Geological Hazard Monitoring Geological Disaster Publicity ---- General Knowledge of Geological Hazard Monitoring and Management Techniques

Geological Hazard Monitoring and Treatment Technology

The main content of geological hazard monitoring is to monitor the deformation and damage information (including deformation, geophysical field, chemical field, etc.) and the dynamic information of triggering factors of geological hazards in the spatial and temporal domains. Maximize the acquisition of continuous spatial deformation and damage information and continuous deformation and damage information in the time domain, focusing on the acquisition of dynamic information in the time domain. It is applied to the stability evaluation, prediction and forecasting of geologic hazards and the evaluation of the effect of prevention and control works. The main purposes of geologic disaster monitoring are: to identify the deformation characteristics of the disaster body, to provide a basis for the prevention and control of engineering design; construction safety monitoring, to ensure construction safety; prevention and control of engineering effect monitoring; not suitable for dealing with or very dangerous disaster body, monitoring its dynamics, timely alarm, to prevent casualties and major economic losses.

Geological disaster professional monitoring technology methods:

The so-called professional monitoring of geological disasters refers to the professional and technical personnel in the professional investigation on the basis of professional instruments and equipment and professional technology, the deformation of geological hazards dynamics of monitoring, analysis and prediction of a series of professional and technical integrated application.

1, collapse, landslide monitoring technology

1) surface deformation monitoring

① surface relative displacement monitoring: the main method of mechanical seam method, expansion meter method, telemetry displacement meter monitoring method and surface tilt monitoring method.

② Absolute surface displacement monitoring: the main methods are geodesic deformation measurement, close-up photogrammetry, laser micro-displacement measurement, surface displacement GPS measurement, laser scanning method, remote sensing (RS) measurement and synthetic aperture radar interferometry.

2) Deep displacement monitoring: the main methods are seam detection method, borehole tilt measurement method and borehole displacement meter monitoring method.

3) Groundwater dynamic monitoring : The main monitoring methods are groundwater level monitoring method, pore water pressure monitoring method and water quality monitoring method.

4) Related factors monitoring: the main methods are geoacoustic monitoring method, stress monitoring method, strain monitoring method, radioactive gas measurement method and meteorological monitoring method (rain gauge, snowmelt meter, hygrometer and thermometer).

2, mudslide monitoring technology methods: mudslide monitoring methods are mainly acoustic monitoring method, faucet height monitoring method, mud level monitoring method, tilt meter stick monitoring method, flow rate monitoring method, pore water pressure monitoring method and rainfall monitoring method.

Second, the geological disaster simple monitoring technology method

The so-called geological disaster simple monitoring, refers to the use of simple measuring tools, instrumentation and measurement methods, monitoring the disaster body, houses or structures cracks displacement changes in the monitoring method. This type of monitoring method has the characteristics of fast input, easy operation and intuitive data, that is, it can be used by professional and technical personnel as an auxiliary method, and can also be used by non-professional technical personnel after training, which is a common monitoring method in the group monitoring and prevention of geologic hazards.

This type of monitoring generally commonly used monitoring methods are:

1) buried piles: buried piles are suitable for the collapse, landslides occurring on the cracks to observe. In the slope across the cracks on both sides of the buried piles, with a steel tape measure to measure the distance between the piles, you can understand the landslide deformation sliding process. For soil cracks, buried piles can not be too close to the cracks.

2) buried nail method: in the building cracks on both sides of a nail, by measuring the distance between the two nails on both sides of the change to determine the deformation of the landslide sliding. This method is very effective for the judgment of the precursor of the disaster.

3) paint method: in the building cracks on both sides of the paint on each side of a mark, and buried nails is the same principle, through the measurement of the distance between the two sides of the mark to determine whether there is an expansion of cracks.

4) patch method: across the building cracks paste cement mortar sheet or paper, if the mortar sheet or paper sheet was

pulled off, indicating that the landslide occurred in the obvious deformation, must take precautions. Compared with the above three methods, this method can not obtain specific data, but can be very direct judgment of the sudden change of the landslide. Geological disaster cluster monitoring method in addition to the use of buried stakes, patch method and disaster precursor observation and other simple methods, but also with the help of simple, fast, practical, easy to grasp displacement, ground sound, rain and other cluster early warning devices and simple sound, light, electric alarm signaling device to improve the accuracy of early warning and rapid response capability of the disaster.

For landslide and landslide disaster group testing and prevention monitoring, you can use crack alarms, landslide early warning telescope (large range, threshold alarm, suitable for all kinds of landslide crack monitoring), simple crack displacement meter (high precision, threshold alarm, multi-channel, suitable for rocky landslides and building crack monitoring), simple ultrasonic displacement meter (large range, non-contact, valve alarm, used in all kinds of landslides) and simple rain displacement meter (large range, non-contact, threshold alarm, used in all kinds of landslides). (large range, non-contact, threshold alarm, used in a variety of landslide monitoring) and simple rain gauge for monitoring and early warning.

