Landslide ,
System Brochure
Applications
System Integration
Example
I
Example
II
Example
III
Example
IV
Installation
Pre-warning for debris, Rock-fall,
Land-Slide
position
of gate
for
Flash Flood
for
Water Resource
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Innovative Instrumentations for |
Landslide
and Debris flow monitoring |
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There appear geological disasters including
collapse, slide, and debris flow. In addition to natural
slopes, the excavated slopes referred to as cut slopes
e.g. roadway slopes resulting from roadway excavations,
which seriously result in a threat to public safety. In
order to react to the considered phenomenon, TWSI offers
a series of cost effective products for displacement
measurement and introduces the StormPanel to optimize
the community-based early warning systems and provide
other new solutions with Smart Repeater for durable and
reliable environmental monitoring. |
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◎ Automatic, Digital
The system adopts the auto-monitoring and event trigger
method. Using TWSI Digital Wire Extensometer for
monitoring landslides ensures an evolutional up-grate to
conventional analog transducer. When the variations
occur, the signal of per 1 mm displacement triggers the
transmitter in pulse mode, at the same time, the digital
data of highly precise position in absolute format can
be read in serial mode. If no variations occur,
transducer and transmitter consumes very low power and
will be awakened by RTC and then transmit periodically
to refresh the status. |
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◎ Real-time, Trigger alarm, Wireless, Flexible
The TWSI Digital Extensometer detects events and
triggers a transmitter which in turn sends instantaneous
messages with RF signal for data acquisition and further
alerts. The monitoring data are received and displayed
on either StormPanel or SCADA systems. The transmitters
are battery operated with a battery life of 2-5 years.
With licensed free RF modules for wireless transmission,
messages from multiple transmitters within a area can be
received and/or repeated, the real-time monitoring and
early warning for landslide or slope safety can be
achieved. |
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◎ Precise, Stable, False Alarm Prevention,
Cost-effective Advantages of such a method over
conventional methods include the following: real time
response to geo-deformation, precise displacement data;
no need of filtering of cyclic fluctuations associated
to daily cycle/year cycle and immunity to
electromagnetic interference.
Through TWSI Digital Extensometer deployed at various
locations, the displacement data derived from cable
extension can be interpreted as various degrees of slope
failure clearly. |
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Precision, Event-Trigger, Wireless and Lightning-free
Real-time Displacement Monitoring
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with
Digital Extensometers and Wireless Transmitter
Set up a warning system and/or repeater station in a
suitable location within the transmission distance to
receive signals from multiple transmitters. Besides the
signal of displacement, it can receive other signals of
crack,
groundwater, and soil saturation status, etc.
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Detects the signal of displacement based on the
amount and rate to identify different levels of
landslide event and
provides an alarm signal.
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Provides the signal periodically
so as
to ensure stable operation and also indicate the
power status. |
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Low power RF with transmission ranging up to
2km (with optional module)
reduces the equipment and installation cost and
power requirement.
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Extended cable up to a maximum of 400cm can reflect the
landslide status. |
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Debris flow monitoring
The transmitter is set in the stream.
It monitors the displacement of anchors or big rock in the stream bed
and will provide an alarm signal based on the
amount and rate of displacement transmitted from
the trigger pulse. |
Landslide Monitoring
The transmitter is set in the upper and/or lower
slope.
It monitors the potential and status of
landslide, and will provide the signal per 1mm
displacement and will trigger alarm according to
the
velocity
change in the
shallow ground. |
Rock-fall Warning
The transmitter is set on the Rock-Fall
Catch Fencing.
It provides the signal
per 1mm displacement. According to the amount of the rock-fall, the station can warn the
roadway users in time. |
Debris flow warning
The transmitter is set in a slit dam or a
debris dam.
It provides the signal in the process of flow squeezing
action and will trigger alarm based on the
amount and rate of displacement transmitted from
the trigger pulse.
When the intensity of debris flow increases, it
may make the
cable
broken or even departed from the snap. |
Roadway slope Monitoring
The transmitter is set in the roadway
embankment.
It monitors the potential and status at the
ground surface across the head scarp of the
lower slide and will provide the signal per 1mm
displacement, and trigger alarm according to the
velocity
change.
The cable can extend from one side of the
failure zone to the other side through a
flexible pipe buried in the trench. |
Settlement
monitoring
The transmitter is set on a ground surface.
Anchors are mounted at the bottom of a borehole. The transmitter
measures the amount of displacement between the
anchors and the transducer base. It will also
provide an alarm signal when the
trigger pulse
exceeds a
preset level.
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Evolution of Landslide Monitoring
Digital Extensometers and Wireless Transmitter |
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Highlight
Ø
With
absolute
position
data output,
no care must be taken to avoid noise and fluctuation.
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Actual
landslide event
can be triggered by pulse signal
to transmitter for data acquisition and disaster
warning.
Ø
Battery powered wireless transmission
is easy for installation and can achieve maximum
safety from
lightening damage.
Background
Since the conventional geotechnical instrumentation
has been
based on analog sensors, so the user must measure
the resistance, voltage, and current or vibrating
wire frequency. The analog type sensor such as
strain gauge, potentiometer,
and those which with output DC4~20mA, are excited
mostly by an
external power
source,
and needs a warm-up period to move to the stable
state, and by means of ADC, to obtain an averaged
digital data in order to have a realistic variance.
