nz course tunnelling - amazon web services general remarks any tunnelling activity causes ground...

An NZGS 1 day short course

Ground movement control

Tunnelling

Antonio GensTechnical University of Catalonia, Barcelona, Spain

Introduction Ground movements generated by tunnelling Procedures for ground movement control

General Tunnelling procedure (TBMs) Screen (curtain) walls Structural movement compensation Compensation grouting

Final remarks

Outline

Introduction

General remarks Any tunnelling activity causes

ground movements Ground movements must be

controlled to ensure that they are within requirements

In the last few years, there is an increasing sensibility of public opinion concerning ground movements caused by civil engineering works, especially tunnelling and deep excavations

This lecture focuses on ground movements caused by tunnelling

Introduction

Ground and foundation movement Rotation or slope, Angular strain (distortion), Relative deflection, Deflection ratio, /L Tilt, Relative rotation Average horizontal strainh=l/L

Introduction Damage criteria

Boscardin & Cording (1989)

Introduction Damage criteria

Burland et al. (1977)

Damage criteria

Burland (1998)

Introduction

Damage criteria

Boscardin & Cording (1989) Burland (1998)

Introduction

Tunnelling methods

Open-face tunnelling

NATM or SCL

Tunnelling methods

Closed-face tunnelling

Slurry shield (SS)

Earth pressure balance (EPB)

Tunnelling methods

Selection of closed-face tunnelling method

Tunnelling methods

Movements caused by tunnel instability



Final remarks

Outline

Ground movements caused by tunnelling Settlement trough

Ground movements caused by tunnelling Ground movements generated by (closed-faced) tunnelling

Components of ground movement Deformation of the ground towards the face resulting from stress

relief Passage of the shield, effect of overcutting edge (plus machine

plough or yaw) Tail void, ground filling the gap around the lining Deflection of the lining as ground loading develops Consolidation movements (pore pressure dissipation + drainage)

Ground movements caused by tunnelling Ground movements generated by (open-faced) tunnelling

Components of ground movement Deformation of the ground towards the face resulting from stress

relief Passage of the shield, effect of overcutting edge (plus machine

plough or yaw) Tail void, ground filling the gap around the lining Deflection of the lining as ground loading develops Consolidation movements (pore pressure dissipation + drainage)

D

/4DπV VL loss Volume 2

s

yi

s

Inflection pointSettlement

maxs s i 2πV Volume

2

2

max 2iyexpss

smax

Ground movements caused by tunnelling Settlement trough: volume loss

2

max 32Ds VLi

Ground movements caused by tunnelling Settlement trough width

D

yi

s

Inflexion pointSettlement

smax

D

yi

s


smaxz0

Peck (1969)

Ground movements caused by tunnelling Settlement trough width: clays

D

yi

s


smax

D

yi

s


smaxz0

Mair & Taylor (1997)

oi Kz

K = = 0.5 in claysO’Reilly & New (1982)

Ground movements caused by tunnelling Settlement trough width

D

yi

s


smax

D

yi

s


smaxz0

oi Kz

K = 0.25 in sandsMair & Taylor (1987)

O’Reilly & New (1982)

Ground movements caused by tunnelling Subsurface movements

Mair et al. (1993)Clays

Sands

0.175 0.325(1 / )1 /

o

o

z zKz z

Ground movements caused by tunnelling Horizontal movements

Attewell (1978) O’Reilly & New (1982)

0h v

ys sz

2

2max

1.65 exp2

h

h

s y ys i i


Hong & Bae (1995)

NATM in sands

Ground movements caused by tunnelling Development of ground movements

Attewell & Woodman (1982) suggested using the cumulative probability curve 21( ) exp( / 2)

2( ) 1 ( )

G d

G G

Ground movements caused by tunnelling Development of ground movements

Moh et al. (1996)

EPB tunnelling in silty sands in Taipei EPB tunnelling in sands in Cairo

Ata (1996)

