Metro Torino Extension - Design and construction problems

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Metro Torino Extension - Design and construction problems

  1. 1. Construction of the Turin MetroLine 1 Extension Marconi-LingottoCopenhagen, 18 June 2013Giorgio FantauzziProject Leader Tecnimont (Maire Tecnimont Group)Danish Society for Tunneland Underground Works
  2. 2. Infratrasporti.To S.r.l. is a company ownedexclusively by the City of Turin.The purposeof the company is: to own and manage existinginfrastructure to plan and construct new infrastructure,including railways for passenger andfreight transportation (both public andprivate)Infratrasporti.To S.r.l. owns Line 1 of theTurin Automatic Underground (13.2 km) andthe N. 4 Tramway line (18 km).The civil works design was governed by theVAL (Automated Light Vehicle) systemcharacteristics. The train is 2.08 m wide, 52m long and its maximum passenger capacityis 440 people (6 pass./m2).Base on width of train, a single 6.8 metersdiameter circular tunnel contains the doubletrack line has been chosen.The tunnel wasbored by TBM.LINE 1 EXTENSION METROTORINOGENERAL DESCRIPTION
  3. 3. Advantages of rubber wheels: Increased maximum slope (Easier track insertion in the city) Better acceleration/deceleration (Increased frequency of runs) Low vibrations and reduced noise (Better comfort)Advantages of VAL system: Metro stations with reduced size Smaller tunnel section compared to traditional metroLINE 1 EXTENSION METROTORINOVAL SYSTEMTraditional metrostation (RRT metro)150 m x 21mVAL typical station(LRT metro)54 m x16,4 mRRT – Rapid Rail TransitLRT – Light Rail TransitV0P.R. P.R.ASSEV1V2ASSE
  4. 4. 4Roma B1 – NATMexcavation double way(equivalent ø 11 m)Torino –TBM boredtunnel double way(ø 7.78 m)Copenhagen – TBM boredtunnel single way(ø 5.78 m)Linea Diametro CannaSuperficiesezione (mq)Volume perKM (mc)Confronto(mc)Linea 1 Torin 7,78 1 47,51 47.514,79 0Linea B1 Roma 11 1 94,99 94.985,00 47.470,21Linea 2 Copenhagen 5,78 2 52,45 52.451,19 4.936,39LINE 1 EXTENSION METROTORINOVAL SYSTEM
  5. 5. 5Tunnel 3.000 m tunnel bored using a TBM EPB (earth pressure balanced shield machines)Stations 6 stations (cut & cover) with diaphragms.First station (Marconi) has TBM job site and the last (Lingotto) has train interchange5 intermediate aeration shaft, built using micropilesShaftsLINE 1 EXTENSION METROTORINOCIVIL WORKS
  6. 6.  Unit 1 – superficial ground Unit 2 – gravel with sand from loose to slightly cemented Unit 3 – gravel with sand from weak to medium cemented Unit 4 - gravel with sand from medium to highly cemented.The tunnel excavation interested mainly unit 2 and 3. The ground water level varied from tunnel invert up to a maximum height of 7m measured at crown (Shaft n 6).LINE 1 EXTENSION METROTORINOGEOLOGY / GEOTECHNIC
  7. 7.  Utility relocation Job site alteration Diaphragms execution Station box execution Site cleaning and preparing for TBM TBM assemblyLINE 1 EXTENSION METROTORINOFIRST OPERATIONS
  8. 8. 8 Tecnological wires:• Electric• Telephonic Gas pipe Acqueducts Sewer Parking Monuments OtherLINE 1 EXTENSION METROTORINOUTILITY RELOCATION
  9. 9. LINE 1 EXTENSION METROTORINOGREEN MANAGEMENTSAnte-operam activities: Census of all the trees which could interfere with the works; Evaluation, for each tree, of the interference percentage; Evaluation of the possibility of maintaining the trees (properly protected bycrashes) in the area; Evaluation of the necessity of removing the trees; Definition of the removal intervention typology (cutting down or transplanting) inaccordance with species, dimension and phytopathological status Evaluation of the possibility of relocating the trees in original site, at the end ofthe works.The transplanting has been realized by special equipments in order to safeguard the trees radical planting and guarantee a correctrooting in the new site.
