4) keynote 1 by prof yong ky_young people session

8/19/2019 4) Keynote 1 by Prof Yong KY_Young People Session

1/25

6/6/

Welcome

to

the

National

Universit of Sin a ore NUS

Kent Ridge Campus + University Town

Bukit Timah Campus

Duke‐NUS @ Outram Campus

Yale‐NUS College

K Y YONG, National University of Singapore

Kent Ridge Campus

Kent RidgeCampus

University TownBukit TimahCampus

OutramCampus

GFA: 250,000m2

Land: 19 ha

GFA: 38,700 m2

Land: 5.3 ha

2 ,Land: 3 ha

,Land: 141 ha


2/25

6/6/

-

Fusionopolis

National

University

Hospital

3

Singapore

Science ParksMap courtesy ofJTC Corporation

Kent Ridge CampusKent Ridge Campus


3/25

6/6/

National University of Singapore

Planning, Design and

Construction of Underground

‐ some challenges ‐

K Y Yong, National University of Singapore

Paul Fok, Land Transport Authority, Singapore

Presented

at

the

World

Tunnel

Congress

2012


4/25

6/6/

Planning, Design and Construction of

Underground MRT System in Singapore

• Overview of

Singapore

Transport

System

• Site Investigation‐ Adequacy and reliability of SI

‐ Geotechnical Interpretative Baseline Report

‐ Detection of pile capacity

• Deeper excavation for MRT Stations

• Challenges in urban tunnel construction‐ ace pressures

‐ Tunnel near critical structures

‐

Tunnels

in

settling

ground‐ Durability of tunnel structure

• Conclusions

MRT Network

in

Singapore

Now 176 km of rail 122 stations; by 2020, 280km rail and 183 Stations


5/25

6/6/

Major Underground Road Tunnels

CTE: North Tunnel: 0.7 km;

KPE: Total tunnel length:

9km; Opened 26 Oct 2007

Woodsville Interchange:

Total tunnel length: 0.69km;

Opened 28 Jan 2012

North South Expressway

Tunnel and Semi Tunnel :

12.3 km to be completed

around 2020

South Tunnel: 1.7 km; Opened:

21 Sep 1991

Fort Canning Tunnel:

0.35 km; Opened 16 Jan

2007

and 20 Sep 2008

MCE Tunnel : 3.5km to be

opened at end 2013

Singapore UndergroundRoad System: underground

road tunnels

GEOLOGY OF SINGAPORE

Old AlluviumSedimentary

Formation

Bukit Timah

Granite

Kallang

Formation


6/25

6/6/

GEOLOGY ALONG THE MRT NORTH‐EAST LINE

Site Investigation: field

and laboratory works

Site Investigation Report

Geotechnical Factual

Report (GFR)

Geotechnical

Interpretative

Report (GIR)

Contains the factual data from site

investigation & laboratory tests

Interpreted ground conditions for design,

e.g. design sections, design parameters

Geotechnical

Interpretative

Baseline Report

(GIBR)

Nature, form, composition, properties

and structure of the ground and

groundwater, artificial obstructions

From DTL


7/25

6/6/

Challenges in Site Investigation

• To have more boreholes – practical

problems

• To carry out geophysical survey

Prediction of

soil

‐rock

interface

from

boreholes

Tunnel Alignment


8/25

6/6/

Longitudinal

Soil Profile

FILL

F1 : FLUVIAL SAND

E : PEAT/ORGANIC CLAY

M : MARINE CLAY

G (I)

G (II)

G (III)

G (IV)

G (V)

G (VI)

