CN102587983B - Comprehensive early-warning observation method for coal mine rock burst - Google Patents

Abstract

The invention discloses a coal mine rock burst comprehensive early warning observation method, which first obtains the high stress field range of the rock burst coal seam; then artificially interferes and observes the disturbance range; and finally monitors all-round dynamics. In the present invention, the movement damage of the overlying rock in the excavation face is closely connected with the stress size and distribution of the stress field for comprehensive monitoring, so as to predict the risk of rock burst and take timely alarm measures to avoid the occurrence of dangerous rock burst accidents.

Description

Comprehensive early warning and observation method of coal mine rock burst

technical field

The invention belongs to the technical field of coal mining.

Background technique

Rock burst is one of the most serious natural disasters in coal mines worldwide. The coal seams and rock formations in most mines in my country have different degrees of impact tendency. At a certain critical depth, the impact of coal and rock is extremely serious, especially as the mining depth of my country's coal mines continues to increase at a depth of about 20m per year. It has become more and more serious and has become one of the major catastrophic accidents restricting mine production and safety in my country. Although scholars at home and abroad have made important progress in the research on the mechanism of rock burst, monitoring methods and control technology, it is far from fundamentally solving the problem of its effective prediction and prevention. Most of the coal mines in my country were built in the 1950s and 1960s. With the passage of time and the development of mineral resources moving to the deep, these mines will enter deep mining, and the problem of rock burst disasters will become more serious, more prominent, and more common.

In terms of prediction and prevention of rock burst, due to the unclear movement of the overlying strata after mining and the spatio-temporal distribution of the stress field of the surrounding rock in the stope, the decision-making theory of development and recovery is not perfect. The design basically relies on statistical experience to make decisions, so mining work often occurs in high-stress areas, islands and semi-isolated coal pillars, providing a source of force for the occurrence of rock bursts. Due to the lack of grasp of the intrinsic law of the failure process of rock burst under the conditions of complex high stress and large burial depth, the time, place and intensity of rock burst occurrence have not reached the level of quantitative prediction; Information collection technology, its test parameters are not perfect, and the monitoring information is not very reliable, so it can only conduct qualitative monitoring of rock burst; the monitored information has not been comprehensively processed in theory, experiment, and method, and its feedback information The reliability of rock burst prediction is poor. Therefore, the current rockburst control is comprehensive prevention and control, which causes a lot of waste of manpower and material resources, greatly affects the production organization, and reduces production efficiency. In recent years, significant progress has been made in the research of rock burst prediction and prediction, but there is no systematic and reliable observation method in terms of the dynamic stress range and the quantitative observation of energy release characteristics in high stress areas, especially Especially under the condition of deep wells, the softening effect of the rock formation is obvious, and it is difficult to establish the judgment criterion of the dynamic stress range, and it is difficult to obtain quantitative values with the current observation means and methods. .

Therefore, the mining design and implementation of rockburst coal seams in my country's coal mines are still in the development stage where the development laws of mining overlying rock movement and stress field distribution are unclear. This is one of the important reasons for the frequent rockburst accidents in coal mines, especially the major disaster accidents that have not been fundamentally controlled, and the economic benefits of mining are low. Theoretical research and production practice have proved that almost all rock burst accidents are closely related to the movement damage of the overlying rock in the mining face and the magnitude and distribution of stress in the stress field.

Contents of the invention

The purpose of the present invention is to propose a comprehensive early warning observation method in order to improve the reliability of coal mine rock burst risk prediction.

The technical scheme that the present invention takes is:

Step 1: Obtain the high stress field range of rockburst coal seams

During the mining process of rock burst coal seam, firstly, along the advancing direction of the working face in the mining roadway, a roof dynamic instrument is arranged at intervals of 10-20 meters to continuously observe the roof sinking speed, so as to obtain the sudden change of roof sinking speed Then gradually reduce the interval distance of the roof dynamic instrument at this location, and continue to observe the roof sinking velocity continuously until it approaches the accurate leading pressure range value, which is determined as the roof high stress field range.

Step 2: Human intervention to observe the disturbance range

In the mining roadway, starting from the edge of the high stress field, a high-sensitivity strain gauge is arranged at intervals of 5-10m along the advancing direction of the working face, and more than 4 sets are arranged; Drill 3-5 holes with a hole spacing of 3-5m and a hole depth of 8-10m. Fill the holes with explosives and blast once; after the blasting, the detonation wave propagates in the coal seam and gradually attenuates. Stress wave data, according to the size of each stress wave display data to determine the disturbance range of energy release in the dynamic pressure zone.

