SysEng (S) Pte Ltd
Wisescan Engineering
Pte Ltd
Siber Hegner South East
Asia Pte Ltd
GeoEng Consultants
Deploying Remote Wire-less
Automatic Tunnel Monitoring System
to reduce the risks of uncertainties
By Dr G H Tan
This presentation describes the Automatic
Tunnel Monitoring System used for the
Construction of Newton Life Church
The consortium comprises of
SysEng (System Designer for the Automatic
Wire-less and Internet Monitoring System)
Siber Hagner (Leica Geosystem Instrument
Integrator)
Wisescan Engineering (Tunnel Surveyor)
GeoEng (Geotechnical Specialist)
• Started in 1994
• Specializes in Test & Measurement
• Signal Analysis and Digital Signal
Processing Techniques Wireless Data
Acquisition Systems
• Structural Instrumentation for Buildings,
Tunnels, Highway bridges
• Vibration and Acoustic Measurement
Systems.
• Machine Vision Inspection Systems
SysEng (S) Pte Ltd
Wisescan Engineering
Services Pte Ltd • Founded in 1992 and awarded ISO 9002 1997
• General Engineering survey
• MRT Tunneling Survey
• Tunnel Deformation and Monitoring Survey
• Ground Settlement Movement Study Survey
• Hydrographic Survey
• Cable and Gas pipe as-built survey and
production of drawing in GIS format
Siber Hagner South East
Asia Pte Ltd• Regional representative for Leica Geosystems
covering Malaysia and Singapore
• Support Leica Geosystems Software with local
customization
• 1st Tunnel Monitoring System carried out for
Bugis Junction in Singapore 10 years ago
GeoEng Consultants
Specialist Civil and Geotechnical
Consulting Engineers
•Temporary Retaining Systems
•Soil Improvement
•Underground Support Systems
•Foundation Systems
•Underpinning of Buildings
•Basement Design
•Trenchless Technology
Structural Health Monitoring Systems
• Republic Plaza Building (280 m) since 1995
• OUB Building (280 m)
• Toa Payoh 25 storey HDB Building
• Tuas 2nd Link Bridge since 1996
• Kranji Expressway LTA C3623
• North East Tower in Hong Kong (420 m)
• Changi Airport Car Park Terminal 2 LTA C504
• Pasir Panjang Semi-Expressway C3223 since
2002
• Bukit Timah Expressway C3222 since 2002
Automatic Tunnel Monitoring Systems
• Changi Airport Runway 1 Monitoring LTA
C5342
• Circle Line LTA C825 North & South Bound
• SMU site
• Church Street Building
• Circle Line LTA C825 East & West Bound
• Harbor Front LTA C859
• Newton Life Church
• National Library Board
• Deep Tunnel Sewage PUB T06
• Monitors adjacent buildings when an old
building is being tore down and rebuild to a
higher building
• Monitor piling and soil movements do not
affect existing structures
• Population will grow in ASEAN, China, India
• Cities will increase in densities
• Demand for transportation in cities will rise
with Highways and Tunnels
• Infra structures have to be upgraded
Monitoring to minimize risks
Typical Challenges face
by Construction
Industry as reported in
Straits Times, showing
Damages & Disruptions
to Infrastructures and
Assets
Automatic Tunnel Monitoring
Developed for Infra structure and
Asset Protection• Longer underground networks and crossing
each other
• High density buildings near underground
stations due to popularity and convenience
• Other underground networks like Deep
Tunnel Sewage, Power Utilities, Water, Gas,
Telecommunication
• Expensive to repair underground if damage
Consequences of late awareness
in Structure & Soil movements
• Loss of lives (Like Hotel New World)
• Unwanted publicity in Newspapers
• Delays in completion of projects causing
cash flow problems
• Show poor performance of company
• Legal and Financial consequences for
damaging assets
• Losing future potential businesses
To achieve a robust &
reliable monitoring
system, the technologies
deployed must be reliable
and have local technical
support to ensure high
system up time for the
clients
What is eMonitoring ?
• Wire-less for data communication by riding
on the open public mobile phone infra-
structure to give REAL TIME ALERT to
multiple users
• Internet monitoring for automatic data
collection and monitoring at a central server
• The customer to receive the data via
the Internet making the information
available to more users .. faster
Outdoor Inspection
Monitoring
Street Light
Monitoring
Tunnel Monitoring
Water Level
Monitoring
Geotechnical
Monitoring
The RTU takes a
photo of floodgate
when it opens or
close.Internet
Users
There are diff. type of
devices to access the
application services through
diff. protocol.
Web
Server
GPRS/
GSM
Gateway
Supervisory
Monitoring
Overview of eMs Application
The Leica’s instrument
scan the reading by
prism installed at
tunnel and the RTU will
send the reading back
to eMs Server.
The street light
located at
crowded area,
like shopping
centre, school
and tourist
spot become
important and
crucial at night.