F2 : FLUVIAL CLAY

Tunnels to 6th AvenueTKK Stn

C918

Limit of Contract

Hwa Chong Institution

C918

Limit of ContractC917

Tunnels to Botanic Garden

- 5 - 4

A

- 4 - 2 - 1 0

1 7

1 4 6

0 1 8

0 1 9

2 1 4 7

0 1 5

2 1 5 4

2 3 6 6

3 6 5

K 0 1 3

D T 2 0 2 0

D T 2 1 4 9

D T 2 0 2 1

T 2 1 5 1

0 1 4

2 1 5 2

2 1 5 3

3 6 5 A

T 2 7 0 8

2 3 6 7

D T 2 1 4 8

T 2 1 5 0

D T 2 3 6 8 A

D T 2 3 6 8

D T 2 1 4 9

T 2 3 7 1

a r r e r

l y o v e r

0 2 4

1 4 5

C919

2 3 0

4 2 4

4 2 3

Cut & Cover 130-

120-

B H B

B H B

B H B

B H

B H B

D T 2

D T 2

D T 2

D T

D T

B K

D T

D T

D T B D B

K D D

T

D T

D D T D D

C C 4

D T 2

C C 4

C C 4

C C 4

G III OR BETTERROCK

G VIG VI

E G VI

G V & G IV

G VI

G V & G IV

F1 & F2

F1 & F2

FILL

1550-

80-

100-

90-

110-

70-

60-

G III OR BETTER

ROCK

To City To Bukit Panjang

15

Boreholes and probes concentrated onERSS and Station Box


9/25

6/6/

Bukit Timah Granite

Geological Conditions at T4

Kallang Formation

Bukit Timah Granite

Bukit Timah Granite

Bukit Timah Granite

Ground formation

in

cross

section

It is also important to plot geotechnical profile against

the section of the station box or tunnelling

Cross section without round formation

Blk 60 Blk 67

2 1 . 1

u n

n o w n

3.63

m

2 0 . 6

u n k n o w n

3.29m

2 1 . 0

5.34m


10/25

6/6/

Borehole BH

Cross Section with Geotechnical Profile

2 5 m

a i n b l d g . p i l e s )

OA

Fill

M

2 2 m (

l i f t - c o r e

p i l e s )

+103.2m

+101.6mFill

+99mM

+88.6m

O(D) N-SPT~20

+86.1m

O(C) N-SPT~49

G002

u

n k n o w n (

4.4m

7m4.6m

5m +80.1m

O(B) N-SPT~89

O(A) N-SPT~100

Geophysical Survey

• Commonly used methods

Seismic refraction

Seismic reflection

Surface wave method

‐

20


11/25

6/6/

Geophysical Survey

• Methods commonly used for soil / rock

interface identification

• Results are

‐ indirect interpretation of ground condition

‐ influenced by many factors, e.g. utilities,

traffic noise

Soil / Rock

Interface

– Accuracy

?

Interpreted Profile of Surface Wave Velocity

Interpreted Rock Profile


12/25

6/6/

Soil / Rock

Interface

– Accuracy

?

ABH1

8

ABH2

1

ABH2

6 FILLF1

GV &

GVI

GIII &

II

FILLF1

GV &

GVI

GII & GIGIII, GII &

G1

FILLF2EF1F2F1

GVI &

GV

GII

HDB

Tunnelling

induced ground

settlement

impacts footing

Geotechnical

Challenges

4 Storey

Block

Spread Footing

Existing

Micropiles

150mm, 200mm

Head Room

Clearance height ~

6.5m

110m

100m

3

m

RL 107.58

GVI

Section A‐A

90m

.

GIII

Piles obstruction

to TBM tunnelling

Mixed face

tunnelling


13/25

6/6/

Station T11 – Grouting Works for Steel Pile Cutting

ST/0099 DT/2132

103.5

98.5 IL

103.5

84.

082.

4

Steel Piles

H356x368Steel Piles

H254x254

97.

8

86.

7

DTL

tunnels

Tanalised

Piles

TBM

directionSteel Piles to be cut from TBM face

5m

Steel Piles

H254x254

Steel Piles spacing

unknown

Jet Grout

June 6, 2013 Page 25IBA Briefing #2

.

1Water-sealant Grouting 74.

1Toe Level Unknown

Cement Grout (microfine)

18m

GV 5m

Detection of Pile Depth – Accuracy?DTL3 Example – Ground Penetration Radar Survey


14/25

6/6/

Detection of Pile Depth – Accuracy?

Estimated Pile Penetration: 21~22m (or)

26~27 m

Challenges in

SI

and

detection

of

piles

• More efficient and accurate methods are

required to determine

rock levels

depth of piles

construction in urban areas


15/25

6/6/

Subway

Deeper Excavation – Bencoolen Station

SMU

BENCOOLENSTREET

Depth of s tation 43.2m

Ground treatment

to

control

settlement

Clay without Ground

Treatment

Deep Excavations in Sof t Clay

with Ground Treatment

Ground

Treatment


16/25

6/6/

90

95

100

105

90

95

100

105

70

75

80

85

E l e v a t i o n ( m R L )

70

75

80

85

E l e v a t i o n ( m R L )

DSM

55

60

65

-20 0 20 40 60 80 100

Displacement (mm )

Design-East Bound IW5TA09

55

60

65

-20020406080100

Displacement (mm )

Design-West Bound IW5TA08

March 2011

C485

TBM for

Downtown

Line

(DTL)

• DTL1: 3 EPBMs

• DTL2: 10 EPBMs + 9 Slurry TBMs

• DTL3: 19 TBMs

EPBM (C902) Slurry TBM (C915) EPBM (C917)


