What is the permeability of coal mine?

Question 1: What's the matter with mine flooding? In the process of mine construction and production, surface water and groundwater flow into the mine through various channels. When the mine water inflow exceeds the normal drainage capacity, it will cause mine flood. Mine flood (usually called water seepage) is one of the common major disasters in coal mines. Once water seepage occurs, it will not only affect the normal production of the mine, but also cause casualties and flood the mine and mining area, which is very serious. Therefore, doing well in mine waterproofing is one of the important contents to ensure mine safety production. Mine water sources are divided into surface water and groundwater. (1) Mine flood caused by surface water. When there are rivers, lakes, ponds, reservoirs, ditches and other accumulated water near the mine, as well as seasonal rainfall, the water level soars beyond the elevation of the mine wellhead and flows into the ground, or cracks, faults or subsidence areas seep into the ground to cause floods, this water source is called surface water. Generally, there are the following kinds of water disasters: 1) For mines located in low-lying areas, surface water breaks through the dams around the mines and flows into the wellhead, or due to improper dumping positions of rubble hill and furnace ash, it has been washed into nearby rivers by floods or rainwater for many years, increasing the riverbed or causing rivers to cross the dams or flood control dams and directly enter the wellhead. This surface water is fierce, accompanied by a lot of sediment and gravel. If improper preventive measures are taken, it will often cause flood accidents; 2) Surface water is connected with soft gravel layer. When the shaft is driven through the alluvium aquifer, the surface water will flow into the ground along the cracks in the gravel stratum, causing floods; 3) The surface water is connected with the aquifer of the roof and floor of coal seam or connected by faults, and the surface water enters the roadway through the aquifer or faults, causing flood accidents; 4) After coal mining, once caving zone enters the old kiln or is connected with the surface water system, surface water will also flood into the mine, causing flood accidents. (2) Mine flood caused by groundwater. Groundwater includes aquifer water, karst cave, fault water and old empty water. Generally speaking, there are the following kinds of floods caused by groundwater: 1) Underground conglomerate layer, quicksand layer and karst limestone layer all contain a lot of accumulated water, which is called aquifer. When the excavation work approaches or penetrates the stagnant water area, it will cause water seepage accidents; 2) The fault and its adjacent rock strata are relatively fractured, and sometimes the fracture carries water or communicates with surface water and aquifer. When driving, it is easy to cause water inrush accidents when encountering this situation. 3) There is often a lot of accumulated water in the excavated old lanes and holes, which is called old empty water. Old empty water is often the main cause of mine flooding accidents. Old empty water is characterized by high water pressure. Once it is dug through, it is intense and destructive.

Question 2: Introduction of coal mine water permeability: Coal mine water permeability refers to the accident caused by digging through the tunnel wall to connect the abandoned tunnel with groundwater or accumulated water when mining coal in the tunnel.

Question 3: What is a flooding incident? Permeability accident refers to the mining of coal mines in the lower layer, many of which are mined hundreds or even thousands of meters underground, and once the groundwater or underground river is infiltrated, it will be submerged. This situation belongs to a flood accident. The consequences are very serious, ranging from small economic losses to large deaths, mine scrapping and other major losses, such as the flooding accident in Wangjialing Coal Mine, a mine under construction by Xihua Shanxi Coking Coal Company.

Question 4: How to deal with coal mine seepage Once a water inrush accident occurs in a mine, the personnel at the scene of the accident should report to the dispatching room in time according to the provisions of the mine disaster prevention and treatment plan, and inform and organize the personnel in the affected area to evacuate the disaster area according to the disaster avoidance route. After receiving the accident call, the mine dispatching room should report to the mine leader and notify the rescue team and relevant departments. Set up a disaster relief headquarters to deal with disasters step by step. After the establishment of the disaster relief headquarters, it is necessary to quickly determine the nature of the flood, understand the water inrush point and influence range, find out the distribution of people before the accident, count the people evacuated from the well, and analyze the hiding place of the trapped people; According to the scale of water inrush and mine drainage capacity, technical measures of drainage, blocking and water interception are actively taken. If it is old kiln water, the water quantity is limited by the space of the old kiln body, so drainage method can be chosen to deal with water inrush; If surface water seeps into the ground, there is usually enough water supply. First, measures should be taken to intercept the surface water supply channel, and then the discharge of underground water inrush should be strengthened. Of course, the situation of underground water inrush is complicated, and one or several measures can be taken at the same time according to the specific situation. At the same time, if conditions permit, ventilation in the disaster area must be restored as soon as possible to prevent the accumulation of gas and other harmful gases and smoking accidents. After drainage, roof caving, roof caving and secondary water inrush accidents should be prevented in the process of reconnaissance and emergency rescue.

After the flood accident, people are often trapped underground. Commanders should still strive for time and speed and take effective measures to get them out of danger as soon as possible based on the principle of "saving people as the first task". After the flood accident, it is necessary to correctly judge the location where people in distress may escape, scientifically analyze whether the location has the living conditions for people, and then actively organize forces to rescue them. When the shelter is higher than the external water level, people in distress may survive. For people in these places, all possible methods (drilling holes or digging a section of roadway) should be used to transport fresh air, drinks and food to them to prolong the waiting time. When the shelter is lower than the external water level, there are two situations:

(1) When water inrush occurs, the flood can directly flood into the roadway (such as drift and downhill) located at the lower part of the water inrush point and drown them. Under normal circumstances, there will be no air in these places, so there will be no conditions for people to live. However, there have been many cases of people being rescued by hiding in these high caves.