Ground movements caused by tunnelling Typical ground losses:

Open faced tunnelling: 1% - 2% in stiff clay (London clay). NATM in London clay: 0.5%-1.5%

Closed-face tunnelling around 0.5%. In soft clays 1% - 2% Beware of mixed face situations or when granular/fill lies on top of the

tunnel

Madrid Metro observations

Ground movements caused by tunnelling Consolidation movements

Generation of pore water pressures Overpressurization of the face High tail void grouting pressures

Hwang et al. (1995)

EPB tunnelling in soft silty clay in Taipei

Ground movements caused by tunnelling Consolidation movements: two sources

Dissipation of pore water pressures generated: trough width similar to the short-term one

Tunnel lining acting as a drain: wide settlement trough

Shirlaw (1995)

Long term settlement troughs for tunnels in soft clays

Immediate and post construction settlements in London clay

Bowers et al. (1996)

Ground movements caused by tunnelling Effect of the stiffness of the building

Treasury building and St. James greenfield site

Viggiani and Standing (2001)


Based on (nonlinear) finite element analysis

Addenbrooke and Potts (1997)

2*( / 2)s

EIE B


Based on (nonlinear) finite element analysis

Modification factors for deflection ratio

Addenbrooke and Potts (1997)

Modification factors for horizontal strain

2*( / 2)s

EIE B

*( / 2)s

EAE B

Ground movements caused by tunnelling

Modification factors for deflection ratio

(Franzius et al., 2006)

Modification factors for horizontal strain

*mod 2

0s

EIE z B L

Effect of the stiffness of the building Based on more finite element analysis including 3-D analyses, building

weight, building width, interfaces.

*mod

s

EAE BL

Ground movements caused by tunnelling Assessing the risk of building damage: The Jubilee line procedure

(Burland et al., 2002) Three stages of assessment:

Preliminary assessment: a simple and conservative approach, check settlement less than 10 mm and less the 1/500

Second stage assessment: make use of “greenfield”empirical predictions and damage criteria. The stiffness of the building may be taken into account but is it not often done

Detailed evaluation for those buildings classifies as being at risk of category 3 damage or greater. If confirmed, design remedial measures (MGT)

Jubilee line, accepted category damage: 2 There is a tendency to reduce the category of accepted damage

In Barcelona Metro and High speed train tunnelling, accepted damage category is 0!



Final remarks

Outline

Structural measures Deep and shallow

underpinning Increase tensile capacity Reducing sensitivity of the

structure Structure jacking Barrel vaulting

Procedures for ground movement control

In-tunnel measures Tunnelling method / TBM

design Face support measures Excavation in parts Mechanical pre-cutting Barrel (umbrella) vaulting

(adapted from Harris, 2001)

Ground treatment Compensation grouting Ground improvement:

permeation grouting, jet grouting, compaction grouting, freezing

Inserting structural elements screen or curtain walls steel pipes

Drainage and control of ground water

In-tunnel measures


In-tunnel measures: barrel vaulting and excavation by parts


(Harris, 2001)

Structural measures Deep and shallow

underpinning Increase tensile capacity Reducing sensitivity of the

structure Structure jacking Barrel vaulting


In-tunnel measures Tunnelling method / TBM

design Face support measures Excavation in parts Mechanical pre-cutting Barrel (umbrella) vaulting

(adapted from Harris, 2001)

Ground treatment Compensation grouting Ground improvement:

permeation grouting, jet grouting, compaction grouting, freezing

Inserting structural elements screen or curtain walls steel pipes

Drainage and control of ground water



Final remarks

Outline

Closed shield machine. Earth pressure balance TBM (EPB)

Tunnelling procedure TBM

West Portal

Stratford BoxMade Ground & Terrace Gravel

Groundwater table in upper aquifer

Groundwater table in lower aquifer

London Clay

Woolwich & Reading Beds

Upnor FormationThanet Sand

Chalk

Chainage (m)

