL DATA IDENTIFY AND EVALUATE THE PRINCIPAL RISK FACTORS AND THE DIVISION OF THE UNDERGROUND IN UNIFORM SECTIONS STATISTICAL PROCESSING OF SIGNIFICANT GEOTECHNICAL PARAMETERS Cost (euro) Area of responsibility of the Contractor times-costs 4 VARIABILITY PROGRESS SPEED OF TBM Time (day) 5 MONTE CARLO METHOD 6 GRAPHICAL REPRESENTATION OF TIME AND COSTS
State Route 640 ANALYSIS OF RISK ZONES ALTERNATIVE BETTER TECHNOLOGY FINAL DESIGN Tunnel realized with TBM (diameter of 15,08 m) Time % Time % Tunnel realized with TBM (diameter of 13,40 m) Cost % simulation excellent Cost % bad good simulation excellent bad good
ANALYSIS OF RISK ZONES Comparing tunnel with diameter 15,08 m and tunnel with diameter 13,40 m Time % Cost % Tunnel Tunnel Tunnel Time Cost Tunnel Time Cost
FINAL LINING PRECAST CONCRETE SEGMENTS - LOADS Casting the lining segments Removal of the forms Handling TBM trust Standard Assembly of ring Transport Assembly defect Storage Earth loads Fire loads Vibration The forces acting on the segments in a tunnel are the result of both transitory conditions such as those of the transport, placing and thrust of the jacks, and permanent forces such as the earth pressure when in service or the fire load generated as the result of an accident.
SEGMENTS FEM MODELLING TBM TRUST Finite element analysis (FEM) was performed on the stressstrain state under the different load conditions to which the prefabricated components are subjected during their normal life. In this situation the concrete segments are subjected to very strong loads which are borne under poorly defined conditions due to unavoidable irregularities in the plane in which they bear against the previous ring and to possible assembly faults already mentioned.
Analysis of the thrust phase under theoretical and therefore optimum conditions. SEGMENTS FEM MODELLING TBM TRUST In presence of assembly defects and/or exceptionally high thrust values. ASSEMBLY DEFECTS DEFORMATION DEFORMATION STRESS STRESS TRACTION TRACTION
CONCRETE SEGMENTS FIRE RESISTANCE POLYPROPYLENE FIBRES The polypropylene fibres low resistance to fire can be exploited as an advantage to reduce the problem of spalling in high strength concretes.
FIRE EXPERIMENT WITH THE BODY OF A CARRIAGE FROM LINE C OF THE ROME METRO An experiment was conducted at the Montelibretti school for fire-fighters designed to seek the best solution from the viewpoint of fire resistance and consequently of safety for tunnel users in cases of emergency.
FIRE EXPERIMENT WITH THE BODY OF A CARRIAGE FROM LINE C OF THE ROME METRO FIRE EXPERIMENT WITH THE BODY OF A CARRIAGE FROM LINE C OF THE ROME METRO The test tunnel was constructed, partly using prefabricated concrete some of which containing fibre additives, and partly using segments cast in situ in order to test different lining combinations. The design specifications for the part of the tunnel (14 segment rings) in which the carriage body to be sacrificed was positioned were as follows: 6 rings with completion of the upper half-ring cast in situ; 8 rings constructed using different types of concrete containing steel bars and/or polypropylene fibre additives; 7 rings starting from the centre protected with Fireshield the fire resistant mortar.
State Route 640 FINAL LINING PRECAST SEGMENTS RENFORCEMENTS PLAN CONTRAST TO EARTH LOADS FIRE LOADS SECTION B-B DETAILS CONTRAST TO TBM TRUST
THE TBM OPERATION STAGE 1. SHIELD 2. CUTTERS AND FOAM INJECTORS 3. EXCAVATION CHAMBERS UNDER PRUSSURE 4. HYPERBARIC CHAMBER 5. JACKS 6. AUGER FOR SPOIL REMOVAL 7. ERECTION SYSTEM 8. PRECAST SEGMENTS A TBM consists of a rotating cutterhead within a cylindrical steel shell that is pushed forward along the axis of the tunnel while excavating the ground through the cutterhead. The steel shield supports the excavated ground as required until the final tunnel lining is built in the rear of the shield. The shield is propelled using hydraulic jacks that thrust against the erected tunnel lining system. Earth Pressure Balance Machines (EPBMs) are shield machines specially designed for operation in soft ground conditions containing water under pressure Pressure-face TBMs that are capable of exerting a balancing pressure against the tunnel face are used to control excavation rates and groundwater inflow, as well as to maintain stability of the tunnel face.
State Route 640 THE TBM TBM FEATURES THE FEATURES SHIELD DIAMETER 15,03 m ROTATING HEAD 0-1,9 rpm MAXIMUM TORQUE 73.300 KNm MOTORS 21 JACKS 51 MAXIMUM THRUST 235.665 KN EXCEPTIONAL THRUST 269.330 KN MOTORS POWER 348 KW TOTAL POWER 7656 KW NUMBER OF CUTTERS 516 MAX WORKING PRESSURE 5,5 bar BACKUP 5 TRACKS BACKUP WEIGHT >850 TON
THE TBM FEATURES THE TBM FEATURES TBM pictures from the construction site.
State Route 640 MONITORING SYSTEM Natural tunnel Current section Special monitoring type 1(MS1) Natural tunnel Current section Special monitoring type 2(MS2) Natural tunnel Current section Final lining monitoring (MD) Cross section Legend Total pressure cell Strain gauges Piezometer