(2) When the whole section of the lower roadway of the water inrush point is flooded, the upper single-headed roadway connected with the roadway, such as single-headed uphill, will not be completely flooded even if it is lower than the highest external water level, and there is still air. People who have taken refuge in these places have the conditions for survival. If the evacuation method is correct (calm down, drink enough water and lie down and wait for help), they can survive. 1 On May 20th, 1998, surface rainwater rushed into the underground of Bachangwusu coal mine in Zhuozishan mining area, Wuhai City, Inner Mongolia, and 13 people were trapped underground, of which1people survived after 34 days of underground disaster avoidance. Many examples like this show that after the water inrush accident, some places already have the conditions for people to survive, even if they avoid it for a long time, they will not be hopeless. For those refuge places below the external water level, it is forbidden to drill holes to prevent air from leaking from a single head, water level rising and drowning people in distress. The best way is to speed up drainage, that is, to rescue as soon as possible.

I think every mine should prepare an emergency plan for the accident.

Question 5: What's the problem with coal mine flooding? Compare the difference between drilling wells and dipping water in coal mines. Digging a well doesn't mean that there is water directly when you dig into the pool. Do you think that if you dig into an underground pool, the water will not rise directly because of the pressure? The purpose of digging a well is to free up a free space before there is groundwater. Because of pressure, water in rock mass or soil can be squeezed into the free space you dig, and it can rise slowly under pressure, and there is always a balance point, that is, at that point, the water level will not rise. However, the permeability of coal mine is an underground river or cave with great pressure. It used to be an empty space, full of confined water, and the old kiln water leaked from the goaf of Wangjialing. This water is under great pressure. It will leak before you touch it, and the working face will leak. At this time, it must stop, or it will be excavated inside. Before reaching the edge, the water will break through the rock under pressure, instantly. The general treatment is discharge. Block, pass and so on! I hope it helps you!

Question 6: What happened to the coal mine flooding accident? Hehehe, you are very talented. I heard for the first time that you want to dig a well to contact the flood accident! You are really talented! Digging a well doesn't mean that there is water directly when you dig into the pool. Do you think that if you dig into an underground pool, the water will not rise directly because of the pressure? The purpose of digging a well is to free up a free space before there is groundwater. Because of pressure, water in rock mass or soil can be squeezed into the free space you dig, and it can rise slowly under pressure, and there is always a balance point, that is, at that point, the water level will not rise. However, the permeability of coal mine is an underground river or cave with great pressure. It used to be an empty space, full of confined water, and the old kiln water leaked from the goaf of Wangjialing. This water is under great pressure. It will leak before you touch it, and the working face will leak. At this time, it must stop, or it will be excavated inside. Before reaching the edge, the water will break through the rock under pressure, instantly. The general treatment is discharge. Block, pass and so on! I hope it helps you!

Question 7: What are the signs when the mine is flooded? There are usually some signs before the coal seam or rock stratum is submerged. All underground workers should be familiar with the omen before the flooding accident so as to take preventive measures in time. The omen before water seepage is often: (1) The coal seam is wet and dark. Due to the infiltration of water, the coal seam becomes wet and its luster becomes dim. If the first floor is still like this, it means there is water nearby. (2) "Hanging sweat" on the roadway wall or roof is a phenomenon that water condenses on the surface of rock (coal) wall when it passes through tiny cracks in rock. (3) The coal seam becomes cold. When the coal seam contains water, it can absorb the heat of human body, and it will feel cold when touched by hand, and the longer the hand is placed, the colder it will feel. (4) The roof of the working face is drenched with water or has water head. (5) The working face temperature decreases. You can see a faint mist on the working face, which makes people feel cool. (6) water is called. Water squeezes out of cracks in coal seams, making a hissing sound, and sometimes you can hear sounds like deep thunder or boiling water, all of which are dangerous signs of water infiltration. (7) The harmful gas in the working face increases. Due to the gas escaping from the stagnant water area, the content of carbon dioxide, hydrogen sulfide and other gases in the air of the working face increased obviously. (8) Coal wall or roadway wall "hangs red". For example, old empty water usually accumulates for a long time and has little water supply, so it is usually called "stagnant water", so its acidity is high and it contains iron-containing oxides or sulfide minerals, which is a sign of approaching the accumulation of old empty water. Not all the above symptoms will appear before each immersion, sometimes one or more of them may be found, and in rare cases, they may not even appear. Therefore, we must be vigilant, closely observe and carefully analyze. This is of great significance for taking timely measures to prevent and avoid disasters.

Question 8: Where did the coal mine get so much water? Water flows downwards, because the geological conditions are not proved or the coal pillar size is not enough or is mistakenly penetrated, a large amount of water is stored in the cavity after long-term underground mining, which is equivalent to a large underground reservoir. ...

Question 9: Why must the water in the coal mine be drained before the rescue can be carried out? Hehe, brother, the underground geological conditions are different and the mining roadway is changeable. Moreover, generally permeable mines must not be explored and drained according to regulations, and most of them are small and medium-sized coal mines. So first, the conditions are not allowed, and the ingot is to avoid increasing the casualties of rescuers for no reason.