Regulations on Water Prevention and Control in Coal Mines (II)

Section 3 Underground Hydrogeological Observation

Twenty-sixth of the newly dug shaft, the main cross-layer shek mun and the development of roadway, should be timely hydrogeological observation and logging, and draw the measured hydrogeological profile or shaft, shek mun and the development of roadway map.

When the mine passes through the aquifer, its occurrence, thickness, lithology, structure, development and filling of cracks or karst should be described in detail, and the location and elevation of dew point, water outlet form, water inflow and water temperature should be revealed, and water samples should be taken for water quality analysis.

If the aquifer is fractured, its occurrence, length, width, quantity, shape, pinch-out, filling degree and filler should be determined, the trace of groundwater activity should be observed, the fracture rose map should be drawn, and the rock fracture rate in the representative area should be determined. Measured area: dense cracks, preferably1-2m2; Sparse cracks, preferably 4- 10 m2. Its calculation formula is

Where KT-fracture rate,%;

A—— measured area, m2;

L- crack length, m;

B- crack width, m.

In case of karst, we should observe its shape, development, distribution, whether there are fillings, fillings and water filling, and draw a schematic diagram of karst.

When encountering a fault structure, we should measure the fault distance, the occurrence and width of the fault zone, and observe the composition, cementation degree and water conductivity of the filling in the fault zone.

If wrinkles appear, their shape, appearance and damage should be observed.

In case of collapse column, we should observe the lithology and occurrence of strata inside and outside the collapse column, the development degree of cracks, karst and water inrush, determine the development height of collapse column, and prepare cards, attached drawings, profiles and sketches.

In case of water inrush point, time, place, exact location, water level, lithology, thickness, water outlet form, surrounding rock damage, etc. Water inrush should be observed and recorded in detail, and the water inflow, water temperature, water quality and sand content should be determined. At the same time, it is necessary to observe the water inflow and water level changes of nearby outlets and observation wells, and analyze the causes of water inrush. The main water inrush points can be systematically observed as dynamic observation points, and cards should be compiled with floor plans and sketches.

For large and medium-sized coal mines with water inflow of more than 300 m3/h, small coal mines with water inflow of more than 60 m3/h, or mining areas and mines flooded by water inrush, the water inrush situation shall be reported to the local coal mine safety supervision institutions and the departments responsible for the supervision and management of coal mine safety production and the coal industry management departments in a timely manner.

According to the water inflow per hour, water inrush points are divided into four grades: small water inrush point, medium water inrush point, large water inrush point and extra-large water inrush point:

(1) Small water inrush point: Q? 60 cubic meters/hour;

(2) Medium water inrush point: 60 m3/h

(3) Large water inrush point: 600 m3/h

(4) Extraordinary water inrush point: Q> 1800 m3/hour.

Twenty-seventh mines should strengthen the observation of mine water inflow and water quality monitoring.

The mine should be divided into wells and levels to set up observation stations to observe the water inflow, and the number of observations should be no less than 3 times a month. For the fractured zone and collapse column with large water inflow, a separate observation station should be set up for observation, and the observation frequency is 1-3 times a month. Water quality monitoring shall be carried out at least twice a year, in wet season and dry season 1 time respectively. In the rainy season when the water inflow is abnormal, water inrush occurs underground or the mine is affected by precipitation, the observation frequency should be appropriately increased.

For the newly exposed underground outlet, before the water inflow has not stabilized or mastered its changing law, it should generally be observed 1 time every day. For water inrush, before the cause of water inrush is found out, it should be observed every 1-2 h, and the observation frequency is 1 time. In the future, the observation interval can be appropriately extended, and water samples should be taken for water quality analysis. After the water inflow is stable, it can be observed according to the normal observation time underground.

When there is a surface water body, a water-rich aquifer, a structural fault zone connected with the water-rich aquifer, or near the goaf water accumulation area within the influence range above the mining face, it is necessary to observe the water inrush situation every day and master the change of water quantity. See Appendix II for the water abundance grade standard of aquifer.

