| Employer: |
SOFIYSKA VODA – JSCo. |
| Project: |
Beli Iskar dam - Repair works - stage 1 |
| Subproject: |
Instrumentation system of the Dam |
| Design: |
Instrumentation system of the Dam |
| Main contractor: |
Start engineering Co. |
| Kinds of activities: |
Design (hardware and software), specification and
delivery of equipment, installation and commissioning |
| Performance: |
November 2002 - February 2003 | |
"Beli Iskar" dam is constructed in the
valley of Beli Iskar river, in Rila Mountain and is mainly used
for water supply of Sofia city.
The dam is concrete
gravity type, max height 51 m and crest length 533 m. Crest
Elevation is 1878.70 (above the sea level).
Short description of the project:
The project was performed by specialists of “Start
engineering” JSCo. on the basis of preliminary design
“Instrumentation system” of Energoproect – Hydroenergetika” EAD
and specific requirements of the employer.
The Instrumentation system comprises three independent subsystems:
®
Meteopark, where air temperature and humidity are being measured,
as well as barometric pressure, intensity of solar radiation,
precipitation. The data is gathered in microprocessor station
CR10X of Campbell Scientific, Inc. USA
®
System for monitoring of the dam which comprises:
- level gauge for the water level of the dam
- seepage measuring weirs, which measure the
infiltrated water flow, passed through the membrane, concrete and
drainage curtain under the dam
- piezometers, which monitor the water head in the dam body
- direct and inverted pendulums for horizontal displacements
of the dam crest and foundation
- thermometers for the concrete temperature
- jointmeter for surveillance of opening and closing of joints
The sensors for dam condition (with the exception of the
pendulums and the jointmeter) are of vibrating wire type, having
proven high reliability and security,
production of
GEOkON
USA
. The
signals from all sensors are gathered in four commutators
with multiplexers
(MUX), located in drainage gallery. From each MUX through a
common cable
the signals are sent to the Central Measuring Station.
®
Seismic system for registering of earth fluctuations,
consisting of a GPS antenna and three
accelerometers, two of
which are interconnected. The seismic equipment is from
GeoSIG Switzerland.
The equipment for the meteopark and the
instrumentation system for monitoring the dam are supplied by
GEOkON
USA
.
The cabinet with the central measuring
station Micro10 (based on CR10X) of Campbell Scientific, Inc. USA
is installed in the newly erected
building for the
purposes of the instrumentation system. The data gathered
there are sent through serial interface to the Operator’s station
– HP OMNIBOOK XE 4500 and is used by means of
MultiLogger2
Canary.
The
meteorological data gathered in CR10X, also through a serial
interface, are being handled and processed by means of PC200W.
Exept in tables, this data can be also represented as
trends.
GeodaS is the software, by means of which
records of seismic events are being taken out of the
accelerographs.
Micro10 is powered by rechargeable battery
12V, which is being charged by mains rectifier.
CR10X in the meteopark is also powered by
rechargeable battery 12V, which on its part is being charged by a
solar panel during the daytime.
Due to the increased danger of damages in the
presence of seasonal lightning activity and problems with the
power supply, the microprocessor equipment is provided with
two-stage overvoltage protections.
A new survey network was constructed for
monitoring the displacements of outside points of the dam and for
monitoring the bottom silts.
The team
