lorence mechanical excavations of urban rail unnels

FLORENCE, 15TH DECEMBER 2020

MECHANICAL EXCAVATIONSOF URBAN RAIL TUNNELS

FLORENCE HIGH SPEED RAILWAY UNDERPASS

Ing. Raffaele ZURLO

15th december 2020

CEO INFRARAIL FIRENZE

Copertina sezione- alternativa 2

Sottotitolo sezione

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PROJECT OBJECTIVES

[Testo livello 01] Inserire qui il testo corpo 20 pt





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4Progetto Infrarail Firenze I Raffaele Zurlo

TRAFFIC FLOW

THE RAILWAY HUB OF FLORENCE:

▪ 56% regional trains ▪ 29% long-distance trains ▪ 6% freight trains ▪ 7% technical trains TOTAL: 890 trains/day

REG

HS

IC

Freighttrains

Technicaltrains

TOTAL

100%

30% 70% 100%

ItinerariesonSMN ItinerariesnotonSMN Total

88% 12% 100%

73% 27% 100%

0% 100% 100%

78% 22% 100%

59% 41%

TRAFFIC DISTRIBUTION BY TRANSPORTATION TYPE AND ITINERARY

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CAPACITY ANALYSIS

CURRENT CRITICAL ISSUES:

1. Convergence of flows in thesame direction

2. Conflicts among traffic flowsin the opposite direction atthe Hub junction as well as atthe head station of SantaMaria Novella

Flows in the opposite direction

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CAPACITY ANALYSIS

CURRENT CRITICAL ISSUES:

1. Convergence of flows in thesame direction

2. Conflicts among trafficstreams in the oppositedirection at the Hub junctionas well as at the head stationof Santa Maria Novella

Traffic projections

+ 48%

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PROJECT FRAMEWORK

High Speed Railway Link for urban penetration

Total length: 7,819 mOperating speed: 100 km/hGradient : 17,94 ‰Standard tunnel section average surface:70 square meters

WORKS:

▪ 2 main single-track tunnels ▪ Transverse tunnels every 410 m▪ Belfiore High Speed Station

▪ Railway overpass

Lot 2

Lot 1

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NEW CONFIGURATION OF THE HUB

EXPECTED BENEFITS:

1. Reduction of transit times(about 15 minutes)

2. Separation between high-speed and regional trains

1. Greater availability of surfacetracks at Firenze Santa MariaNovella

2. Increased capacity andregularity of the Hub in favorof regional trains

Traffic projections

+ 48%

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IFR - Infrarail Firenze is a special-purpose company, set up inSeptember 2019 by RFI - ReteFerroviaria Italiana in order tocomplete the constructionproject of the Florence HighSpeed railway underpass and thenew High Speed Belfiore Station.

RFI & IFR

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INFRARAIL FIRENZE

Share capital€ 5,500,000

Human Resources

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Our missionImproving Florence urbanmobility and preserving

urban aesthetics by carryingout underground

infrastructure constructionworks and international

archistars’ projects

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GEOLOGY OF THE FLORENCE AREA

Lake deposits Lake depositsFirenze-Prato-Pistoia

Alluvial deposits

Recent deposits

Lake depositsFirenze-Prato-Pistoia

Progetto Infrarail Firenze I Raffaele Zurlo

Belfiore High Speed Railway Station

Campo di MarteSouth Entrance

RifrediNorth Entrance

Fortezza da Basso

Campo di MarteSouth EntranceFortezza da Basso


Rifredi North Entrance

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Alluvial deposits

Recent deposits





RifrediNorth Entrance

Fortezza da Basso


Fortezza da Basso

Belfiore High Speed Railway Station Rifredi

North Entrance

FLORENCE GROUNDWATER

Hydraulic Conductivity

+ 1,85m

+ 1,95m

+ 1m

- 0,8m

- 1,35m

-0,75m

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Alluvial deposits

Recent deposits



Campo di MarteSouth EntranceFortezza da Basso

Belfiore High Speed Railway Station Rifredi North

Entrance

FLORENCE GROUNDWATER

+ 0,8m

- 0,5m

+ 0,35m

- 0,35m

+ 1,4m

- 0,7m

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Confirmed by monitoring data, basically lower than expected values



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HIGH SPEED RAILWAY LINK

BOLOGNA ROMA

Lunghezza 1

Alt

ezza

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L= 2.115 m L= 3.006 mL= 453 m L= 1.317 m

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Railway UnderpassTunnel diameter: 9.43mTotal lenght: about 7 kmConnecting transversetunnels every 410m Tunnels inter-axis: 18m

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EPB (Earth Pressure Balance)


