Monitoring of Landslide
Last update time : 02/10/2018
Landslide online monitoring resolution
Landslide refers that some rocks and soils on a mountain slope move downward due to the shear displacement that occurs along a certain weak structural plane (belt) under the action of gravity (including the gravity of rocks and soils as well as the pressure of groundwater). It is one of the common geological disasters.
As lots of engineering work is necessary in the course of China’s economic growth, if geological survey and protection are inadequate during engineering work, then, geological conditions, as well as the mountain slope and hydrological conditions will change greatly, resulting in more geological hazards, including landslides. In recent years, the increasing incidence of landslides has seriously threatened people’s lives and property. So many research institutes and enterprises explore and analyze causes behind those landslides and come up with solutions pertinently.
After a vast amount of observations and summaries, it’s discovered that a landslide is subject to the following four conditions:
Soil type: Rocks and soils with loose structure, poor shear strength and weather resistance, as well as changeable properties under the action of water. For example, loose coating, loess, red clay, shale and mudstone are soil types that pose a threat for landslides.
Geological structure conditions: Rocks and soils that make up a slope can only slide downward if they are cut into discontinuous shapes by various structural planes.
Geographic and geomorphic conditions: Landslides can only be caused with certain landforms of certain slopes. Slopes, greater than 10 degrees or less than 45 degrees, steep at the bottom and top (which is ring-shaped) in the middle, are favorable landforms for landslides.
Hydrogeological conditions: The movement of underground water plays a main role in the formation of landslides. Its functions are mainly softening rocks and soils, reducing the intensity of rocks and soils, producing hydrodynamic pressure and porewater pressure, forming subsurface erosion, increasing the unit weight of rocks and soils, generating uplift pressure to the permeable stratum, etc. Among them, the softening of sliding surfaces (planes) and reduction of intensity are most prominent.
Provided the four conditions, landslides may occur as long as inducing factors are in place. Common inducing factors are: earthquakes, rainfall and snowmelt, surface water erosion, soaking, unreasonable human engineering activities.
Prevention should be prioritized to address landslides and monitoring mountain areas that may threaten people’s lives and property can yet be regarded as a good method among others.
Geomative has established an online monitoring system for landslides taking the independently developed Geomative direct current electrical instrument as the core, integrated with the TDR sensor and rainfall sensor, in combination with the wireless network technology and cloud platform technology, which can conduct remote monitoring to areas where landslides are prone to occur. The rainfall sensor can timely report the precipitation of the area, as the occurrence of landslides is closely linked with the soil’s water content. On the side slope, measuring lines of electrical instrument products are deployed according to specific circumstances to regularly monitor the change of soil resistivity and deduce the stratigraphic structure and changes of water content. At the same time, the TDR sensor has coaxial lines that can convert the soil displacement data into electrical signal and report. Geomative landslide monitoring system is a good example of the successful combination of displacement and imaging methods. The following is a system diagram:
The system is composed of the following modules:
- Direct current electrical products
- Sensors including rain gauge and TDR
- Geomornitor controller
- Power supply module
- Geo Could server
- Client software
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