When the light bulb spoilt, the
RTU control unit in the street
lights will alert the users and
report to server.
The RTU will have
the function of taking
photos, GPR, Times
Stamps, and memory
for the storage
information. This
information can be
sent to server
through wireless
network. It is kind of
outdoors surveillance
systems.
The RTU will send the
information given by
the sensors installed
inside the bridge to the
control centre.
eMonitoring System applied to
Tunnel Monitoring SystemMobile
Alert
Devices
for
Urgent
Information
Instrument
inside in
Tunnel
Email &
ftp site
download
Tunnel Monitoring
System featured in
Business Times
13th March 2003
by Infocomm
Development
Authority of
Singapore
Proven Audited
Performance with
System Up-Time of
99.5 %by IDA
Locally
Developed to
suit local
conditions
1.Automatic Measurement and Data capturing
2.Wire-less technologies for data
communications from remote sites
3.Internet web-enable to reach a larger user
base and ease information flow
4.SMS alert to leverage in Mobile phone
networks
5.Lightning and Surge protection
6.Outdoor tropical climate protection design
for sensitive electronics
7.Deploy system which can be supported and
service locally
• Automatic Target
Recognition system
• Glass prism as reflectors
• Range 5 to 1000 m
• Distance Accuracy +/-
1.0mm + 1ppm
• Angular 0.5 arc second
• 60 systems installed in
Singapore
• Highly reliable for
continuous use in Tunnels
Leica High Precision Instrument TCA2003
1.Automatic Measurement and Data capturing
2.Wire-less technologies for data
communications from remote sites
3.Internet web-enable to reach a larger user
base and ease information flow
4.SMS alert to leverage in Mobile phone
networks
5.Lightning and Surge protection
6.Outdoor tropical climate protection design
for sensitive electronics
7.Deploy system which can be supported and
service locally
Reliability of communicationRemote User
12
34
5 6
UserService
Provider
1 2
For the signal to flow through from the Remote site to
the end user, the wired signal has to pass 6
connections. If any connection is down, the
communication is cut off.
Reliability of this system is 1 = 0.015
26
Reliability of the wire-less system is 1 = 0.25
22
An improvement of 16.6 times !
Remote
Wire-less communication is reliable if the setup
is done correctly
The technologies available are :-
• GSM data (Switch Circuit Technology)
• GPRS data (Packet Transmission)
• 2.4 GHz Spread Spectrum
• 802.11g WiFi
• Point to Point radio modem
GSM Signal Strength Level
Challenge of developed New Data Transmission Technique
within 24 hours to overcome signal strength drop out during
Peak periods (~ train move @ 5 minutes intervals !)
GSM RF signal
strength site
survey to ensure
signal level is
reliable for data
transmission.
The Signal
strength is
captured and
logged over 2
weeks to select
suitable antennas
and alignment
1.Automatic Measurement and Data capturing
2.Wire-less technologies for data
communications from remote sites
3.Internet web-enable to reach a larger user
base and ease information flow
4.SMS alert to leverage in Mobile phone
networks
5.Lightning and Surge protection
6.Outdoor tropical climate protection design
for sensitive electronics
7.Deploy system which can be supported and
service locally
Automatic Tunnel Monitoring
Email &
ftp site
download
Instrument
inside in
Tunnel
Mobile
Alert
Devices
for
Urgent
Information
Most people uses the
Internet for receiving
email information
according to this
survey. The
eMonitoring system
uses the most
popular method to
deliver Tunnel
Deformation
information
•Data from site to server using GSM 5 mins
•Processing measured data at server 1 min
•email out to customers within 1 min
•SMS alerts received by users within 1 min
even for cross Telcos
Hence worst case is 8 minutes from site to end
users consistently for every cycle 24 hours a
day. While a manual system with the data is
retrieved manually using wire-less method and
then manually upload to a FTP site
Typical system respond times
1.Automatic Measurement and Data capturing
2.Wire-less technologies for data
communications from remote sites
3.Internet web-enable to reach a larger user
base and ease information flow
4.SMS alert to leverage in Mobile phone
networks
5.Lightning and Surge protection
6.Outdoor tropical climate protection design
for sensitive electronics
7.Deploy system which can be supported and
service locally
Misinformation & Delay of a Manual
Alert System
Monitoring Worker
Monitoring Sub-Contractor
Main Contractor
Excavation Worker
0.9
0.9 0.9
0.9
Misinformation = 0.94 = 0.65 !
Delay (mins) = 30 + 30 + 30 + 30 = 2 hours
Consultants
Action
Automated Wire-less Alert System
Automated Wire-less
Monitoring System
Monitoring Boss
Main Contractor
Consultants
1.0
1.0
1.0
Misinformation = 1.0 (Manual of 0.65)
Delay (min) = 1.0 (Manual of 120.)