For newly drilled vertical shafts and inclined shafts, the water inflow of 1 time should be observed for every extension of vertical depth of 1 0 m. When driving into a new aquifer, if the distance is less than the specified distance, the water inflow of1time should be measured on the top and bottom plates of the aquifer.

When observing mine water inflow, we should pay attention to the continuity and accuracy of observation, and adopt volume method, weir method, buoy method, current meter method or other advanced water measurement methods. Measuring tools and instruments should be calibrated regularly to reduce human error.

Article 28 When the underground aquifer is drained and depressurized, the water inflow and water pressure of 1-2 borehole should be observed every hour before the water inflow and water pressure are stable; After the water inflow and water pressure are basically stable, it shall be carried out according to the requirements of normal observation. The discharge of old empty water should be observed every day.

Section IV Hydrogeological Supplementary Exploration

Twenty-ninth mine in any of the following circumstances, should carry out hydrogeological supplementary exploration work:

(a) the main exploration target layer of the mine has not carried out hydrogeological exploration work;

(two) the original exploration of the mine is insufficient, and the hydrogeological conditions have not been ascertained;

(three) after the coal seam is exposed by mine mining, the hydrogeological conditions are more complicated than the original exploration report;

(four) after long-term mining, the hydrogeological conditions have changed greatly, and the original exploration report can not meet the production requirements;

(five) mine development and deepening, mining new coal measures (groups) or expanding the scope of mine design needs;

(6) The roof of mine roadway is located in special geological conditions under deep coal seam or in strong water-filled aquifer, and the floor of coal seam is under pressure, which puts forward special requirements for special water prevention and control projects;

(seven) all kinds of mine engineering through strong water-rich aquifer, construction needs.

Thirtieth the layout of hydrogeological supplementary exploration quantities should meet the corresponding degree of work and meet the requirements of water prevention and control work.

When carrying out supplementary hydrogeological exploration in mines, the regional groundwater system including the exploration mining area should be analyzed and studied as a whole; In areas outside the mine field, it should be based on hydrogeological surveying and mapping; Within the scope of the mine field, hydrogeological geophysical prospecting, drilling and water pumping (drainage) test should be the main methods.

Supplementary exploration of mine hydrogeology should be based on the types and specific conditions of mine hydrogeology, comprehensively using various exploration technologies such as supplementary investigation of hydrogeology, geophysical exploration, hydrogeological drilling, water pumping (drainage) test, hydrochemistry and isotope analysis, dynamic observation of groundwater, sampling and testing, and actively adopting new technologies and methods.

Supplementary exploration design of mine hydrogeology should be compiled and implemented after being audited by the chief engineer of coal mine enterprise. Supplementary exploration design should be based on sufficient, purposeful and targeted engineering layout, make full use of the existing conditions of the mine, and achieve the combination of ground and underground.

After the completion of hydrogeological supplementary exploration, the results report or data shall be submitted in time, and the chief engineer of the coal mining enterprise shall organize the acceptance.

Section 5 Supplementary Exploration of Surface Hydrogeology

Article 31 When carrying out hydrogeological drilling in a mine, each borehole should be designed as a single hole according to the requirements of exploration and design, including the borehole structure, borehole inclination, core recovery rate, requirements for hole sealing and water stopping, final aperture, final horizon, simple hydrological observation, pumping test, geophysical logging and sampling test, hole sealing quality, orifice device and measurement mark requirements.