Elev

atio

n(m

)

40

3020

10

0-10-20

-30

-40

King’s Cross

Tunnelling procedure Geology of Channel Tunnel Rail Link (C220)

7.4 km of twin tunnels of 8.1 m diameter

Tunnelling procedure Face pressure control Channel Tunnel Rail Link (C220)

London clayLambeth group

(Borghi & Mair, 2006)

WRB+UF

TS+UF

Thanet Sand (TS)TS+Chalk

Woolwich and Reading Beds(WRB)

WRB+HFWRB+HF+LC

London Clay (LC)0

0.20.40.60.81.01.21.4

1000 3000 5000 7000 9000Chainage (m)

Volu

me

loss

(%)

Stratford BoxWest Portal

Control de movimientos causados por túneles Volume loss CTRL C220 (Wongsaroj et al., 2005)

Acknowledgments to R.J. Mair

Barcelona Metro: Line 9

27.2 km: 12.3 m diameter tunnel 11.9 km: 9.4 m diameter tunnel 5.0 km: cut and cover tunnel

0.9 km: mined tunnel 2.8 km: viaduct

TOTAL: 47.8 km (52 stations)


Mixed mode TBM 11,95m dia.

EPB 12,06m Ø dia. (2)

EPB 9,40m dia. (2)

TBMs used


Soil profile in the Llobregat delta


EPB Mas Blau- MercabarnaDiameter 9.4 m

0,0

0,5

1,0

1,5

2,0

2,5

3,0

3,5

‐1000 ‐500 0 500 1000 1500

Distance (m)

Gro

und

loss

(%)


EPB Mas Blau- Aeroport EPB Mas Blau- Mercabarna

Volume loss

IVIII

II

I


Volume loss

VS(%)= ‐0.13 Pk 6415‐6531

Vs(%)= 0.02Vs(%)= 0.02

Vs(%)= 0.13Vs(%)= 0.13

Vs(%)= 0.36Vs(%)= 0.36

Pk 6548

Pk 6583

Pk 6621‐6993

VS(%)= 1.00VS(%)= 1.00 Pk 6624

Vs(%)= 0.58Vs(%)= 0.58Pk 6999‐7068

VS(%)= 0.86 Pk 7083‐7158

VS(%)= 0.56 Pk 7181‐7217

VS(%)= 0.14VS(%)= 0.14 Pk 7222‐7231

Pk 7249 Vs(%)= 0.82Vs(%)= 0.82 VS(%)= 0.48VS(%)= 0.48 Pk 7249‐7586

VS(%)= 0.21 Pk 7654‐7845

Vs(%)= 0.45Vs(%)= 0.45Pk 7934

Vs(%)= 0.28Vs(%)= 0.28Pk 811‐8319 Pk 8357

VS(%)= 1.09VS(%)= 1.09Pk 8380

VS(%)= 1.5VS(%)= 1.5 Pk 8400

VS(%)= 0.77VS(%)= 0.77 Pk 8427

VS(%)= 0.24VS(%)= 0.24 Pk 8448‐8482

VS(%)= 0.79VS(%)= 0.79

VS(%)= 0.40VS(%)= 0.40Pk 8494‐8521

VS(%)= 0.34VS(%)= 0.34Pk 8583‐8700

UPDATED 02/10/2009

VS(%)= 0.55VS(%)= 0.55Pk 8720‐8760

VS(%)= 0.21VS(%)= 0.21 Pk 8780‐8906

P1 = Face pressureP2 = Shield pressureP3 = Grouting pressure

Face pressure

Shield bentonite pressure

Grouting pressure in the annulus between

soil and lining

EPB tunnelling Tunnelling pressures

53EPB tunnelling Bentonite injection through the shield

SHAFTSHAFT

EPB tunnelling Recorded grouting pressure, P3

EPB tunnelling Volume loss before passage of EPB (ahead of face)