Smart Alert Algorithms
• Differentiate real alerts from glitches
based upon field knowledge rather
than based upon threshold limits
• Need to understand Structural and
Geotechnical behaviors to eliminate
false alerts
• False alerts makes Alert system
unreliable
Alert System
must Guarantee
a 1 min SMS
delivery time to
clients using
different Telcos.
Wrong
technique used
causes SMS
delay for hours
1.Automatic Measurement and Data capturing
2.Wire-less technologies for data
communications from remote sites
3.Internet web-enable to reach a larger user
base and ease information flow
4.SMS alert to leverage in Mobile phone
networks
5.Lightning and Surge protection
6.Outdoor tropical climate protection design
for sensitive electronics
7.Deploy system which can be supported and
service locally
Use known standards for Lightning
and Environmental Protection
• Lighting Protection CP33
• Environmental Protection IP65
A Proper Protection System is not
just about buying and installing
the correct part numbers
according to catalogue pictures
• Wiring the lightning discharge path
• Isolating the signal, power and
mains earth
• Mains discharge path is different
from signal noise discharge path
1.Automatic Measurement and Data capturing
2.Wire-less technologies for data
communications from remote sites
3.Internet web-enable to reach a larger user
base and ease information flow
4.SMS alert to leverage in Mobile phone
networks
5.Lightning and Surge protection
6.Outdoor tropical climate protection design
for sensitive electronics
7.Deploy system which can be supported and
service locally
Deploy system which are
supportable and
serviceable
Not just the Best Parts or
Best Brand for the whole
system
Typical challenges in Outdoor
systems
• Ensuring Quality of data
• System works well for first 6 months
• Supporting companies must have
technically manpower to troubleshoot
complex system
• Supporting company must have multi-skilled
staff
• Manufacturer usually do not have local
tropical climatic experiences
The infamous
Dr Frankenstein use
the Best of Everything
to create a Monster who is
made from parts from
different suppliers. A system
has to consider the working
strength and weakness of
all parts
Blue Tooth ?
Pocket PC ?
IEEE802.11g ?
GPRS ?
WAP ?
WiFi ?
3G ?
It is about Deploying Appropriate
Technologies which are stable, reliable
and locally supportable for changes to
suit customer applications
Important from Business View
• What can you add value to your
customers ?
• What you can do for them ?
• Don’t tell the customers what you
technologies you have
• Help customer solve his problem
• Customer don’t buy technology but
solutions
• LTA code of practice allows less than 15mm
movements along the segments
• Tunnel distortion allowable is 1/2000
• Continuously monitors the prisms every 8
hours per day for 7 days a week
• Reliable System up time with penalty
imposed for loss of data
• Real time measurement and immediate data
transmission of results
• Immediate alerts if the movement exceeds
70% of allowable movement
Total Instrumentation Plan: Around the Excavation site
SM16
SM17
SM18 SM19 SM20TM2 CM2
PZ5I5 WS5
SM21 SM22 SM23
CM1
TM1
SM24
SM25PZ6I6
WS6 SM26
SM1
WS1I1PZ1
SM2
SM3WS2I2*PZ2
SM4
SM5
SM6SM7SM8
*PZ3I3
WS3SM9SM10
SM29SM28WS7
SM11
VS3CM3TM3
SM27
WS4PZ4SM12
SM13 I4SM14SM15
Inclinometer
LEGEND :
Water Standpipe
Pneumatic Piezometer
Settlement Marker
Tiltmeter
Crackmeter
Automatic Trainway Monitoring System
Vibration Sensor
Manual Survey
Automatic Tunnel Monitoring
System Operation to achieve
requirements
• Initial setup
• Data Retrieval
• Manual System as a backup support
• Data Comparison
• Manual readings are carried out to record
initial readings for glass prisms
• Once base readings are obtained & set, the
automatic system is commissioned
• Instrument is pre-programmed to take prism
readings
• The captured data is automatically transmitted
from site to office via wire-less means
• Leica APSWin performs the analysis and data
stored
Initial setup
Data Retrieval
• Data retrieved is automatically done 3 times
per day at every 8 hours cycle
• Received prism x,y,z data are automatically
analyzed into tunnel deformation information
• Information is automatically email to the LTA,
clients and consultants
• Results are automatically backup in server
as well as upload to a FTP site
• The results are produced as numerical and
graphical plots
Data Retrieval Consistency
Actual Data
Retrieval
timings
showing the
time and file
size received at
the server end
Manual system as a backup
support
• During operation of the Automatic Tunnel
Monitoring system, manual survey is still
being carried out but less often for system
verification purposes
• Readings are captured by another TCA2003
unit for comparison purposes
• Served as a backup and independent audit
from the auto system
Comparison between Automatic
and Manual Readings for one cycle
-10
-8
-6
-4
-2
0
2
4
6
8
10
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
Auto
Manual
Lateral Movement for Track Prisms
X (+ ve = movement towards development site)
X
Deviation
in mm
Ring segment number
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