17/25

6/6/

Volume losses for EPBM in Jurong

(Sedimentary) Formation

Blow‐Out


18/25

6/6/

Tunneling in Mixed Face Conditions

Tunnel Alignment

Tunneling under a building

North Bound

Tunnel

South Bound

Tunnel


19/25

6/6/

Typical instrumentation array prior to

tunnel crossing beneath critical structures

1 m

surface settlement

measurementassumed lateral

ground settlement

measurement

extensometer

inclinometer

roun e orma on

Phase VA

1974-1977

Phase VI

1979-1985

Original Shoreline

1950s Reclamation

Package C

Tunnels

in

settling

ground

Phase VII

1979-1985

Phase VB

1974-1977

ase

1972-1994

1964 Shoreline

N

Area Stu died f or

Consolidation Settlement Analysis

• Sand-fill 5m – 20m, typically 10m

• Marine Clay, 10m-35m thick , still conso lidating.

• Consol idation time expected 60-80 years


20/25

6/6/

100100

9090

8080

Geological Profile

7070

6060

5050

4040

Station T21 C&C Tunnel

100100

9090

8080

7070

Station T22C&C Tunnel

5050

6060

Shanghai Metro No. 1 Line

.1995-2007 settlement development with time at different sections in Shanghai Metro No.1 Line

-150

-100

-50

0

S

e t t l e m e n t / m

-300

-250

-200

1 9 9 5 年 1 2 月

1 9 9 6 年 3 月

1 9 9 6 年 6 月

1 9 9 6 年 9 月

1 9 9 6 年 1 2 月

1 9 9 7 年 3 月

1 9 9 7 年 6 月

1 9 9 7 年 9 月

1 9 9 7 年 1 2 月

1 9 9 8 年 3 月

1 9 9 8 年 6 月

1 9 9 8 年 9 月

1 9 9 8 年 1 2 月

1 9 9 9 年 3 月

1 9 9 9 年 6 月

1 9 9 9 年 9 月

1 9 9 9 年 1 2 月

2 0 0 0 年 3 月

2 0 0 0 年 6 月

2 0 0 0 年 9 月

2 0 0 0 年 1 2 月

2 0 0 1 年 3 月

2 0 0 1 年 6 月

2 0 0 1 年 9 月

2 0 0 1 年 1 2 月

2 0 0 2 年 3 月

2 0 0 2 年 6 月

2 0 0 2 年 9 月

2 0 0 2 年 1 2 月

2 0 0 3 年 3 月

2 0 0 3 年 6 月

2 0 0 3 年 9 月

2 0 0 3 年 1 2 月

2 0 0 4 年 3 月

2 0 0 4 年 6 月

2 0 0 4 年 9 月

2 0 0 4 年 1 2 月

2 0 0 5 年 3 月

2 0 0 5 年 6 月

2 0 0 5 年 9 月

2 0 0 5 年 1 2 月

2 0 0 6 年 3 月

2 0 0 6 年 6 月

2 0 0 6 年 9 月

2 0 0 6 年 1 2 月

2 0 0 7 年 3 月

2 0 0 7 年 6 月

Time


21/25

6/6/

Durability of tunnel structure

Typical durability

problems in a live tunnel

structure built in earlier

MRT works

Better quality of tunnelstructure in recent MRT

works in Circle Line

SFRC Segments

for

DTL3

– 2350m

of

bored

tunnel

• Elimination of risk of steel bar corrosion

• Elimination of concrete spalling risk

• ore ura e segmen w m n ma n enance

effort

Upper track in Kallang;

Lower track in OA, short

len th in Kallan ~650m

Both tracks in Old

Allu vium ~1350m

Both tracks

in Kallang

~350m

Cross Over

at Jln Besar

Tunnel Escape

Shaft

Sungei Road

Station

Kalang Bahru

StationJalan Besar

Station

Tunnel Escape

Shaft


22/25

6/6/

Challenges in Urban Tunnel

Construction

• accuracy of SI and pile detection

• ground treatment to control settlement

• face pressures in mixed soils

• tunnels near or below structure

• tunnels in settling ground

• Durability of

tunnel

structures

Grand Challenge: To Plan, Design and Develop a

Sustainable and Liveable City for 6.9m People

Intr EconomicDevelopment

Housing Water ConclusionPort JurongIsland

UAF NRF

3rd April2007 44


23/25

6/6/

Land is the Most Critical Constraint for the Development of Singapore Total Surface Area


24/25

6/6/

The Deep Tunnel Sewerage

System (DTSS)

Crowded underground

MRT

lines

Existing Tunnels

Top tunnel in

Marine Clay

Bottom tunnel in

OA

Future Tunnels

Existing

Piles /

Barrettes

Transfer Beams

and Barrettes for

Underpinning


25/25

6/6/

INNOVATION FOR

A CROWDEDUNDERGROUND

THANK YOU

4) keynote 1 by prof yong ky_young people session

Documents