The third step: all-round dynamic monitoring

In the roadway within the high stress field range and disturbance range determined above, arrange and bury multiple groups of sensitive pressure sensors. 2-3 sensitive pressure sensors per m, and the sensors of each group are at different depths; when burying, first drill holes into the surrounding rock, pour the sensitive pressure sensors in the drill holes, and transmit the sensor signals to the data acquisition and processing In the mining of the working face, the data acquisition processor processes the change data of the stress field in time, and when the early warning parameters set by the system are reached, an alarm is issued, so as to realize the monitoring and early warning of the coal mine rock burst risk.

The positive effect of the present invention is: by closely linking the movement damage of the overlying rock in the mining face with the stress size and distribution of the stress field for comprehensive monitoring, the danger of rock burst can be predicted and timely alarm measures can be taken to avoid rock burst occurrence of dangerous accidents.

Description of drawings

Fig. 1 is a roof dynamic instrument arrangement and a schematic diagram of a dynamic stress field of the present invention;

Fig. 2 is a schematic diagram of the arrangement of human intervention inducing and observing instruments of the present invention;

Fig. 3 is a schematic diagram of omni-directional dynamic monitoring of the present invention.

Detailed ways

The implementation of the present invention will be described below in conjunction with the accompanying drawings.

Step 1: Obtain the range of dynamic stress field

As shown in Figure 1, during the mining process of rock burst coal seam working face, a roof dynamic instrument is arranged at intervals of 10-20 meters along the advancing direction of the working face in the mining roadway to continuously observe the roof sinking speed, thereby Obtain the location where the roof sinking velocity changes suddenly; then gradually reduce the distance between the roof dynamic instruments at this location, and continue to observe the roof sinking velocity continuously until it approaches the accurate leading pressure range value, which is determined as the roof dynamic stress field range.

Step 2: Human intervention to determine the disturbance range

As shown in Figure 2, in the mining roadway, starting from the edge of the dynamic stress field, a high-sensitivity strain gauge is arranged at intervals of 5-10m along the advancing direction of the working face, and more than 4 sets are arranged; and within the range of the dynamic stress field Drill 3-5 holes into the coal seam at the stress peak position, the hole spacing is 3-5m, and the hole depth is 8-10m. The holes are filled with explosives and blasted at one time; after the blasting, the detonation wave propagates in the coal seam and gradually attenuates. Sensitive stress gauges observe and record stress wave data, and determine the disturbance range of energy release in the dynamic pressure zone according to the size of the data displayed by each stress wave.

The third step: all-round dynamic monitoring

In the roadway within the high stress field range and disturbance range determined above, arrange and bury several groups of sensitive pressure sensors, as shown in Fig. 2-3 sensitive pressure sensors with a spacing of 0.5m, and the sensors of each group are at different depths; when embedding, first drill holes into the surrounding rock, pour the sensitive pressure sensors in the drill holes, and place the sensors The signal is transmitted to the data acquisition processor; in the mining of the working face, the data acquisition processor processes the change data of the stress field in time, and when the early warning parameters set by the system are reached, an alarm is issued, so as to realize the monitoring and early warning of the coal mine rock burst risk.

Claims (1)

1. A coal mine rock burst comprehensive early warning observation method is characterized in that, Step 1: Obtain the high stress field range of rockburst coal seams During the mining process of rock burst coal seam, firstly, along the advancing direction of the working face in the mining roadway, a roof dynamic instrument is arranged at intervals of 10-20 meters to continuously observe the roof sinking speed, so as to obtain the sudden change of roof sinking speed Then gradually reduce the interval distance of the roof dynamic instrument at this location, and continue to observe the sinking velocity of the roof continuously until it approaches the accurate leading pressure range value, which is determined as the high stress field range of the roof; Step 2: Human intervention to observe the disturbance range In the mining roadway, starting from the edge of the high stress field, a high-sensitivity strain gauge is arranged at intervals of 5-10m along the advancing direction of the working face, and more than four sets are arranged; Drill 3-5 holes with a hole spacing of 3-5m and a hole depth of 8-10m. Fill the holes with explosives and blast once; after the blasting, the detonation wave propagates in the coal seam and gradually attenuates. Stress wave data, according to the size of each stress wave display data to determine the disturbance range of energy release in the dynamic pressure zone; The third step: all-round dynamic monitoring In the roadway within the high stress field range and disturbance range determined above, arrange and bury multiple groups of sensitive pressure sensors. 0.5m sensitive pressure sensor, and the sensors of each group are at different depths; when burying, first drill holes into the surrounding rock, pour the sensitive pressure sensors in the drill holes, and transmit the sensor signals to the data acquisition processor; In the mining of the working face, the data acquisition processor processes the change data of the stress field in time, and when the early warning parameters set by the system are reached, an alarm is issued, so as to realize the monitoring and early warning of the risk of coal mine rock burst.

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