EPB tunnelling Effect of grouting pressures on total volume loss

Shield pressure, P2 Grouting pressure, P3



Final remarks

Outline

Quaternary Sandy silt

with gravel

Miocene Stiff clay matrix

with boulders

Fill

Salvador Seguí street

Screen (curtain) walls Jet-grouting screen

Jet grouting screen: ground movements

-10-8-6-4-202468

1012

-40 -20 0 20 40

Distance from tunnel axis [m]

Verti

cal d

ispl

acem

ent [

mm

]

Jet GroutingPassage of EPBFinal

PK 4+800

-10-8-6-4-202468

1012

-40 -20 0 20 40


Verti

cal d

ispl

acem

ent [

mm

] Jet GroutingPassage of EPBFinal PK 4+770


0

5

10

15

20

25

30

35

40

45

0 2 4 6 8 10Horizontal displacement (mm)

Dep

th (m

)

Observed

Numerical Analysis (with JG)

0

2

4

6

8

10

12

14

16

18

20

-14-12-10-8-6-4-20

Vertical displacement (mm)

Dep

th (m

)

Observed

Numerical analysis (with JG)

PK 4+7750

5

10

15

20

25

30

35

40

45

-5 5 15 25 35 45Distance [m]

Dep

th [m

] ExtensometerPiezometerInclinometerPrecise level point

A B



0

5

10

15

20

25

30

35

40

45

0 2 4 6 8 10Horizontal displacement (mm)

Dep

th (m

)

Observed

Numerical Analysis (with JG)

Numerical analysis (no JG)

0

2

4

6

8

10

12

14

16

18

20

-14-12-10-8-6-4-20

Vertical displacement (mm)

Dep

th (m

)

Observed



PK 4+7750

5

10

15

20

25

30

35

40

45

-5 5 15 25 35 45Distance [m]

Dep

th [m

] ExtensometerPiezometerInclinometerPrecise level point

A B



-7

-6

-5

-4

-3

-2

-1

0-50 -40 -30 -20 -10 0 10 20 30 40 50


Verti

cal d

ispl

acem

ent [

mm

]

Observed


SettlementsPérdida de volumen, Vl,reducida de 0.35% a 0.27%

Jet grouting screen: ground movementsJet grouting screen: ground movements


-7

-6

-5

-4

-3

-2

-1

0-50 -40 -30 -20 -10 0 10 20 30 40 50


Verti

cal d

ispl

acem

ent [

mm

]

Observed



SettlementsVolume loss reduced from 0.35% to 0.27%



Sant Adrià street

Screen (curtain) walls Pile screen wall

Sant Adrià street

Sand (alluvial)

Fill

Silt (alluvial)

Sand and gravel (alluvial)

Pleistocene

Water table

Pile screen wall

Sant Adrià street

Pile screen wall

Surface settlement on tunnel axis

-90

-80

-70

-60

-50

-40

-30

-20

-10

0

10

27/0

2/20

05

09/0

3/20

05

19/0

3/20

05

29/0

3/20

05

08/0

4/20

05

18/0

4/20

05

28/0

4/20

05

08/0

5/20

05

18/0

5/20

05

28/0

5/20

05

07/0

6/20

05

Date

Vert

ical

mov

emen

t [m

m]

T4B02973E000HN007WP

assa

ge o

f EP

B

Pile screen wall

Surface settlements

-90

-80

-70

-60

-50

-40

-30

-20

-10

0-60 -40 -20 0 20 40 60


Gro

und

vert

ical

dis

plac

emen

t [m

m]

Observed

Pile screen wall

-90

-80

-70

-60

-50

-40

-30

-20

-10

0-60 -40 -20 0 20 40 60


Gro

und

vert

ical

dis

plac

emen

t [m

m]