  10. 10. Criticality Short period between notice to award and operation; Saturated market bearings from eolic request; High risk of failure of procurement.LINE 1 EXTENSION METROTORINOEPB PROCUREMENTCountermeasures Market investigation about new TBM availability; Market investigation about used TBM availability; Risk plan to manage the acquisition.SolutionUsed TBM from job site in Paris with contingency plan forrefurbishment of machine.Previous projects: France – Tolosa 2003 -2005 Metro project [5.600m] France – Parigi 2006 – 2007 Water reservoir [1.800m]
  11. 11. Main refurbishment works: Bearing inspection and service Service of cutter-head Service of screw conveyor Change of belt Cylinder pressures tests Certification of tanks (water and oil) Certification of hyperbaric chamber Replacement of suctions sealing Replacement of cables Replacement of guidance and operation system Replacement of pressures cellsLINE 1 EXTENSION METROTORINOEPB PROCUREMENT
  12. 12.  Tunnel excavation diameter : 7.78 mt Ring external diameter : 7.48 mt Ring internal diameter : 6.88 mt Number of segments : 5 + 1 (key segment) Segments tickness : 30 cm Average segment length : 1.40 mt Minimum track radius: 261.8 mtLINE 1 EXTENSION METROTORINOTHE RING
  13. 13. Several methods employed on MetrotorinoMETHOD OF LECA & DORMIEUX (1990)This method is based on the upper and lower limit theorems with a 3D-modelling. The upper(+) and lower (-) limit solutions are obtained by means ofa cinematic and a static method, respectively, giving thus an optimistic and apessimistic estimation of the face-support pressure. In the case of drycondition, the face support pressure σT is (Ribacchi 1994):σT = – c’ · ctgϕ’ + Qγ · γ · D/2 + Qs · (σs + c’ · ctgϕ’)where Qγ, Qs = non dimensional factors (from normograms), function of H/aand ϕ’; a = radius of the tunnel; H = thickness of the ground above the tunnelaxis.METHOD OF JANCSECZ & STEINER (1994)According to the model of Horn (1961), the three-dimensional failure schemeconsists of a soil wedge (lower part) and a soil silo (upper part). The verticalpressure resulting from the silo and acting on the soil wedge is calculatedaccording to Terzaghi’s solution.A three-dimensional earth pressure coefficient ka3 is defined as:ka3 = (sinβ · cos · – cos2β · tanφ – K · α · cosβ · tanφ/1.5)/(sinβ · cosβ+ sin2β · tanφ)where:K ≈ [1 – sinφ + tan2(45 + φ/2)]/2;α = (1 + 3 · t/D)/(1 + 2 · t/D).METHOD OF ANOGNOSTOU & KOVARI (1996)This method, later referred to as A-K method, is based on the silo theory(Janssen 1895) and to the three-dimensional model of sliding mechanismproposed by Horn (1961). The analysis is performed in drained condition, and adifference between the stabilizing water pressure and effective pressure in theplenum of an EPBS is presented. If there is a difference between the waterpressure in the plenum and that in the ground, destabilizing seepage forcesoccur and a higher effective pressure is required at the face.However, accepting this flow, the total stabilizing pressure is lower than thepressure required in the case of an imposed hydrogeological balance. Theeffective stabilizing pressure (σ’) :σ’ = F0 · γ’ · D – F1 · c’ + F2 · γ’ · Δh – F3 · c’ · Δh/Dwhere F0,F1,F2,F3 are non-dimensional factors derived fromnormograms, which are function of H/D and ϕ’.LINE 1 EXTENSION METROTORINODESIGN PHASE - SUPPORT PRESSURE CALCULATION
  14. 14. MetroTorino [kPa]20wvakPPast experiences in Japan (from Kanayasu)METHOD OF DIN 4085 (GERMAN STANDARD)In this model, three-dimensional active earth pressure is calculated according to DIN 4085,which is based on the failure mechanism theory of Piaskowski & Kowalewski. The methoddivides the tunnel face into multiple horizontal strips. The three-dimensional active earthpressure acting on each strip is calculated with the two-dimensional active earth pressuremethod, adjusted by reduction factors. These factors are calculated depending upon the ratioof depth of the layer to tunnel diameter.To ensure stability of the tunnel face, it is necessary to counterbalance the total force of activeearth and water pressure. These forces are multiplied separately with safety factors as per theconcept of partial factor of safetyPsupport= η a E a + η w WWhere, η a and η w are partial factors of safety for active earth pressure (Ea) and waterpressure (W) respectively.Several methods employed on MetrotorinoDESIGN PHASE - SUPPORT PRESSURE CALCULATIONLINE 1 EXTENSION METROTORINO
  15. 15. 1020304050607080901001101201097 1147 1197 1247 1297Pressure[kPa]Chainage [m]Support pressure - Calculations using different methodsSpinta attiva KaSpinta a riposoKoDIN 4085Anagnostou &KovariLeca-DormieuxNormativaolandese COBJancsecz &SteinerPL2SHAFTNIZZASTATIONLINE 1 EXTENSION METROTORINODESIGN PHASE - SUPPORT PRESSURE CALCULATION
  16. 16. SENSOR LAYOUTWarning Pressure in workingchamberAttention Po = 0.9 Pd Po = 1.2 PdAlarm Po = 0.8 Pd Po = 1.3 PdLINE 1 EXTENSION METROTORINOCONSTRUCTION PHASE - SUPPORT PRESSURE MANAGEMENT
  17. 17. The main requirements a TBM should have to work in a urbanenvironment can be connected to:Suitability to the anticipated geological conditionsApplicability of supplementary supporting methods, if necessaryTunnel alignment and lengthEquipments to realize tests, surveys or additional treatmentsinwards;Availability of equipments necessary to control the excavationhead pressure;Availability of spaces necessary for auxiliary facilities behind themachine and around the access tunnelsInteraction with monitoring parameters;Safety of tunnelling and other related works.Assembling, maintenance and disassembling flexibility;Driving flexibility.LINE 1 EXTENSION METROTORINOEPB PROCUREMENTThe final choice of machine is always acompromise in which one of the keyparameters is the speed of excavation.