For mudslide disaster group monitoring and prevention monitoring, you can use simple ground sound monitor (multi-channel, valve value alarm), mudslide video warning instrument (vibration or video changes trigger work) and simple rain gauge for monitoring and early warning.

Third, geological disasters macro-geological observation method

The so-called macro-geological observation method, is to use conventional geological survey methods, the collapse, landslide, mudflow disaster body of macro-deformation signs and its related anomalies on a regular basis for observation, recording, in order to keep abreast of the collapse, landslides deformation dynamics and development trends, to achieve the purpose of scientific forecasting. The method is characterized by intuition, dynamics, adaptability and practicability, not only applicable to the monitoring of different deformation stages of various types of collapse and landslide, but also rich in monitoring content, wide range, and the precursor information obtained is intuitive, reliable and highly credible. The method is simple and economical, easy to grasp and popularize. Macro-geological observation method can provide collapse landslide short-term forecast of reliable information, even with advanced instrumentation observation and automatic telemetry methods to monitor the deformation of the collapse and slide, the method is still indispensable.

In general, it is difficult to capture the short-term instantaneous macro-deformation traces and other anomalous phenomena on the slopes in sudden-onset disasters; while progressive disasters have obvious macro-deformation traces and other anomalous phenomena on the slopes in a certain period of time, which are called precursor information of disasters. Accurately capture these information and dynamic synthesis and analysis of these precursor information, disaster prevention and prediction, disaster mitigation and prevention is of great significance.

The occurrence of geological disasters usually has comprehensive precursors, and a single individual precursor to identify the disaster may cause misjudgment and bring adverse social impact. Therefore, when a precursor is found, it must be viewed as soon as possible, and a comprehensive judgment must be made quickly. If more than one precursor appears at the same time, you must quickly evacuate people and report to the local authorities as soon as possible.

Fourth, the number and timing of monitoring

Monitoring every 15 days in the dry season. Rainy season April-July monitoring every 5 days (such as the provisions of the 5th, 10th, 15th, 20th, 25th and 30th of each month), such as the monitoring of geologic hazards are found to have abnormal changes in the point or in the torrential rainfall, continuous rainfall weather, especially 12 hours of rainfall up to more than 50mm, should be encrypted to monitor the number of times, such as one or more times per day, or even around the clock to arrange for monitoring by special personnel.

Geological disaster engineering management

A collapse management project: remove dangerous rocks, for small scale, high risk of dangerous rock body to take blasting or manual methods to remove, eliminate dangerous rocks hidden danger; for larger scale collapse of dangerous rock body, can remove the upper dangerous rock body, reduce the height of the proximity, reduce the gradient, reduce the load on the upper part of the slope to improve the stability of slopes, so as to reduce the degree of danger of the collapse. To build surface drainage system in the collapse body and its periphery, and fill up the fissure holes to drain away the surface water, so as to reduce the chances of collapse; to reinforce the slope, improve the geotechnical structure of the collapse slope, and increase the structural integrity of the geotechnical body; to take support measures such as supporting piers and supporting walls to prevent and control the collapse; to take anchors to reinforce the dangerous rock body; to take reinforcing methods such as spraying slurry to protect the wall and embedded support to strengthen the soft foundation; and to take measures to strengthen the soft base of the slope where the collapse of falling rocks is expected to take place.

Platforms, troughs, walls, etc. are constructed in the path of rock rolling to intercept the falling rocks in the area where the collapse is expected to occur; and the project is protected through the construction of open caves, shelters, and other facilities.

Second landslide management project: eliminate or reduce the surface water, groundwater on the landslide triggering effect, the construction of drainage ditches, reduce the amount of water into the landslide body, and in a timely manner will be the development of landslides within the scope of the surface water exclusion, the construction of water interception blind ditch, excavation of seepage wells or interception of blind holes, laying of drainpipes, the implementation of drainage boreholes, interception of drainage and channeling of groundwater; to improve the condition of landslides, increase the conditions of balance of the landslides, the landslides in the upper part of the landslide Slope reduction, foot of the slope filling, reduce the center of gravity of the landslide; construction of anti-slip piles, anti-slip wall, anti-slip holes, to prevent landslides from moving; the implementation of anchoring works to strengthen the landslide, take the roasting method, electro-osmotic drainage method, grouting method and other measures to improve the nature of the rock and soil body of the landslide body and improve the strength of the soft rock layer.

Third, mudslide management project: the implementation of biological engineering to protect soil and water, weaken the conditions of mudslide activities, the protection of forest vegetation, reasonable farming and grazing, and strictly prohibit indiscriminate cutting and logging, and improve the vegetation coverage; the implementation of engineering measures to limit the activities of mudslides, the construction of blocking, drainage, stopping siltation, ditch remediation and other projects to weaken the destructive power of mudslides, mudflow areas of the railroads, highways, bridges, tunnels, houses, and other buildings to protect or avoid, and the implementation of engineering measures. For railroads, highways, bridges, tunnels, houses and other buildings in the mudslide area to protect or avoid, resist or avoid mudslide disasters.