The main technical indicators of drilling construction shall meet the following requirements:

(a) the final hole depth of mine hydrogeological supplementary exploration drilling mainly based on water inrush from coal seam floor;

(2) All exploration boreholes shall be recorded in hydrogeology. If conditions permit, flow logging, ultrasonic imaging and borehole TV detection can be used. The water layer and water-resisting layer can be divided by drilling and coring, which provides the basis for obtaining relevant parameters;

(3) The main aquifer or test section (observation section) is drilled with clean water. When it is necessary to switch to mud drilling under special circumstances, with the consent of the geological department of the drilling construction unit, low-solid high-quality mud can be used and effective well washing measures can be taken;

(4) The drilling diameter is determined according to the purpose of drilling. The diameter of the test section of the pumping test hole is based on the principle of meeting the design pumping capacity and installing pumping equipment; The aperture of the observation section of the water level observation well should meet the requirements of water stop and water level observation;

(five) the hole inclination of the pumping test hole meets the technological requirements for selecting pumping equipment and water level observation instruments;

(6) Core for drilling and core description. Core recovery rate: the rock is more than 70%; The fracture zone is greater than 50%; More than 70% clay; Sandstone layer is greater than 30%. When the position and thickness of stratum and water-bearing (barrier) layer can be correctly divided by hydrogeological logging, coring can be appropriately reduced;

(7) Separate and seal water in the borehole by layers (sections), check the sealing effect by different methods such as water lifting, water injection and hydrogeological logging, and make official records; Unqualified, stop water supply;

(8) Except for long-term dynamic observation drilling, other drilling holes are sealed with high-grade cement slurry, and the sealing quality is sampled and inspected;

(9) After the completion of the observation well, pump water and punch holes to ensure that the observation layer (section) is not silted.

Hydrogeological drilling should carry out simple hydrogeological observation, and its technical requirements should be implemented with reference to relevant regulations and norms. For drilling holes without simple hydrogeological observation data, the quality level should be lowered or not accepted.

Hydrogeological observation wells should be equipped with orifice devices and long-term observation and measurement marks, and effective measures should be taken to protect them to ensure durability and convenient observation; If it is damaged or blocked, it should be handled in time.

Thirty-second production mine hydrogeological supplementary exploration pumping test quality, shall comply with the provisions of the relevant national standards and industry standards.

The drawdown of water level in pumping test should reach the maximum drawdown according to the equipment capacity, and the drawdown times should be no less than 3 times, and the drawdown distance should be reasonably distributed. When the drilling water level affected by mining is deep, only the maximum drawdown 1 pumping test can be done. In the observation of the depth lowering process, the requirements of unsteady flow calculation should be considered and the time should be extended appropriately.

For the mine with complicated hydrogeology or extremely complicated mine, if the hydrogeological and engineering geological conditions (ground karst collapse) cannot be ascertained by using small-caliber pumping, the underground drainage test can be carried out; If the underground conditions are not available, a large-diameter and large-flow group hole pumping test should be carried out. The group hole pumping test should be designed separately and implemented after being examined and approved by the chief engineer of the coal mine enterprise.

The duration of large-diameter porous pumping test should be determined according to the water level stability trend and the flow process curve, which is generally not less than 10 day; When the water level is unstable due to the interference of mining drainage, it should be determined according to the specific situation.

In order to find out whether there is hydraulic connection between the aquifer affected by mining damage and other aquifers or surface water bodies, the connection (tracing) test can be carried out in combination with pumping (drainage) water.

Before pumping, the water level (pressure) and flow should be observed in test holes, observation wells and relevant hydrogeological points above and below the well. When necessary, special drilling holes can be constructed to measure the central water level of large-diameter group holes.

Article 33 In order to study the permeability of rocks, if it is impossible to conduct pumping test due to mine seepage prevention or deep aquifer water level, water injection test can be conducted.

Water injection test should be designed. The test design includes the starting and ending depth of the test interval; Aperture and casing running horizon, depth and water stopping method; Water injection equipment, water injection test method and water injection test quality requirements adopted.

The main technical indicators of water injection test construction shall meet the following requirements:

(a) according to the rock lithology and the development depth of pores and fractures, determine the test hole section and strictly do a good job of water stop;

(2) Before the water injection test, thoroughly wash the well to ensure the aquifer dredging, and measure the borehole water temperature and the injected water temperature;

(3) Water injection test shall be conducted before and after formal water injection, and static water level and recovery water level shall be observed.