Observed

Hypothetical displacement profile with noBPW

Surface settlements

Pile screen wall

PK 2+973Sant Adrià street

0

5

10

15

20

25

30

35

-100 -90 -80 -70 -60 -50 -40 -30 -20 -10 0 10Vertical displacement [mm]

Dep

th [m

]

Observed

Numerical analysis (with BPW)

Numerical analysis (no BPW)

0

5

10

15

20

25

30

35

-100 -90 -80 -70 -60 -50 -40 -30 -20 -10 0 10Vertical displacement [mm]

Dep

th [m

]

Extensometer at tunnel axis



Vertical displacements

Pile screen wall

PK 2+973

0

5

10

15

20

25

30

35

40

45

-30 -20 -10 0 10 20 30 40 50Horizontal displacement [mm]

Dep

th [m

]

Inclinometer at 10m (L) from tunnel axis



0

5

10

15

20

25

30

35

40

45

-30 -20 -10 0 10 20 30 40 50Horizontal displacement [mm]

Dep

th [m

]

Observed



Sant Adrià street

Horizontal displacements

Pile screen wall

-90

-80

-70

-60

-50

-40

-30

-20

-10

0-60 -40 -20 0 20 40 60


Gro

und

vert

ical

dis

plac

emen

t [m

m]

Observed

Numerical analysis (with Bored Pile Wall)

Surface settlements

Pile screen wall

Surface settlements

-90

-80

-70

-60

-50

-40

-30

-20

-10

0-60 -40 -20 0 20 40 60


Gro

und

vert

ical

dis

plac

emen

t [m

m]

Observed

Numerical analysis (with bored pile wall)


Volume loss, Vlreduced from 1.90% to

1.68%

Pile screen wall

Burland-0.35

-0.30

-0.25

-0.20

-0.15

-0.10

-0.05

0.000.00 0.05 0.10 0.15 0.20 0.25 0.30 0.35

Horizontal tensile strain [%]

Def

lect

ion

ratio

[%]

Building (Case with BPW)

Building (Case with no BPW)

0

1

CATEGORY 2

CATEGORY 3 DAMAGE

CATEGORIES 4 AND 5 DAMAGE

PK 2+973Sant Adrià street

Pile screen wall

No pile screen wall

Pile screen wall

El Periódico

A tunnel close to the Sagrada Familia church (Barcelona) Building scheme

4.2 m

8.8m

12.0 m

11.1 m

31.5

m

17 m

A tunnel close to the Sagrada Familia church (Barcelona) Building scheme: cross section



Final remarks

Outline

Structure jacking Advantages

Very precise control of settlement is possible

The system is useful in areas with potentially steep settlement gradients

The jacks can be use to produce settlements or heave

Disadvantages Complexity Reaction time may be slow

specially for heavy structures

Structural movement compensation

Twin tunnels in Waterloo station (Jubilee Line Extension)

(Harris, 2001)

Cross section


Lifting points in the structure (flat jacks)


Low level tunnels constructedUpper level tunnels

constructed

-0.01

0

0.01

0.02

0.03

0.04

0.05

01/0

1/19

95

02/0

3/19

95

01/0

5/19

95

30/0

6/19

95

29/0

8/19

95

28/1

0/19

95

27/1

2/19

95

25/0

2/19

96

25/0

4/19

96

24/0

6/19

96

23/0

8/19

96

22/1

0/19

96

21/1

2/19

96

19/0

2/19

97

20/0

4/19

97

Settl

emen

t (m

)

Pier A North (above jacks)

Pier A North (below jacks)

Low level tunnelsconstructed Upper level tunnelsconstructed

Settlements below the jacks

Settlements above the jacks


Twin tunnels in Waterloo station (Jubilee Line Extension)

