Flood prevention technology in the hottest mines

Mine flood prevention technology

ground water prevention and drainage refers to various water prevention and drainage technical measures taken to prevent atmospheric precipitation and surface water from replenishing the aquifer in the mining area or directly mixing into the underground of the well

it is the first line of defense to reduce mine water inflow and ensure mine safety production. It mainly includes digging ditches to drain (intercept) flood, anti-seepage of the ground in the mining area, waterproof dikes and river regulation

1. Ditch drainage (flood interception)

in the mining area located at the foothill and piedmont plain, if there is atmospheric precipitation flowing into the open pit, deposit drainage collapse area, pit mining collapse area, industrial square and other low depressions along the slope, causing local areas to be flooded, or along the water filled rock outcrop area, structural fracture zone and even the wellhead to infiltrate (irrigate) underground, ditches must be built above the mining area, perpendicular to the incoming water direction, to intercept the mountain torrents. Flood drainage (intercepting) ditches are usually arranged along the topographic contour line, and the water is discharged out of the mining area according to a certain slope

2. The ground seepage prevention in the mining area

the outcrop area of the aquifer in the mining area, the drainage collapse area, the cracking or subsidence area caused by mining, the old kiln and the unsealed drill hole are located in the catchment and ponding area of the ground. The composite polyurethane adhesive is used as a new high molecular material, and serious leakage will occur, which will pose a threat to the safety of the mine. The pond leakage in the mining area is serious, which is unfavorable to the safety of the mine or the stability of the open pit slope, so the ground anti-seepage measures should be taken

anti seepage measures mainly include:

(1) for sections with leakage but no collapse, clay or loam can be used to cover and tamp, with a thickness of 0.5 ~ 1m, taking no leakage as the degree

(2) for water filled channels such as large collapse pits and cracks, the lower part is usually filled with block stones, and the upper part is tamped with clay, which is about 0.3m higher than the ground, so as to prevent re sinking and ponding after natural compaction

(3) for the opening collapse (karst cave, wide crack) with bedrock exposed at the bottom, the support (such as waste steel rail, waste steel pipe, etc.) should be laid at the bottom of the hole first, and then the hole should be sealed with concrete or reinforced concrete, and then Earth rock should be backfilled on it. When backfilling near the ground, use 0.8m clay to tamp in layers and make it about 0.3m higher than the ground

(4) when it is difficult to fill up some large-scale low-lying areas in the mining area, it can be considered to set up a mobile pump station in the appropriate part until the illumination polygon aperture ring can just fill the field of vision and remove water, so as to prevent waterlogging. For large surface water bodies in the mining area, try to cut off the source and drain as much as possible, and prevent seepage and plugging, so as to reduce the infiltration of surface water

3. Build waterproof dikes

when the wellhead of the mining area is lower than the local historical highest flood level or the main water filled rock stratum of the mining area is buried near the river, and the water resisting layer is under the riverbed, dikes should be built to intercept the river

4. river regulation

when there is a river passing through or near the mining area, and the leakage is serious, threatening the mine production, measures should be taken to regulate the river. The anti-seepage measures of the river include: anti-seepage blanket; Impervious aqueduct; River channel straightening; River diversion

II. Underground waterproof

mining activities will always directly or indirectly damage the aquifer, causing groundwater to flow into the pit. In this sense, pit water filling is inevitable. However, it is not only possible but also necessary to prevent water inrush in the pit and minimize the water inflow in the pit to ensure the normal production of the mine. Underground waterproofing is a technical measure taken for this purpose. According to the hydrogeological conditions of the deposit and the requirements of mining work, the underground waterproof measures are also different. Such as water exploration and drainage in advance; Reserve waterproof pillars; Building waterproof facilities and grouting water plugging

1. Advance water exploration and drainage

it refers to the underground waterproof measures taken to eliminate hidden dangers and ensure safety when constructing shafts and roadways in sections with complex hydrogeological conditions, drilling in the pit before tunneling to find out the water situation in front of the work

"if there is any doubt, explore first and then excavate" is the management principle that must be adhered to in the mining construction. Generally, advance water exploration must be carried out when encountering the following situations:

(1) when the excavation work is faced with parts near old kilns, old goafs, underground rivers, quicksand layers, flooded wells, etc.;

Special broaching machine for impact sample notch is used to process samples for experiments (2) when the roadway is close to water rich faults;

(3) When the roadway is close to or needs to pass through the strong aquifer (zone)

(4) when the roadway is close to the isolated or suspended groundwater prediction area

(5) there are obvious signs of water outflow such as fog, sweating, dripping, drenching, spraying, and water ringing on the heading face

(6) when the roadway is close to the unconsolidated tailings filling goaf, unsealed or poorly sealed water diversion boreholes

2. reserve waterproof ore (rock) pillars

in the section where the ore body contacts with the aquifer (zone), in order to prevent water inrush hazards in the shaft or goaf space, reserve a certain width (or height) of steel wire rope horizontal tensile testing machine. Adopt our company's mature universal testing machine technology. The ore (rock) body is not mined to block the water from flowing into the mine. This part of the ore body is called waterproof ore (rock) pillars (hereinafter referred to as ore pillars). Generally, waterproof pillars should be considered under the following circumstances:

(1) when the ore body is buried under the surface water body and loose pore aquifer, and other water control measures are not economical, waterproof pillars should be reserved to ensure that the mining fissures of the ore body do not affect the surface water body or overlying aquifer

(2) when the ore body is covered with a strong aquifer, waterproof pillars should be reserved to avoid water inrush caused by mining damage

(3) when the ore body is in direct contact with the strong aquifer due to faulting, waterproof pillars should be reserved to prevent groundwater from collapsing into the shaft and roadway

(4) when the ore body contacts with the water diversion fault, waterproof pillars should be reserved to prevent groundwater from flowing into the shaft along the fault

(5) when there is a high head confined aquifer in the floor and there is a danger of floor breakthrough in the shaft and roadway, waterproof pillars should be reserved to prevent water inrush in the shaft and roadway

(6) when the mining face is adjacent to the ponding old kiln and flooded shaft, waterproof pillars should be reserved to prevent the water from entering the shaft