Temperature
effect and electromagnetic interference also have
impact on the realistic variance. When it comes to
dynamic
measurement
of
displacement,
the interval of periodic measurement should be
shortened, therefore it will consume more power and
must equip with
a larger solar panel or an AC power having a battery
back up. In this case, to address the issue of
lightning risk, more cost will also be introduced.
Rationale
The Digital
Extensometer
uses a constant
torque spring,
which controls cable tension while cable extension
rotates a precision potentiometer.
Once the objective moves, it pulls the
cable and
the signal corresponding to the
length
and the
direction
of displacement
will be produced with a multi-polar magnetic disk
and dual reed switches. The internal CMOS module of
the encoder enables the serial data output for
displacement in absolute format.
If no variations
occur, encoder and
transmitter consume little power, when
variations
occur; the reed switch
goes on/off and produces a pulse to trigger
the transmitter and the digital displacement data
can be received for
real-time data acquisition.
Performance
Ø
Reed switch activates the built-in absolute encoder; stable
data corresponding to mechanism displacement without
fluctuation and precise parameter for warning
threshold can be obtained.
Ø
Li-battery mounted in the PCB of the CMOS module
enables
continues
counting
when the transducer is disconnected with the
transmitter or logger.
Ø
Long stroke up to 400cm with 1mm precision signals
transmitted to station in event trigger mode; the
amount and rate of displacement signal can be
considered the best indicator of various deformation
conditions or the
failure
process.
Ø
Wireless transmission ranging up to 2km (with optional
module); 8~16 monitoring sites can be covered to
send
simultaneously
the signals to logger or warning station;
with a RF receiver, it can form a repeater station
or a main station.
Ø
Adaptable, easy to install as a stand-alone warning system or
upgrade existing alert stations with additional
sensors or an updated data logger for soil and water
monitoring.
Applications
Debris flow warning
Landslide Monitoring
Slide surface monitoring
Monitoring
of depth to the landslide
slip-plane
Settlement monitoring
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Innovative Instruments for
Landslide and Flash Flood |
Data Acquisition and Repeater (TW-86RT)
1.
Input:Contact
closure for Rain and RS-232 for wireless
Receiver
2.
Power:Solar
with built-in battery
3.
Display:4x16
LCD data display
4.
Output:RS-232
to GPRS and FSK to VHF Transmitter
5.
Data logger:512k
Flash memory
Data intervals:1/5/10/60
minutes |
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Digital Wire Extensometer (TW-231S)
1.
Type:Constant
torque spring loaded
2.
Measuring Range:4m
3.
Resolution:1
mm
4.
Accuracy:±
0.1 % F.S.
5.
Pulse signal:20
ms pulse for
every
1mm increment
/
decrement
6.
Output:Absolute
Serial Data String
7.
Wire tension:1.5kg
8.
Measuring Cable:Diameter
0.9mm nylon-coated stainless steel
9. External tension wire:30m length
Maximum |
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Wireless Transmitter (TW-348T)
1.
Tx interval:1/10
minutes and triggered by pulse
2.
Display:4
digit 10mm LCD
3.
Frequency:433/434MHz
4.
Data string
:Header+
ID code+ data value+CRC-16
5.
RF power:25
mW
6.Power supply:DC 6V battery or 3.6V lithium
battery; replaceable once per 2~5 year. |
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Wireless Receiver (TW-348R)
1.
Frequency:433MHz/434MHz
2.
Data Rx:Header
+ID code+ data value+CRC-16
3.
Range:By
Tx power (700 m)
4.
Standby current:10
mA
5.
Display:10mm LCD
6.Output:RS-232/RS-485 port, ID+ data string;
with additional output port for wireless rain
gauge
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Smart StormPanel (TW-86RP/TW-84RP)
1.
Displays:11sets,
4digits, 25mm character height red LED display.
2.
Dynamic displays:Dynamic
integrate and display for 10min to 24hrs, with
six items of rainfall intensity and accumulated
rainfall
3.
Alert function:The
built-in buzzer alert device automatically can
sound alarm when values exceed pre-set threshold
value.
4.
Power-saving & backup:Smart
power saving mode, the panel works for more than
36 hrs with built-in battery during AC power
failure.
5.
Data logger:The
built-in 512k flash memory can store rainfall
data for 420 days (5min/per).
6.Dimensions:650x350x60mm, wall hanging
weatherproof coated aluminum frame. |
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Rain Gauge (TW-210S)
1.
Type:Tipping-bucket
2.
Orifice:200±6 mm
3.
Resolution:0.5 mm/pulse
4.
Accuracy:≦±3
%
5. Material:S304
stainless steel |
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Cable-Extension Float-Operated level transducer (TW-264S/TW-265S)
1. Type:Float
operated, spring loaded (suspended by single
steel cable)
2.
Range:6/10m
3.
Resolution:5
mm /2mm
4.
Accuracy:±
0.1 % F.S.
5. Output:Absolute Serial Data String Stilling
well:∮4~6 inch |
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Wireless Landslide Monitoring System in Rambla Pacifico
CA. USA, 2012 |
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Fault zone monitoring collapse in GiSo China,2011 |
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The dip slope slip monitoring in HuNan China, 2011 |
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More Description |
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