Article 34 The layout of geophysical prospecting work, determination of parameters, number of measuring points, repeated measurement errors, data processing, etc. It shall comply with the provisions of relevant national standards and industry standards.

Before geophysical exploration, the exploration scheme should be determined according to the hydrogeological conditions of the exploration area, the geophysical characteristics of the detected geological body and different working purposes. In geophysical exploration, various geophysical methods can be used for comprehensive exploration.

After geophysical exploration, the corresponding comprehensive result map shall be submitted. Geophysical prospecting results should be combined with other exploration results, and after mutual verification, they should be used as the basis for mine mining design.

Section 6 Underground Hydrogeological Exploration

Article 35 Underground hydrogeological exploration shall comply with the following provisions:

(a) the use of underground geophysical prospecting, drilling, monitoring, testing and other means;

(2) Adopt a comprehensive exploration method combining underground and surface;

(three) to ensure the safety of mine production, and to take reliable safety measures in underground exploration and construction.

Thirty-sixth mine in any of the following circumstances, should be carried out underground hydrogeological exploration:

(a) it is difficult to find out the problems in the surface hydrogeological exploration, and it is necessary to carry out drainage test or connectivity (tracer) test underground;

(two) there are water-bearing (flowing) sand layers or karst aquifers on the roof and floor of the coal seam, and it is necessary to carry out hydrophobic mining tests;

(three) due to the limitation of surface water and topography or the influence of mining subsidence, the ground does not have the construction conditions;

(four) the depth of the borehole or the buried depth of the groundwater level is too large to carry out hydrogeological tests on the ground.

Article 37 Underground hydrogeological exploration shall meet the following requirements:

(a) the technical requirements of drilling, safety measures and other drilling construction design shall be implemented after the approval of the chief engineer of the mine;

(2) Build and reinforce the rig cabin to ensure normal working conditions;

(3) The rig is firmly installed. First, lay orifice pipe and conduct pressure test. Before the formal construction, install the orifice safety gate valve to ensure the control of water displacement. The compressive capacity of the safety gate valve is greater than the maximum water pressure. Install orifice blowout preventer before exposing aquifer;

(four) according to the design of construction, and strictly implement the construction safety measures;

(five) connectivity test, shall not choose the tracer of water pollution;

(six) to stop using or scrapped drilling, timely plugging, and submit the report of hole sealing.

Thirty-eighth water discharge test shall follow the following principles:

(a) the preparation of water test design, determine the test method, the depth reduction value and water discharge. The displacement is determined according to the existing maximum drainage capacity of the mine. In principle, observation wells that can be affected by water discharge test should have obvious water level drop. Its design is examined and approved by the chief engineer of the coal mining enterprise;

(2) Make preparations before water discharge test, assign personnel, check and correct observation instruments and tools, and check the capacity of drainage equipment and drainage lines;

(3) Before discharging water, the water level, water pressure, water inflow, water temperature and water quality of the observation well and the well outlet should be measured at the same time;

(four) according to the specific situation to determine the duration of water testing. When the water inflow and water level are difficult to stabilize, the test duration is generally not less than 10- 15 days. When choosing the observation interval, the need of unsteady flow calculation should be considered. Synchronous observation of central water level or water pressure and water inflow;

(5) The observation data shall be recorded in the ledger in time, and the water inflow-water level duration curve shall be drawn;

(six) after the water discharge test, timely sort out the data and submit the summary report of the water discharge test.

Thirty-ninth for the mine threatened by water disasters, when it is difficult to carry out mining evaluation by conventional hydrogeological exploration methods, cross-layer stone gates or special sinking shafts can be used to carry out drainage and depressurization mining tests according to conditions.