  18. 18. The correct project and development of the soil stability system is extremely important.To guarantee the pressure control at the head of the front and to allow the formation of amaterial easy to be extracted from the screw conveyor it is necessary to put conditioningagents in the excavated soil, such as bentonite, foaming agents, polymers and thin material.In our case, we wear the TBM with a separate circuit of emergency injection of bentonite toavoid loosing pressure and settlements.LINE 1 EXTENSION METROTORINOCONSTRUCTION PHASE - SUPPORT PRESSURE MANAGEMENT
  19. 19. SOIL CONDITIONIGLINE 1 EXTENSION METROTORINOCONSTRUCTION PHASE - SUPPORT PRESSURE MANAGEMENT
  20. 20. SLUMP TESTSLINE 1 EXTENSION METROTORINOCONSTRUCTION PHASE - SUPPORT PRESSURE MANAGEMENTSeveral tests were conducted onconditioned samples employing differentsproducts with different solutionpercentage (FIR; FER; etc..)
  21. 21. SCREW CONVEYOR EXTRACTION TESTLINE 1 EXTENSION METROTORINOCONSTRUCTION PHASE - SUPPORT PRESSURE MANAGEMENTAccording to EFNARC (”Specification andGuidelines for the use of specialistproducts for Mechanised Tunnelling “), thefollowing aspects need to be examined:• The plasticity of the soil, needed totransmit the pressure inside theworking chamber and along the screwconveyor• A low internal friction of thesoil, needed to reduce the torque of thecutterhead and the wear of the cutterinstruments• The persistence of the carachteristicsdescribed above over the time, to allowthe execution of operational procedures(ring mounting, stops notforeseen, etc..) in safer way.
  22. 22. SOIL CONDITIONINGLINE 1 EXTENSION METROTORINOCONSTRUCTION PHASE - SUPPORT PRESSURE MANAGEMENTNatural soilConditioned soilCONDITIONED SOILFER = 18FIR = 25%• Pressure transmissions are uniform and regular• Pressure is dissipated in regular way inside the screw conveyor• The thorque force is reduced
  23. 23. PENETRATION RATE [mm/min]PRESSURE SENSORS [Bar]SCREW CONVEYOR RATE [rpm]EXCAVATIONS PARAMETERSOver 100 parameters recorded by the automatic system.The main parameters to be verified via the sensors and sensingequipment, are:• Face-support pressure• Pressure and volume of the backfill grout of the annular void• Weight of the extracted materialEXCAVATION PHASEOPERATIONS – BUILDING RINGLINE 1 EXTENSION METROTORINOCONSTRUCTION PHASE - SUPPORT PRESSURE MANAGEMENT
  24. 24. Head support pression Penetration speedExtracted material weight Pression of the mortar injection ductsExample of TBM parameter monitoringLINE 1 EXTENSION METROTORINOCONSTRUCTION PHASE - SUPPORT PRESSURE MANAGEMENT
  25. 25. EPB –TBM OPERATION MODELINE 1 EXTENSION METROTORINOCONSTRUCTION PHASE - SUPPORT PRESSURE MANAGEMENT
  26. 26. END EXCAVATION PHASEEND EXCAVATION PHASEPRESSURIZED AIR/FOAM INFLOWSCREW CONVEYOR STOPPEDPRESSURE INCREASELINE 1 EXTENSION METROTORINOCONSTRUCTION PHASE - SUPPORT PRESSURE MANAGEMENT
  27. 27. Definition of normal and anomalous conditionsNormal excavating conditionsAll those conditions whose EPB excavation characteristic parameters fall within the “attention” thresholdsAnomalous conditions are associated with: Water inflows under pressure through the screw conveyor. Sudden oscillations of the torque of the cutterhead. Blockage of the cutterhead. Anomalous pressure values in the excavation chamber. Sudden and significant variations of the muck density in the excavation chamber. Weight of the muck extracted by the screw conveyor surpassing the “attention” threshold. Insufficient pressure and/or volume of the grout injected behind the lining.Pressure management in the work chamberSudden variations of the face-support pressure could be the warning signals resulting from torque increases or head blockages.In