Naslov
The Grohovo Landslide Monitoring System - Experiences from 18 months period of monitoring system operating

Autori
Ljutić, Kristijan ; Jagodnik, Vedran ; Vivoda, Martina ; Dugonjić Jovančević, Sanja ; Arbanas, Željko

Vrsta, podvrsta i kategorija rada
Radovi u zbornicima skupova, cjeloviti rad (in extenso), znanstveni

Izvornik
1st Regional Symposium on Landslides in the Adriatic-Balkan Region "Landslide and Flood Hazard Assessment" : proceedings / Mihalić Arbanas, Snježana ; Arbanas, Željko - Zagreb : Hrvatska grupa za klizišta, 2014, 45-50

ISBN
978-953-6953-43-1

Skup
Regional Symposium on Landslides in the Adriatic-Balkan Region (1 ; 2013)

Mjesto i datum
Zagreb, Hrvatska, 06.03.2013. - 09.03.2013

Vrsta sudjelovanja
Predavanje

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
monitoring system; calibrating equipment; measurement data

Sažetak
The Grohovo Landslide, the largest active landslide along the Croatian part of the Adriatic coast, is located on the north-eastern slope of the Rječina Valley. In 2009, the Croatian- Japanese research joint project “Risk identification and Land-Use Planning for Disaster Mitigation of Landslides and Floods in Croatia” was initiated and the Grohovo Landslide was chosen as a pilot area for a monitoring system development. A comprehensive monitoring system was designed, consisted of geodetical and geotechnical monitoring equipment which installation was started in March 2011, and in major part completed till the end of 2011. Integrated monitoring system generally can be divided in two major parts. One part is geodetical, consisted of GPS system (9 rovers and 1 master unit), and robotic total station with 24 geodetical prisms. Second part is geotechnical one, consisted of pore pressure gauges, inclinometers and extensometers. Establishment of the monitoring system was carried out in stages according to monitoring equipment purchasing process and its delivery. Installation of inclinometer casings and pore pressure gauges was started in March 2011, and foundations and poles for long span extensometers finished in May 2011. Main part of geodetical monitoring equipment was installed in July 2011. After monitoring system was powered up and turned on, several problems in equipment functioning were observed and equipment re-adjustment was carried out until the end of November 2011. Installation of long span extensometers was completed until the end of 2011, while the short span extensometers, vertical extensometers and pore pressure gauge data loggers were installed during the year 2012. Observations from geodetic prisms with robotic total station and GPS system are collected and processed in the automated integrated monitoring system software. Geotechnical part of the equipment (long and short span extensometers, pore pressure gauge, rain gauge) should be included in the same integrated system during February and March 2013. During the first 18 months of monitoring system was being operating, equipment calibration, system improvement and maintenance took considerable part of the system establishment. The first 12 months period of data collection was needed for understanding relation between disturbing effects and their causes and procedures for calibrating equipment and eliminating effects of weather impacts on measurements accuracy was established. Seasonal meteorological and atmospherical conditions influenced on the system not only from the measurements point of view. Extreme temperatures during late June and whole July 2012 influenced in uneven bending deformation of the main pillar which affected on total station's position and leaning, and consequently - its measurements. During the spring and summer time, vegetation blocked the view from the total station to the several prisms located in the forested part of the landslide. While solar panel system for GPS rovers at the landslide are sufficient for electric energy production, hybrid power system consisted of 1 kW solar panels and 500 W wind mill located at Veli vrh, during the late autumn and winter is not able to efficiently produce enough electric energy to keep main computer workstation, robotic total station, GPS, web camera and wireless network system continuously working, especially during continues cloudy days. However, collected measurement data are sufficient for observing the landslide in whole period, because of their consistent data trends and correlation between different data sets. In this paper previously mentioned issues and problems are closely described, as well as solutions for them that we carried out to maintain the monitoring system for successful continuous work.

Izvorni jezik
Engleski

Znanstvena područja
Građevinarstvo, Rudarstvo, nafta i geološko inženjerstvo

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