1) Measures to prevent surface water damage
1. Leave a waterproof coal pillar. Above the mine, there are rivers, rivers, lakes, seas, reservoirs, etc., which are harmful to the mine, have the possibility of seeping through water, and can not be drained. Waterproof coal pillars can be left.
2. Rivers and ditches are diverted. Rivers and ditches are pressed against the outcrop parts of coal seams and rock formations, and a large amount of water leaks into the underground. The threat of water permeability to mining can be diverted to rivers and ditches. When the river leaks into the well, it can also take measures to prevent the leakage of the bed.
3. The water is drained. For the water in the collapse pit, the water in the pond, etc., as long as there is the possibility of water inrush, the water must be drained to produce, and the water in the area should be regularly viewed during the production process. In particular, there is a funnel-shaped collapse pit in the coal face of the steeply inclined coal seam, and the threat of water seepage is greater. Therefore, when mining steeply coal seams, it is necessary to lower the upper limit of mining and leave a waterproof coal pillar to ensure safety.
4. Hydraulic filling. The coal mining face does not need to be controlled by the slump method, but the water sand is used to infuse the goaf, support the roof of the goaf, reduce the amount of subsidence, reduce the impact on the surface subsidence, and avoid the flow of water into the well.
5. Raise the wellhead elevation of the main, auxiliary and wind shafts. In order to ensure the safety of the rainy season, it is necessary to investigate the impact of the highest flood level and flash floods around the mine and raise the wellhead elevation of the main, auxiliary and wind shafts.
2) Measures to prevent and control underground water damage
Underground water damage includes old kiln water, water in goaf, old roadway water, borehole water, fault water, subsided column water, limestone cave water, sandstone water, conglomerate water, alluvial water and so on.
1. Prevention and control of old kiln water
A. Establish an organization to check the situation of the old kiln.
B. Inquire about the old comrades who worked in the old kiln to find out the mining years, the location of the coal seams, the mining distance and depth, and the amount of water inflow.
C. Find drawings and materials of existing kiln. After careful analysis and judgment, formulate plans for the prevention and control of old kiln water, and implement them conscientiously.
D. In the case of unclear circumstances, adhere to the principle of “doubt must be explored†to advance forward. When you hit the front of the rhinestone, if there is a sign of permeable water, you can't get the drill. You should report it as soon as possible and deal with the danger.
Install water pumps and drain lines when exploring water, and establish a water tank to ensure that production will not affect the production or cause an accident if the water is detected.
Special attention is paid to the fact that if the old kiln water is the mined water formed by the mining of the upper coal, and the newly opened mine or the new mining area is the mined coal, the coal mining with the old kiln water is always available. The possibility of a water inrush accident. Therefore, the top water mining is prohibited until the water in the upper coal mined area is not drained.
2. Prevention and control of water accumulated in mine goaf and water accumulation in old roadway
There is bound to be water in the goaf of the mine and the old roadway. The prevention and control work requires the measurement department to measure the mapping in a timely and accurate manner, and it should not be missed. When the excavation working face is close to the goaf and the old roadway, it must be explored first. When mining coal face mining, there is a threat to production, and it is necessary to drill and drain the water. When digging the working face, it is necessary to excavate the old roadway, and then the old roadway must be drained before the old roadway can be dug.
3, drilling water prevention
Although the borehole is small, the water can be flooded but it can flood the well. The prevention and control measures for the drilling water hazard are: first check the position of the drilling plane is where the mining working surface is, and then check the sealing quality of the drilling hole. If the hole penetrates the water-rich layer, the sealing quality is not good. To ensure safety, the professional team should be re-sealed with the rig . In addition, you can also protect the coal pillar to protect the borehole.
4. Prevention and treatment of fault water
Faults are divided into permeable faults and impervious faults. The measures to prevent fault water are: consult the geological report or hydrogeological report, and the larger fault can be detected as a water-permeable fault or an impervious fault. If the fault is rich in water, the method of leaving the fault waterproof coal pillar can be used to prevent the water leakage accident of the fault layer. When the fault location is unclear and it is not known whether it is a water-permeable fault or an impervious fault, underground drilling can be used to find out the fault location and the water permeability of the fault plane. If the fault is rich in water and connected with the Ordovician limestone or connected with other thick layered limestone caves and water-bearing sandstones, the fault layer is large and difficult to be drained. It is better to leave a fault waterproof coal pillar to protect the fault. When drilling the ground with a method of drilling, establish a drainage base in advance. Mining under the reverse fault, the upper plate of the fault is pressed above the coal seam, leaving a fault waterproof coal pillar.
5. Prevention and control of subsided column water
The collapse column refers to the thick and soluble rock mass buried in the lower part of the coal-bearing strata. Under the action of groundwater dissolution, a huge karst cavity is formed. The overlying rock mass falls down under the action of gravity and is filled in the cave. The form is A cylinder, so called a karst collapse column. The collapse column is divided into two types according to its water-filling characteristics: water-contracting column and non-water-containing column. The water guiding collapse column is large and stable, which is easy to cause flooding accidents.
The measures to prevent the collapse of the column water are: to find out the location of the collapse column according to the geological data, and use the underground drilling method to find out whether the collapse column is water-conducting. If the water volume is not good, it can be left with a collapse column waterproof coal pillar; Small, can be used to ensure the safety of mining.
6. Prevention and control of limestone cave water
After the limestone is dissolved by water, the resulting void is called karst. The water present in the karst is called karst water. The karst has various forms, ranging in size from small to solvent-soluble, to caves, and the caves can become dark rivers.
Measures to prevent karst water: The outcrop part of limestone is located below the surface river, and the underground karst water is replenished by the ground river. In order to cut off the source of karst water supply, the river can be used to prevent water leakage or river diversion. Ground drilling can also be done by cement grouting to block water.
For mining safety, the method of depressurization and dewatering can be adopted: the roadway and the borehole are generally used to drain the karst water. When draining, the water gates are established at appropriate positions in the well to ensure that the divisions, sub-separation zones, horizontal separation, and hydrophobicity are produced correctly with other regions.
When the limestone cave water is too large and connected with the Ordovician limestone, it may be ineffective to take the blockage. It is necessary to carefully consider whether to continue mining.
7. Prevention and control of sandstone water and conglomerate water
Most of the sandstone and conglomerate are located in the roof and bottom of the coal seam. The sandstone is dense and non-porous on the surface, and the actual water content is not small, and it is rich in fissure water. Therefore, when the roof has thick layered sandstone, the rig should be used to explore the water before the working face is recovered. When there is water, the roof sandstone water must be drained before mining, and the method of dredging can be done with a drilling machine. Before the mining of the steeply inclined coal seam, the sandstone water in the bottom plate should be drained to prevent the water in the goaf from causing water inrush.
8. Prevention and control of alluvium water
Alluvial water is commonly referred to as shallow surface water, and there are flowing sand, mortar, mud, etc. in the layer. To control alluvial water, the upper limit of mine production should be correctly determined. The upper limit of mining is to ensure that alluvial water and surface water cannot flow downhole. In some areas, small coal mines are indiscriminately excavated, specializing in outcrop coal, and some coal pillars above the upper limit of large mining mines often pose a threat to the safe production of large mines.
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