case the pressure increases: The head rotating speed is reduced to <1 rpm. The thrust is reduced so that penetration rate, Vp, is <10 mm/min. The foam flow is increased by 20%,without increasing the muck discharge from the screw.In case the pressure diminishes: Bentonite is injected to re-establish the design support pressure. If pressure still does not increase, excavation is stopped and the screw gate is closed. Bentonite and polymer injection is continued until the designed support-pressure is achieved.LINE 1 EXTENSION METROTORINOCONSTRUCTION PHASE - SUPPORT PRESSURE MANAGEMENT
  28. 28. WEIGHT MEASUREMENTSLINE 1 EXTENSION METROTORINOCONSTRUCTION PHASE - WEIGHT MANAGEMENTMaterial density was calculated as the average density measured on the last ten rings.Double weight measurement : Scales on belt Scales on wagonSpecial methodstatement, additionalinvestigationSOVRAESTRAZIONE STOPNOSIANALISI MATERIALEESTRATTOPeso del materiale estratto dalla coclea oltre ilimiti di allarme +/- 5%.INVESTIGAZIONE DAINTERNO GALLERIA -CAROTAGGIO CONCIOPRESENZA DIVUOTISIRIEMPIMENTODALL’INTERNO / INIEZIONESECONDARIANOREDAZIONE PROGRAMMAINVESTIGAZIONEDALL’ALTO (IM) EPERFORAZIONECASO B)INTERESSA DUE O PIÙ’ ANELLI CONSECUTIVIRIEMPIMENTO DALL’ALTO AGRAVITA’ CON MALTARIPRISTINO CONCIOSIVOLUME MALTA INIETTATA>VOLUME TEORICO PERFORAZIONEPERFORAZIONE INTERNOGALLERIA E INIEZIONE INPRESSIONERIPRISTINO CONCIOSovraestrazione misurata alla bilancia deL nastroconfermata da bilancia di controllo su: carroponte/carosello, sui cassoni.RITARATURA BILANCIA SUNASTRONOSISTOPSTOPNOVolume e pressione diiniezione maltasuperano le soglie diallarme inf. e sup.Volume e pressione diiniezione malta superanole soglie di allarme inf. esup.CASO A)INTERESSA UN SOLO ANELLO E VIENE BILANCIATA DASOTTOESTRAZIONE ANELLO SUCCESSIVONONOSTOPSISICASO A) O CASO B)DA DECIDERE IN CONTRADDITTORIO CON LA DIREZIONE LAVORI
  29. 29. The correct choice of the TBM is the first step to manage theexcavation. Then it s necessary to identify and define the otherequipments to be used, depending of job site conditions such as: Tower crane for materials feeding Electric fan for aeration 135 kW Cooling tower Gantry crane for lifting muck Trains or Dumper for segments feeding Water treatment plant (10 mc/h) Winch for conveyor belt Electrical transfomer 22.000/20.000 V Emergency electric generator 400 kW Mixers for mortar, compressorsLINE 1 EXTENSION METROTORINOEPB ANCILLARIES PLANTS
  30. 30. 30LINE 1 EXTENSION METROTORINOEPB ANCILLARIES PLANTS
  31. 31. LINE 1 EXTENSION METROTORINOEPB ANCILLARIES PLANTS
  32. 32. LINE 1 EXTENSION METROTORINOWORKSITE LAYOUT – STARTING SITE
  33. 33. Much removalLINE 1 EXTENSION METROTORINOWORKSITE LAYOUT – STARTING SITE
  34. 34. LINE 1 EXTENSION METROTORINOWORKSITE LAYOUT – STARTING SITE
  35. 35. LINE 1 EXTENSION METROTORINOWORKSITE LAYOUT – STARTING SITE
  36. 36. TBMTransport belt toTBM starting siteWagons and fixedcraneLoad andtransporttemporary areaSurfacetemporary depotDischarge andcreation of pilesin theoperational lotsTrasport to finaldestination36LINE 1 EXTENSION METROTORINOMUCK MANAGEMENT
  37. 37. 37 Two entrances and one lift for each station Station sizes 54x17m; Station deep from 20 to 25m;LINE 1 EXTENSION METROTORINOSTATIONS GEOMETRY
  38. 38. 38TOP DOWN SEQUENCELINE 1 EXTENSION METROTORINOSTATION CONSTRUCTION PHASES
  39. 39. UTILITY RELOCATIONLINE 1 EXTENSION METROTORINOSTATION CONSTRUCTION PHASES
  40. 40. UTILITY RELOCATIONLINE 1 EXTENSION METROTORINOSTATION CONSTRUCTION PHASES
  41. 41. UTILITY RELOCATIONLINE 1 EXTENSION METROTORINOSTATION CONSTRUCTION PHASES
  42. 42. SITE CLEANINGLINE 1 EXTENSION METROTORINOSTATION CONSTRUCTION PHASES
  43. 43. SITE CLEANINGLINE 1 EXTENSION METROTORINOSTATION CONSTRUCTION PHASES
