Landslide refers to the effect and phenomenon that a certain part of the rock and soil on the slope of the mountain slope moves to the bottom of the slope as a whole due to shear displacement along a certain weak structural plane (zone) under the action of gravity (including the gravity of the rock and soil itself and the dynamic and static pressure of groundwater). It is commonly known as "walking the mountain", "breaking the mountain", "slippery ground", "slippery" and so on. It is one of the common geological hazards, according to the industry norms to develop a landslide monitoring solution, the key elements of the stability of the image mountain slope online monitoring, provide all-weather real-time data, for monitoring and early warning to provide first-hand data support, the main monitoring methods are as follows.
1. Crack monitoring
Cracks are the main precursors of landslides, which generally occur at the front edge of landslides and are caused by cracks in the ground. Crack monitoring can be divided into macro crack monitoring and micro crack monitoring.
Macroscopic crack monitoring is mainly set up at the front edge of the landslide body, the observation point should be set in the landslide body can not be directly in contact with the surface of the place, and it is advisable to choose the corner of the building or the corner of the superstructure, the frequency of observation is once a year, and the observation record is made at the same time.
Observation points should be set up near the trailing edge of the landslide and lame, and observation records should be made. Under normal circumstances, macroscopic crack monitoring cannot meet the requirements of landslide disaster forecasting and early warning, and microscopic crack monitoring should be strengthened.
2. Ground deformation monitoring
Ground deformation monitoring mainly refers to the setting of ground deformation observation stations on the ground to monitor the horizontal displacement changes of the ground. In the ground deformation observation station, representative monitoring points should be selected to study the long-term change trend of the land surface and the relationship between displacement and time change.
According to the monitoring purpose and requirements, the ground terrain observation station should be selected in the area with the greatest surface movement or the most frequent landslide, or in the area with complex geological structure, landslide development, low vegetation coverage, complex topography and landform, and greatly affected by human engineering activities. The monitoring point should be selected in an area where the topography and geotechnical properties are basically stable.
3. Groundwater monitoring
The change of groundwater is closely related to the development and stability of landslides. The cracks at the trailing edge of landslides are often above the groundwater level, so the groundwater level at the trailing edge of landslides is one of the key points of monitoring. Groundwater monitoring can be monitored by electroosmosis method, seepage pressure method and other methods, and can be combined with displacement monitoring, such as water level changes in the front edge of the landslide when there is a large deformation, often accompanied by obvious groundwater changes.
Fourth, water level change monitoring
The monitoring of water level change can be divided into two types: observation well water level and reservoir bank water level. The observation well water level is a water level observation hole set at a certain depth of the landslide body, and the hole buries the groundwater gauge through the borehole. The water level of the reservoir bank refers to the groundwater level at a certain depth of the reservoir bank, which is generally located in the river beach near the landslide body.
5. Atmospheric precipitation monitoring
Atmospheric precipitation monitoring is to set up a certain number of meteorological stations at appropriate locations outside the landslide danger area and the danger area to monitor the intensity, total amount and spatial distribution characteristics of atmospheric precipitation, and compare them with the rainfall monitoring data to analyze the possibility of landslide. According to the atmospheric precipitation observation data and rainfall data, the landslide danger area and the scope of the danger area are determined. Atmospheric precipitation observation equipment can be arranged on the landslide body of the landslide, and can also be arranged around the landslide body, generally at certain intervals. The purpose of monitoring atmospheric precipitation is to understand the impact and development trend of atmospheric precipitation on landslides in a timely manner.
Landslide monitoring is a professional, technical and systematic work, which requires the full cooperation and cooperation of experts from all walks of life. By strengthening the monitoring of landslides, we can effectively prevent and reduce the occurrence of landslide disasters and ensure the safety of people's lives and property.