High-sensitivity monitoring solutions are crucial for early warning systems of earth structures. In this paper, we discuss the design and implementation of such systems for natural and engineered slopes using two case...High-sensitivity monitoring solutions are crucial for early warning systems of earth structures. In this paper, we discuss the design and implementation of such systems for natural and engineered slopes using two case studies. At the Gradenbach Observatory, one key element of the monitoring system is a large fiber optic strain rosette embedded in the slope. We demonstrate that the strain rosette can depict landslide deformations much earlier than geodetic sensors like GPS or total stations and is therefore well suitable for an early warning system. In a second application we report the construction of a reinforced earth structure using geogrids. A distributed fiber optic measurement system was installed to measure the current operating grade of the geogrids within the earth structure. About 2 km of Brillouin sensing cables were installed in the project area. It is demonstrated that the developed monitoring system is well suited for assessing the current state of health of reinforced earth structures.展开更多
Landslide risk is increasing in many parts of the world due to growth of population and infrastructures. Therefore, an effort has to be made in developing new and cheap sensors for areas susceptible of landslides to c...Landslide risk is increasing in many parts of the world due to growth of population and infrastructures. Therefore, an effort has to be made in developing new and cheap sensors for areas susceptible of landslides to continuously control the slope behaviour, until approaching failure conditions. The paper reported experimental data from smallscale physical models about the performance of Time Domain Reflectometry(TDR) and optical fibres, which act as the indicators of the incoming failure of slopes covered by unsaturated granular soils. Obtained results appear encouraging, since both sensors provide continuous information about the state of the slope, in terms of water content profiles and ongoing deformations, induced by rainwater infiltration, even immediately before the triggering of a fast landslide.展开更多
We propose a technique for chromatic dispersion monitoring based on optical time domain level monitoring. Experimental and simulation results show that the technique is effective for the monitoring of dispersion in 42...We propose a technique for chromatic dispersion monitoring based on optical time domain level monitoring. Experimental and simulation results show that the technique is effective for the monitoring of dispersion in 42.7-Gbps CS-RZ signals for dynamic dispersion compensation.展开更多
基金the Austrian Academy of Sciences(OeAW)for funding the landslide monitoring project for several yearsthe Austrian Federal Railways(OBB)for the funding of the geogrid monitoring project,especially the participating departments of OBB-Infrastruktur AG:Tunneling,Surveying and Data Management,Research and Development
文摘High-sensitivity monitoring solutions are crucial for early warning systems of earth structures. In this paper, we discuss the design and implementation of such systems for natural and engineered slopes using two case studies. At the Gradenbach Observatory, one key element of the monitoring system is a large fiber optic strain rosette embedded in the slope. We demonstrate that the strain rosette can depict landslide deformations much earlier than geodetic sensors like GPS or total stations and is therefore well suitable for an early warning system. In a second application we report the construction of a reinforced earth structure using geogrids. A distributed fiber optic measurement system was installed to measure the current operating grade of the geogrids within the earth structure. About 2 km of Brillouin sensing cables were installed in the project area. It is demonstrated that the developed monitoring system is well suited for assessing the current state of health of reinforced earth structures.
基金partially supported by the project Safe Land "Living with landslide risk in Europe: Assessment, effects of global change, and risk management strategies" under Grant No. 226479 (7th Framework Programme)
文摘Landslide risk is increasing in many parts of the world due to growth of population and infrastructures. Therefore, an effort has to be made in developing new and cheap sensors for areas susceptible of landslides to continuously control the slope behaviour, until approaching failure conditions. The paper reported experimental data from smallscale physical models about the performance of Time Domain Reflectometry(TDR) and optical fibres, which act as the indicators of the incoming failure of slopes covered by unsaturated granular soils. Obtained results appear encouraging, since both sensors provide continuous information about the state of the slope, in terms of water content profiles and ongoing deformations, induced by rainwater infiltration, even immediately before the triggering of a fast landslide.
文摘We propose a technique for chromatic dispersion monitoring based on optical time domain level monitoring. Experimental and simulation results show that the technique is effective for the monitoring of dispersion in 42.7-Gbps CS-RZ signals for dynamic dispersion compensation.