  44. 44. EXECUTION OF GUIDE WALLSLINE 1 EXTENSION METROTORINOSTATION CONSTRUCTION PHASES
  45. 45. EXECUTION OF GUIDE WALLSLINE 1 EXTENSION METROTORINOSTATION CONSTRUCTION PHASES
  46. 46. EXCAVATION OF DIAPHRAGMSLINE 1 EXTENSION METROTORINOSTATION CONSTRUCTION PHASES
  47. 47. EXCAVATION OF DIAPHRAGMSLINE 1 EXTENSION METROTORINOSTATION CONSTRUCTION PHASES
  48. 48. REINFORCEMENTLINE 1 EXTENSION METROTORINOSTATION CONSTRUCTION PHASES
  49. 49. POURING OF CONCRETELINE 1 EXTENSION METROTORINOSTATION CONSTRUCTION PHASES
  50. 50. POURING OF CONCRETELINE 1 EXTENSION METROTORINOSTATION CONSTRUCTION PHASES
  51. 51. DEMOLITION OF TOP HEAD OFDIAPHRAGMSLINE 1 EXTENSION METROTORINOSTATION CONSTRUCTION PHASES
  52. 52. TOP SLAB REINFORCEMENTLINE 1 EXTENSION METROTORINOSTATION CONSTRUCTION PHASES
  53. 53. WATERPROOFINGLINE 1 EXTENSION METROTORINOSTATION CONSTRUCTION PHASES
  54. 54. EXCAVATION OF STATIONLINE 1 EXTENSION METROTORINOSTATION CONSTRUCTION PHASES
  55. 55. 55EXCAVATION OF STATION - USE OF STRUTSLINE 1 EXTENSION METROTORINOSTATION CONSTRUCTION PHASES
  56. 56. BOTTOM SLAB REINFORCEMENTLINE 1 EXTENSION METROTORINOSTATION CONSTRUCTION PHASES
  57. 57. TBM SUPPORTING SADDLELINE 1 EXTENSION METROTORINOSTATION CONSTRUCTION PHASES
  58. 58. DIAPRHAGM DEMOLITION FOR TBMSTARTLINE 1 EXTENSION METROTORINOSTATION CONSTRUCTION PHASES
  59. 59. PUSH PORTALLINE 1 EXTENSION METROTORINOTBM START
  60. 60. USE OF STEEL SEGMENT INSTATIONSLINE 1 EXTENSION METROTORINOTBM START
  61. 61. 61To avoid water inflowBottom groutingBreak Out TBMBreak In TBMLINE 1 EXTENSION METROTORINOSOIL IMPROVMENT
  62. 62. Soil improvement solutions have been implemented where theassessments indicate potential risk of damage to the pre-existingstructures. Such interventions include improving the properties of theground and mitigating the deforming effects induced by tunnelling bymeans of low-pressure cement injection grouting. A consolidated slabis created above the tunnel section in order to avoid any localizedinstability from developing around it.To reduce settlementsLINE 1 EXTENSION METROTORINOSOIL IMPROVEMENT
  63. 63. STRUCTURAL MONITORING TENSION (STRAIN GAUGES, LOAD CELLS, etc.) DEFORMATION, SETTLEMENT(INCLINOMETERS, OPTICAL TARGET, etc.)BE: Strain gaugeCTC: Optical targetIN: InclinometerLINE 1 EXTENSION METROTORINOMONITORING
  64. 64. 64LINE 1 EXTENSION METROTORINOMONITORINGBUILDING MONITORING
  65. 65. 65Automatic monitoring withelectrolevels : the distortionsmeasured during the excavationphase was less than theestablished trigger levelsExample of monitoring during the excavation of part of the work adjacent to the buildingsLINE 1 EXTENSION METROTORINOMONITORING
  66. 66. 66NOISEIn the following chart have been highlighted the referenceand results with the trends and the PM10 limits exceeding.AIRVIBRATIONThe noise monitoring campaigns was carried out on 20 receptors with: 39 measurements semi-fixed workstations; 41 measurements fixed workstations; 15 short period measurements, living environment.The vibration monitoring campaigns was realized on 14 receptors: 37 short period measurements 10 long period measurements (24 hours)LINE 1 EXTENSION METROTORINOMONITORING
  67. 67. Cleaning ofpavements wherethere is thevehicles transit;maintenance ofclearing brushes, etc.Optimization of pumpsacoustic insulation,etc.Monitoring campaignsComparison of the results obtained with thethreshold limitsThreshold limitsexceededThreshold limits metOpen af an anomaly:Analysis of the possible causes which producedthe criticality and prompt execution of themitigation interventions to solve and/or controlthe problems occurredExamples of mitigationintervention realizedLINE 1 EXTENSION METROTORINOENVIRONMENTAL PROCEDURE