Medium to coarse sands

Gravels with sand/silt matrix

SiltSilty gravel

Tunnel

Passage of Line 9 below an urban motorway


B-10 motorway


Distribution of vertical movements measured in subhorizontal inclinometers

B-10 motorway


Surface and structure settlements

B-10 motorway

Central pierAbutment wall

-50

-40

-30

-20

-10

0

10

05/1

3/20

04

06/0

2/20

04

06/2

2/20

04

07/1

2/20

04

08/0

1/20

04

08/2

1/20

04

09/1

0/20

04

Time

Vert

ical

dis

plac

emen

t [m

m]

StructureSoil surface

Pas

sage

of E

PB

Micropiles

Jacking

-50

-40

-30

-20

-10

0

10

05/1

3/20

04

06/0

2/20

04

06/2

2/20

04

07/1

2/20

04

08/0

1/20

04

08/2

1/20

04

09/1

0/20

04

Time

Vert

ical

dis

plac

emen

t [m

m]

StructureSoil surface

Pass

age

of E

PB

Micropiles

Jacking




Final remarks

Outline

Settlement control by displacement grouting

Corrective grouting (jacking)Grouting is performed after

settlement has occurred

Compensation groutingGrouting is performed simultaneously with settlement generationCompensation grouting may be:

ConcurrentObservational

Kummerer (2003)Monitoring is a key element of settlement control/compensation

Types of groutingCompaction grouting

Injection of stiff high viscosity grout

Harris (2001)

Fracture grouting Injection of low viscosity grout

at pressures that cause fracturing

Intrusion grouting Injection of a fluid grout with a

high solids content. Solids remain near point of injection but limited fracturing

Fracture groutingTAM (sleeve) grouting

Harris (2001)

Compensation grouting

Harris (2001)

The conceptual aim is to compensate the ground movements in the same zones where subsidence is generated

This principle is not consistent with the need to leave anexclusion zone near the tunnel face

There are practical difficulties to perform true compensation grouting when THM excavation advances rapidly


Compaction grouting Bolton Hill Tunnels, Baltimore (Baker et al, 1983) Minneapolis tunnel (Cording et al., 1989) By the 1990’s compensation using compaction grouting well

established in the US (Littlejohn, 2003)

Fracture grouting Essen in 1986 (Chambosse & Osterbein, 2001) Vienna metro (Pototschnik, 1992) Other tunnels in Germany & Austria (e.g. Raabe, 1989) First used in UK in Waterloo station, 1992 (Mair & Hight, 1994) Extensive use in Jubilee extension line, London (well

documented; Burland, Standing & Jardine eds.) Used extensively: Lisbon, Porto, Madrid, Barcelona, Antwerp and

many others (also sometimes used in the US)

The term compensation grouting Apparently coined by D.W. Hight (GCG) (Mair, 1994)

Compensation grouting: a bit of history

Compaction grouting Better control of grout

extension More robust with respect to

implementation parameters Repeat grouting requires

redrilling Higher injection pressures Creates a smaller region of

pore pressure increase Dominant in the US

Compaction grouting vs. Fracture grouting

Fracture grouting Little control of fracture

extension and direction Multiple injection is

straightforward (TAM grouting)

Lower efficiency? Lower injection pressures Creates a larger region of

pore pressure increase Dominant in the Europe


Execution phases Drilling and installation of TAMs

Preliminaty grouting Pre-treatment grouting (immediately after installing TAMs) Conditioning grouting (compress the ground, restore

decompression caused by drilling and installation, leave the ground ready for lifting)

Concurrent grouting (during tunnel drilling/excavation)

Corrective grouting. After tunnel drilling/excavation


Treasury Building (Jubilee Line Extension)



Viggiani and Standing (2001)Plan view



01020304050distance from corner of ICE

Treasury

made ground

London Clay

shaf

t 3/2G

reat

Geo

rge

St.

eastbound

westbound

array of TAMs -15.5 m (89.5 m PD)In

stitu

tion

of C

ivil

Eng

inee

rs(IC

E)

-23 m(82 m PD)

-32 m(73 m PD)