FLORENCE TBM Machine Type: TBM Earth Pressure Balance (EPB)

Total length (back up included)

111m

Total weight 14700kN

Radius capability 270m

Operating pressure

4 bar

Machine Type: TBM Earth Pressure Balance (EPB)

TBM Ref. Characteristics Value

Cutter Head

Boring Diameter 9,43 m

Weight 1390 kNNr. of Single Cutters 4+2 (peripheral)Nr. of Double Cutters 21Central Cutter nr 2 x 4 cutters Cutter Diameter 17"Nr. of Scrapers 124

Capability

Power 4530 kWTheoretical speed 80 mm/minMax Torque 28151 kNOperating Thrust 24429 kN

Shield

Front Max. diameter 9,40 mRear Max diameter 9,38 mTotal Length 10,085 mErector rot. speed loaded 1 r/min

Erector rot. speed unloaded 2 r/min

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FLORENCE TBMEPB (Earth Pressure Balance): OPERATING PRINCIPLES

Stability of the tunnel face →production of heavy slurry

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THE PRODUCTION CYCLE


Heavy slurry:Excavated soil + Additives

Foam→ Polyfoamer ECO/1002,25 l/m3 clay soils1,75 l/m3 sand soils

Water → 400 ÷ 500 l/m3

Polymers/Bentonite → 1 ÷ 3%

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In order to obtain an optimal slurry, it is necessary to use surfactants (foam)



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Prebuilt concrete segments are produced and installed in order to create the segmental lining, which must ensure stability and waterproofing of the cavity.



UNIVERSAL RINGThickness: 40cmStrenght class: C40/50Exposure class: XC2-XF1Steel: B450C

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The slurry is put on the conveyor belt and sent to the final storage by train



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PRODUCTION SITES

1.670.800 m3

(bulk)

52.500 m3

590.900

m3

677.400 m3

350.000 m3

Foaming agents with polymers

• Polyfoamer ECO/100 for type 1-soils (clay-loam)

• Polyfoamer ECO/100 and Mapedrill XG01 for type-2 soils

(gravelly loam soil - sand – clay) and for intermediate soils.

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SANTA BARBARA

Florence

S. Giovanni Valdarno

S. Barbara

1.670.800 m3

(bulk)

1.350.000 m3

Column ATable 1, part IV, attachment 5, title V of D.lgs. 152/2006

WasteAdrastea S.r.l.

Pomezia

621.000 m3

729.000

m3147.140 m3

Column «A»or

Column «B» surplusEx cava Bruni

Serravalle Pistoiese

22.000 m3

151.260 m3

180.000 m3 (supposed)

Characterization of mechanized-excavated soil

• Type 1-soils (clay): toxiciy test (day 28)

• Type-2 soils (gravel): toxicity test (day 14)

Surfactant > 15mg/KgToxicity level cannot be accepted (fish embryo toxicity test (FET) with the zebrafish (Danio rerio) and Aliivibrio fischeri Toxicity Tests (formerly Vibrio Fischeri)

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SANTA BARBARA

Progetto Infrarail Firenze I Raffaele Zurlo 23

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Waterproofing is ensured by the following elements:


Stability is ensured by the traditional structural elements:

STABILITY AND WATERPROOFING

• Segmental lining geometry

• Concrete and reinforcing steel characteristics

But especially…

• Back filling between the segmental lining and the soil

• Excellent quality of the concrete • Micro cracking to be avoided• Sealing elements and related positioning • Accurate installation of the segmental lining

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Prebuilt concrete segments are produced and installed in order to create the segmental lining, which must ensure stability and waterproofing of the cavity.



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THE INJECTION SYSTEMThe injection of concrete segments is fundamental to reduce subsidence and to ensure lining’s waterproofing

Back filling:Bicomponent resin

Component ACement 350 ÷ 400 kg/m3

Filler/Bentonite 45 ÷ 50 kg/m3

Water 800 l/m3

Component BSilicate based hardener 70% ÷ 80% (weight)

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SUBSIDENCE MONITORING

Andamento dei cedimenti attesi in condizioni di "green field" lungo il perimetro delle mura

0

0.005

0.01

0.015

0.02

0.025

0.03-10 40 90 140 190

Canna binario dispari Entrambe le canne Canna binario pari

A B C D

Bastione Rastriglia Cinta muraria Ovest

k = 0.35Vp = 0.4%

Bastione Rastriglia Cinta muraria Est Mura

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A

D

C

B

Expected subsidence <1,5cm

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SUBSIDENCE MONITORINGBoscardin e Cording (1989)

Category of damage Description of typical damage

0 - negligibleHairline cracks

Approx. Crack width 0.1 mm

1 - very slightFine cracks that can easily be treated during normal decoration

Approx. Crack width 1 mm

2 - slightCracks easily filled. Redecorating probably required


3 - moderate

The cracks require some opening up and can be patched by a mason.