  68. 68. LINE 1 EXTENSION METROTORINOCONSTRUCTION PROBLEMS – TOOLS UNDERPERFORMANCEEXCAVATION CHAMBER INSPECTION
  69. 69. First stretch Marconi - Nizza 96 tools added or changed More than 250.000 Euro damagesLINE 1 EXTENSION METROTORINOCONSTRUCTION PROBLEMS – TOOLS UNDERPERFORMANCE
  70. 70. Head at arrive in Nizza Station Head after refurbishmentLINE 1 EXTENSION METROTORINOCONSTRUCTION PROBLEMS – TBM HEAD DESIGN
  71. 71. LINE 1 EXTENSION METROTORINOCONSTRUCTION PROBLEMS – TBM HEAD DESIGN
  72. 72. Empirical methods are used to assess the settlements usingformulas that are based on empirical relations between availabledata. This data has been collected and assessed by a lot ofresearchers and for a lot of different projects.Peck (1969) was the first to propose that the surfacesettlement profile could be represented by a Gaussiandistribution curve.In Turin Metrovolume loss wasusually about0.3-0.5%LINE 1 EXTENSION METROTORINOBUILDING RISK ASSESSMENT
  73. 73. Paratie con solettone copertura e piano atrio di contrasto-2.0-1.5-1.0-0.50.0141516171819202122232425262728Distanza fondazioni-paratia [m]Cedimento[mm]LINE 1 EXTENSION METROTORINOBUILDING RISK ASSESSMENT
  74. 74. -3.7Volume perso [%] 1Diametro Galleria [m] 7.90Copertura [m] 10 0.00Parametro K 0.375 -0.85Distanza tra gli assi [m] 0 0.000309-Ascissa SX edificio [m] -24.4 0.036551Ascissa DX edificio [m] -9.4 0.00Altezza [m] 7.1Rapporto E/G 12.5 0.0462730.0000000.0504100.000.0504101EPS MAX flex hog 0.0007816EPS MAX flex sag 0.0016316EPS MAX tag hog 0.0006761EPS MAX tag sag 0.0014412Epsilon terreno Hogging [%]DATI DI INPUTCedimento massimo singola canna [cm]OUTPUTInterferenza n° 1000Cedimento vertice SX [cm]Cedimento vertice DX[cm]Rapporto /L zona di HoggingRapporto /L zona di SaggingCATEGORIA DI DANNOEpsilon terreno Sagging [%]Epsilon flessionale Hogging [%]Epsilon flessionale Sagging [%]EPSILON MASSIMAEpsilon Tagliante Hogging [%]Epsilon Tagliante Sagging [%]Deformazioni Epsilon [%]-0.5-0.4-0.3-0.2-0.100.10.2-20 -15 -10 -5 0 5 10 15 20Canna sxCanna dxTotaleCedimenti [cm]-4-3.5-3-2.5-2-1.5-1-0.500.5-20 -15 -10 -5 0 5 10 15 20Canna sxCanna dxTotaleSettlements calculation : Building damage assessmentLINE 1 EXTENSION METROTORINOBUILDING RISK ASSESSMENT
  75. 75. CASE HISTORYSettlements associated with buildings n 0973, 0974LINE 1 EXTENSION METROTORINOCASE HISTORY - SETTLEMENT ON BUILDINGS NEAR SPEZIA STATION
  76. 76. Buildings 973 - 974 : Masonry structures with directfoundations on stone wallsSITUATION «ANTE OPERAM»LINE 1 EXTENSION METROTORINOCASE HISTORY - SETTLEMENT ON BUILDINGS NEAR SPEZIA STATION
  77. 77. 973974973974MITIGATION MEASURES – SOIL INJECTIONSLINE 1 EXTENSION METROTORINOCASE HISTORY - SETTLEMENT ON BUILDINGS NEAR SPEZIA STATION
  78. 78. SETTLEMENTS DURING INJECTIONS PHASELINE 1 EXTENSION METROTORINOCASE HISTORY - SETTLEMENT ON BUILDINGS NEAR SPEZIA STATION
  79. 79. 79LINE 1 EXTENSION METROTORINOCASE HISTORY - SETTLEMENT ON BUILDINGS NEAR SPEZIA STATION
  80. 80. ADDITIONAL INVESTIGATIONSLINE 1 EXTENSION METROTORINOCASE HISTORY - SETTLEMENT ON BUILDINGS NEAR SPEZIA STATION
  81. 81. Presence of thick layers of silty-sandy-clay havingbehaviour "sensitive", with metastable microstructures sensitive to changes in stress or strains. The microstructuremetastable, stressed beyond a critical threshold level, it ceasesto behave in an elastic way, coming to be affected by phenomenaof destructuring, with significant loss of mechanical properties(generation of irreversible visco-plastic deformation ).In fact, it can be observed, that the oedometric curves referred atthe end of primary consolidation and 24 hours after the loadapplication are significantly different.ADDITIONAL INVESTIGATIONSLINE 1 EXTENSION METROTORINOCASE HISTORY - SETTLEMENT ON BUILDINGS NEAR SPEZIA STATION