Terrace Gravel

0.00

-7.00

-11.0

1 23

45

6789

101112

13

14

1516

1718

19

123

4

56

7

8 9 10 11 12 13

141516

171819

2021222324

2526272829

30

31

32

33

34353637

ICE

shaft 3/2

TREASURY1

2

3

4

5

6

7 8 9

10

11

12

13

14

15

16

17

18 1920 21

2223

2425

262728

2930

3132

3334

3536

373839404142

4344

45

46474849

5051

525354

555657

5859

60

61

62

63

64

65

66

67

68

69

70

71

72


Cross section

TAM array



2 x 5m dia. Tunnels excavated with open-face shield


Treasury

made ground

London Clay

shaf

t 3/2G

reat

Geo

rge

St.

eastbound

westbound

array of TAMs -15.5 m (89.5 m PD)

Inst

itutio

n of

Civ

il E

ngin

eers

(ICE)

-23 m(82 m PD)

-32 m(73 m PD)

Terrace Gravel

0.00

-7.00

-11.0

eastboundwestbound TREASURY

ICE


Location of levelling points



Treasury

made ground

London Clay

shaf

t 3/2G

reat

Geo

rge

St.

eastbound

westbound

array of TAMs -15.5 m (89.5 m PD)

Inst

itutio

n of

Civ

il E

ngin

eers

(ICE)

-23 m(82 m PD)

-32 m(73 m PD)

Terrace Gravel

0.00

-7.00

-11.0

eastboundwestbound TREASURY

ICE

Viggiani, 2001

Contours of grouting intensity (l/m2)

Observational grouting performed after drilling West tunnel



GEF = 0.3-0.5 (0.7 in the final stage)

100 80 60 40 20 0distance along façade (m)

-30

-20

-10

0

verti

cal d

ispl

acem

ent (

mm

)



-30

-20

-10

0

verti

cal d

ispl

acem

ent (

mm

)


tunnel face advance

tunnel face advance

westbound - without compensation grouting

eastbound - with compensation grouting

after westbound observational grouting

long term



Settlements

West tunnelNo compensation

grouting

West tunnelCorrective grouting

East tunnelWith compensation

grouting

Long term settlements


Transitory movements more severe

wellswells

Kummerer at al. (2003)

Antwerp Central Station

GEF = Grout Efficiency Factor GEF = Volume of ground heave/ volume of grout injected

Typical values for fracture grouting in stiff clays: 0,3 – 0,5; in granular soils can be as low as 0.05 - 0,1

In soft clays with low OCRs, GEF can be negative

GEF usually increases as grouting progresses


Grouting generates pore pressures especially in soft clays Dissipation of pore pressures will cause settlement and counteract

compensation grouting heave

Use of compensation grouting in soft clays

Komiya et al. (2001)


Compensation grouting trial in Singapore marine clay (Shirlaw et al., 1999)

Use of compensation grouting in soft clays


2

max 32 lDs Vi


Juan Valera road


Juan Valera road

W.T.

W.T.

Silt with sand and gravel

Gravel and coarse sand

Silt with sand and gravel

Grouting wellGrouting well

Grouting boreholes

TUNNEL


Rodio (2005)


Juan Valera road

-3

-2.5

-2

-1.5

-1

-0.5

0

0.5

1

10/6/2003 10/31/2003 11/25/2003 12/20/2003 1/14/2004 2/8/2004 3/4/2004 3/29/2004 4/23/2004

Time

Point HT1 (13.2m to the northof tunnel axis)

Point HT2 (3.2m to the northof tunnel axis)

Point HT3 (16.1m to the southof tunnel axis)

Vert

ical

dis

plac

emen

t [m

m]

Pas

sage

of E

PB


Juan Valera street

0

5

10

15

20

25

30

-10 -5 0 5 10 15 20Vertical displacement [mm]

Dep

th [m

]