Recurrent cracks can be masked by suitable linings. Repointing of external

brickwork and possibly a small amount of brickwork to be replaced.

Approx. Crack width 5-15mm or number of cracks >34 – severe Extensive repair work involving bricking out and replacing section of walls,

especially over doors and windows.

Approx. Crack width 15-25mm but also depends on number of cracks

5 – very severe This requires a major repair job involving partial or complete rebuilding.

Approx. Crack width usually >25mm but also depends on number of cracks

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Vp 0,4%

Vp 1%

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SUBSIDENCE – FORTEZZA DA BASSO

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Boscardin e Cording (1989)

Category of

damageDescription of typical damage

2 - slightCracks easily filled. Redecorating probably required


Intervento preventivoCompensation grouting.

MEMBRANE MIX❖ Cement class 425 type I÷IV - UNI197/1.❖ Water/cement ratio = 3.5❖ Filler/cement ratio = 1❖ Bentonite/water ratio = 2.0%❖ Density ≈ 1.32 t/m3

❖ Marsh funnel viscosity > 40÷45 s/l;❖ Volumetric efficiency after 4 hours: 98% (bleeding<2%);❖ Average composition/m3:• Cement ≈ 236 kg/m3;• Filler ≈ 236 kg/m3;• Water ≈ 827 lit/m3;• Bentonite ≈ 17 kg/m3.

PRE-TREATMENT MIX❖ Cement class 525 type I÷IV - UNI197/1.❖ Water/cement ratio = 4.0❖ Filler/cement ratio = 1❖ Bentonite/water ratio = 2.0%❖ Density ≈ 1.28 t/m3

❖ Marsh funnel viscosity 30÷40 s/l❖ Volumetric efficiency after 4 hours: 98% (bleeding<2%);❖ Average composition/m3:• Cement ≈ 210 kg/ m3

• Filler ≈ 210 kg/ m3

• Water ≈ 841 lit/ m3

• Bentonite ≈ 17 kg/ m3

• Additives ≈ 4 kg/ m3

❖ Injection parameters:• Injection pressure = 0.8÷1.1 Mpa• Injection rate = 5÷20 l/min

MITIGATION MEASURES MIX❖ Cement class 425 type I÷IV - UNI197/1.❖ Water/cement ratio = 2.0❖ Filler/cement ratio = 1❖ Bentonite/water ratio = 4.5%❖ Density ≈ 1.48 t/ m3

❖ Marsh funnel viscosity > 40÷45 s/l❖ Volumetric efficiency after 4 hours: 98%

(bleeding<2%);❖ Average composition/m3:• Cement ≈ 386 kg/ m3

• Filler ≈ 366 kg/ m3

• Water ≈ 733 lit/ m3

• Bentonite ≈ 15 kg/ m3

• Additives ≈ 4 kg/ m3

❖ Injection parameters:• Injection pressure = 1.5÷2.0 Mpa• Injection rate = 2 l/min

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SUBSIDENCE MONITORING

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NTC2018 UPDATE ORIGINAL DETAILED DESIGN DRAWN UP BETWEEN 2008 AND 2010

2020 – Railway stationn. 5 CH tests

2020

2020 - DH

2020 - CH

2020 - CH

2020 - DH

2020 - DH

2020 - DH

2020 - DH

2020 - DH

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NTC2018 UPDATE – SEISMIC ANALYSIS

Piano Comunale di Protezione Civile del Comune di Firenze. Attachments: C22 e C23

Most active seismic zone considered.(Intersection between zone S3*** and highest amplification values)

• Vu=100aa• Cu=2• Subsoil classes B, C and E• Coordinates: 43.783043; 11.235701

SLV B C E

ag [g] 0.203 0.203 0.203

Fo 2.407 2.407 2.407

TC [s] 0.316 0.316 0.316

SS 1.2 1.406 1.462

CC 3.85 1.536 1.824

ST 1 1 1

amax [g] 0.244 0.285 0.297

On a conservative prediction : amax = 0.297g

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Final coating checkThe seismic risk assessment has been carried out by a pseudo-static analysis (Bilotta et Al.)

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The seismic condition does not affectdimensioning, as the dynamic stresses occure on the same scale as the staticones. The related load combinations do notinvolve load increase (unitaryamplification factor).

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SUB-BALLAST MATS

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Thank you for your kind attention!

lorence mechanical excavations of urban rail unnels

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