  82. 82. DESTRUCTUREDSOILF.E. MODEL (PLAXIS SOFTWARE)LINE 1 EXTENSION METROTORINOCASE HISTORY - SETTLEMENT ON BUILDINGS NEAR SPEZIA STATION
  83. 83. NUMERICAL MODEL CALIBRATIONSETTLEMENT AFTER INJECTIONS PHASESETTLEMENT FROM F.E. MODELPREVISION FROM F.E. MODELSETTLEMENT AFTER TBM EXCAVATION -WITHOUT MICROPILES SHIELDSETTLEMENT AFTER TBM EXCAVATION -WITH MICROPILES SHIELDLINE 1 EXTENSION METROTORINOCASE HISTORY - SETTLEMENT ON BUILDINGS NEAR SPEZIA STATION
  84. 84. 974TtestTcritico25mTBM MANAGEMENTDuring the excavation of the testsection and the criticalsection, we had to give particularattention to the excavationsprocedures with reference to:Soil weight extracted from theTBM;Support pressure at the face;Grouting behind the segments(pressure and volume);Bentonite injections around theshield;Additional mitigations:Immediate availability of drillingequipment for investigations fromsurface.Possibility to execute radialinjections from the tunnel, at theend of shieldLINE 1 EXTENSION METROTORINOCASE HISTORY - SETTLEMENT ON BUILDINGS NEAR SPEZIA STATION
  85. 85. • Settlement during TBM excavation – Effects on stability of the buildingsEXCAVATIONMANAGEMENTMECHANIZEDEXCAVATIONMONITORINGSTOP EXCAVATIONMONITORING > L alertMONITORING OKEXPERTS COMMITEE(CONTRACTOR;OWNER;CONSULTANTS)NEW PROCEDURENEW COUNTERMESURESWork Procedure - TtestLINE 1 EXTENSION METROTORINOCASE HISTORY - SETTLEMENT ON BUILDINGS NEAR SPEZIA STATION
  86. 86. EXCAVATIONMANAGEMENTMECHANIZEDEXCAVATIONMONITORINGSTOP EXCAVATION(with workingchamber in pressure)MONITORING >LalarmMONITORING OKNEW PROCEDURENEW COUNTERMESURESBUILDINGSEVACUATIONMONITORING >LalertMANAGEMENTOWNER, MUNICIPALITY.Work Procedure - TcriticoLINE 1 EXTENSION METROTORINOCASE HISTORY - SETTLEMENT ON BUILDINGS NEAR SPEZIA STATION
  87. 87.  Topographic leveling executed 3 times a day (6:00 am - 14:00 -22:00). Monitoringdata available two hours after the end of leveling. Clinometers and crackmeters (manual readings) recorded once a day. Installation of 12 crackmeters (automatic readings) to monitor effects induced by TBMexcavation on existing cracks in "real time“ The reading of the total station has take place every 30 minutes and the return on the GISplatform with a frequency of 1 hour. Monitoring data available at the end of each ring excavation. It has been installed n.2 vibrometers on buildings 0973, 0974MONITORINGLINE 1 EXTENSION METROTORINOCASE HISTORY - SETTLEMENT ON BUILDINGS NEAR SPEZIA STATION
  88. 88. MONITORINGLINE 1 EXTENSION METROTORINOCASE HISTORY - SETTLEMENT ON BUILDINGS NEAR SPEZIA STATION
  89. 89. Example: existing sanitary sewerLINE 1 EXTENSION METROTORINOCASE HISTORY - INTERFERENCES WITH THE SEWERS
  90. 90. Interferences with subservicesExample: existing sanitary sewerLINE 1 EXTENSION METROTORINOCASE HISTORY - INTERFERENCES WITH THE SEWERS
  91. 91. Interferences with subservicesExample: existing sanitary sewerLINE 1 EXTENSION METROTORINOCASE HISTORY - INTERFERENCES WITH THE SEWERS
  92. 92. Interferences with subservicesExample: rain water sewerLINE 1 EXTENSION METROTORINOCASE HISTORY - INTERFERENCES WITH THE SEWERS
  93. 93. LINE 1 EXTENSION METROTORINOCASE HISTORY - INTERFERENCES WITH THE SEWERS
  94. 94. LINE 1 EXTENSION METROTORINOCASE HISTORY - INTERFERENCES WITH THE SEWERS
  95. 95. LINE 1 EXTENSION METROTORINOCASE HISTORY - SHAFT CONSTRUCTION
  96. 96. LINE 1 EXTENSION METROTORINOCASE HISTORY - SHAFT CONSTRUCTION
  97. 97. Problems during construction:• Flood in shaft – Effect on tunnel connectionLINE 1 EXTENSION METROTORINOCASE HISTORY - SHAFT CONSTRUCTION