At 9.1 m from the centrelineOn the tunnel centreline

Settlements


Existing Napoli-Milano rail link on masonry viaduct

Three strings of water level settlement gauges

17.9m10.6m

Tunnel

9.1m

Silt and clay

Made Ground

Sand Gravel

SandSand

GravelGravel

Made Ground

As-built extent of treatment zone

Bologna viaduct and soil profile


Acknowledgments to R.J. Mair

Viaduct 112 m long, 11m wide

Bologna viaductCompensation grouting

60.157.7

Temporary pit

59.4

Existing Napoli-Milano rail link on masonry viaduct

Treatment zone

Two layers of curved TAMs

Tunnel 1 Tunnel 2Scale

0 10m

42.03.0m4.4m

1.5m

Pigorini et al (2009)

Cross section


Vertical control 1m, horizontal control 0.5m for a 60 m long borehole

Foundations of masonry viaduct

Tunnel 1Tunnel 2

TAMs

Drill rig positions0m 100m

ScalePigorini et al, 2009Pigorini et al (2009)

TAMs array


Directional drilling


Grouting


Distribution of grouting volumes


0

40

80

120

28/06/05 30/06/05 02/07/05 04/07/05 06/07/05

Time

Gro

ut v

olum

e (m

3 )

0.0%

0.4%

0.8%

1.2%

Gro

ut (%

of e

xcav

ated

vol

)Cumulative Grout Vol

% Grout vol/ Excavated vol

3300

3350

3400

3450

3500

28/06/05 30/06/05 02/07/05 04/07/05 06/07/05

Cha

inag

e (m

)Cumulative grout vol% Grout vol/ Excavated vol

Gro

ut v

olum

e (m

3 )C

hain

age

(m)

Gro

ut (%

of e

xcav

ated

vol

)

Time

0

120

80

40

28/6/05 30/6/05 02/7/0504/7/05

06/7/05

28/6/05 30/6/05 02/7/05 04/7/05 06/7/05

0.0%

0.4%

0.8%

1.2%

3500

3400

3300

Viaduct + 4m border

Volume loss 0.2%


Grout volume and progress of TBM1


GEF=0.33-0.50

-18-14-10-6-22

3310333033503370339034103430Chainage (m)

Settl

emen

t (m

m)

PredictedVL=0.2%

-18-14-10-6-22

3310333033503370339034103430Chainage (m)

Settl

emen

t (m

m)

West

East

PredictedVL=0.2%

0

50

100

Gro

ut

(l/m

2 )

Differential settlement limits between piers

1:3000 Grouting trigger1:1000 Contractual limit


No grouting VL=0.2%

Evolución de asientos


Barcelona Metro: Line 9 Piled buildings

Ferran Soldevila street


TUNNEL

Barcelona Metro: Line 9 Piled buildings


Conditioning grouting


Westminster station


34m

Inyecciones de compensación Westminster station

Buried prop


Westminster station


39 m deep excavation 2 x 5 m dia. tunnels to be enlarged to 7 m dia.

TAMs array

Westminster stationCompensation grouting

Big Ben

Westminster station


H = 55m

HΔ

= Tilt

Inyecciones de compensación Westminster station

Clock Tower tilt

Δ= Tilt H (H=55m)

Compensation grouting Westminster station

Clock Tower tilt

Final remarks Control of ground movements is an absolute requirement when tunnelling in

urban areas There is an enhanced sensibility of public opinion concerning these

issues The most effective measure for the control of ground movements is the

selection of an adequate construction procedure and a good control of the works

Screen (curtain) walls are an efficient way of ground movement control when the tunnels are not excavated below buildings

Compensation grouting is an efficient way of ground movement control when the tunnels are excavated below buildings There are however uncertainties over the behaviour mechanisms and

control methods Whenever possible, acting directly on the structure leads to a better control

when correcting the effect of ground movements Often the control measured also generate additional ground movements

It is not recommended, therefore, to try to reduce ground movements to negligible values

nz course tunnelling - amazon web services general remarks any tunnelling activity causes ground...

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