  98. 98. Problems during construction:• Flood in shaft – Effect on tunnel connectionLINE 1 EXTENSION METROTORINOCASE HISTORY - SHAFT CONSTRUCTION
  99. 99. INITIAL SITUATIONLINE 1 EXTENSION METROTORINOCASE HISTORY - FLOOD IN DANTE STATION…AFTER FEW HOURS
  100. 100. • Flood in station – Effects on TBM scheduleLINE 1 EXTENSION METROTORINOCASE HISTORY - FLOOD IN DANTE STATION
  101. 101. Problems during construction:• TBM in/out does not perform – Effects on stability, flood in station and launch of TBMTests to check permeability value TBM In - Supplementary injections to reducewater inflowLINE 1 EXTENSION METROTORINOCASE HISTORY - BREAK IN / OUT
  102. 102. Problems during construction:• TBM in/out does not perform – Effects on stability, flood in station and launch of TBMTBM Out - Supplementary injections TBM Out – Sealing System to start excavationLINE 1 EXTENSION METROTORINOCASE HISTORY - BREAK IN / OUT
  103. 103. LINE 1 EXTENSION METROTORINOCASE HISTORY - NICHE CONSTRUCTION
  104. 104. Tunnelling is not a risk-free technology, each tunnel is a specific unique project on its own in a unique combination ofground / soil. The “right” construction method with the “right” experience parties involved are crucial for the success.The main most important factor however, the geology, is only known to a limited extent. Any accident during construction as wellas in use provokes a substantial interruption and often a standstill till the problems are solved.Risk has two components: probability of occurrence W and amountof damage D.The different steps of the process are: Identification of the risks (initial one); Reduction of the initial risk working on the impact and/orpossibility of occurrence of an event (i.e. provisional buildingworks, choice of the machinery, control of the TBM headpression); Management of the residual risk (i.e. monitoring).Residual risks are unavoidable and they should be sharedamong the Parties and systematically controlled bycountermeasures.LINE 1 EXTENSION METROTORINOCONCLUSIONS
  105. 105. The residual risk have to be managed during the constructionphase by means of an integrated monitoring system to: Check the hypothesis used during the desig ohase; Allows to understand the atypical phenomena giving theinformation necessary to solve the problem.The project must define two parameters which identify the“attention” and “alarm” levels.Attention level activates a specific control system in order toreach a more specific following of the event.Alarm level requires the adoption of the counter-measuresspecifically studied for the event.Topographical controls on buildingsLINE 1 EXTENSION METROTORINOCONCLUSIONS
  106. 106. The extension of MetroTorino has take account of a multidisciplinary approach thatconsiders all the processes of the entire lifecycle and performance of the works.The integrated methodological approach, implemented in the execution of projects andworks of construction into urban areas, must necessarily involve the adoption of a process ofcontinual revision of the initial assumptions of the design, through the continuousanalysis of monitoring data for proper risk management.LINE 1 EXTENSION METROTORINOCONCLUSIONS
  107. 107. START: 08.01.2007Finishing date (CONTRACTUAL) : 03.05.2010Finishing date (REAL) : 03.02.2010LINE 1 EXTENSION METROTORINOAWARDS
  108. 108. RomeVia di Vannina, 88/9400156 RomePh. +39 06 4122 351Fax +39 06 4122 35610MilanViale Monte Grappa, 320124 MilanPh. +39 02 6313.1Fax. +39 02 6313.9052TurinCorso Ferrucci, 112/a10138 TurinPh. +39 011 00.56.1Fax +39 011 00.56.444FlorenceViale L. Ariosto 24/b50124 FlorencePh. +39 055 2280 609Fax +39 055 2335 517info@mairetecnimont.it – www.mairetecnimont.it

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