Hydrophobic depressurization mining test shall meet the following requirements:

(a) there is a special construction design, and its design is examined and approved by the chief engineer of the coal mining enterprise;

(2) The estimated maximum water inflow;

(three) to establish a drainage system that can ensure the maximum water inflow;

(four) choose the appropriate location to build waterproof gate;

(five) to do a good job in drilling advanced water exploration and water decompression;

(six) do a good job in the observation of water level, water pressure and water inflow.

Article 40 Mines may adopt geophysical methods such as direct current method (resistivity method), audio frequency electric perspective method, transient electromagnetic method, electromagnetic frequency sounding method, radio wave perspective method, geological radar method, shallow seismic exploration, Rayleigh wave exploration and trough wave seismic exploration according to the actual situation of their own units. Combined with drilling method to verify the data.

Chapter IV Mine Water Prevention and Control

Section 1 Prevention and Control of Groundwater

Forty-first mines should find out the catchment, leakage and drainage capacity of the surface water flow system in the mining area and its vicinity and related water conservancy projects; Understand the local reservoirs, hydropower dams, river embankments, rivers and obstacles in rivers; Master the data of local precipitation and maximum flood level over the years, and establish drainage, waterproof and drainage systems.

Forty-second mine wellhead and industrial site building elevation should be higher than the local maximum flood level over the years.

If you are in mountainous areas, you should not only abide by the provisions of the first paragraph of this article, but also avoid areas where mudslides and landslides may occur.

Where the elevation of buildings at mine wellhead and industrial site is lower than the highest flood level in local history, dams, ditches or other waterproof and drainage measures shall be built.

Forty-third when the surface water near the mine wellhead or inside and outside the subsidence area may collapse underground, safety precautions should be taken.

It is forbidden to mine the waterproof coal (rock) pillar of coal seam outcrop.

In places where water is easy to accumulate on the surface, ditches should be built to drain the water. When building ditches, outcrops, cracks and water-conducting rocks should be avoided. If ditches cannot be built for drainage in particularly low-lying areas, they should be filled and compacted. If the low-lying area is too large to be filled in at ordinary times, it is necessary to use a water pump or a flood discharge station for special drainage to prevent the water in the low-lying area from infiltrating into the ground.

When the mine is threatened by rivers and mountain torrents, dams and flood discharge canals should be built to prevent flood invasion.

Mine water discharged to the ground should be properly treated to avoid infiltration into the ground.

Leaking ditches (including irrigation ditches) and river beds should be blocked or diverted in time. Ground cracks and collapses should be filled in time. When filling, corresponding safety measures should be taken to prevent people from falling into the collapse pit.

In areas where landslides are dangerous and may threaten the safety of coal mines, landslide prevention measures should be taken.

Article 44 It is strictly forbidden to pile up gangue, furnace ash, garbage and other sundries in areas where mountain torrents and rivers may scour, so as to avoid damaging industrial sites and buildings or blocking rivers and ditches.

Article 45 For drilling holes in use, orifice covers shall be installed as required. For scrapped drilling holes, the holes should be sealed in time to prevent surface water or aquifer water from flowing into the ground. For observation wells, grouting holes, cable holes and boreholes communicating with underground or aquifer, the orifice pipes shall be higher than the local maximum flood level.

Forty-sixth scrapped vertical shaft should be sealed, or 1 solid reinforced concrete cover plate larger than the well section should be poured at the wellhead, and fences and signs should be set up.

Scrapped inclined shafts shall be filled and sealed, or the inclined long masonry 1 brick, stone or concrete wall 20 m below the wellhead shall be filled with soil and sealed with masonry.

Abandoned adits should be filled at least 20 meters away from the adit mouth, and then closed by building walls. If there is surface water around the abandoned wellhead, a drainage ditch should be set up.

When the abandoned vertical shaft, inclined shaft and adit are closed, the concealed works should be recorded and the drawings should be filled in for filing.

Article 47 Mines should contact meteorological, water conservancy, flood control and other departments to establish a mechanism for early warning and prevention of disastrous weather. Coal mines should timely grasp the information of rainstorm and flood disasters that may endanger the safety production of coal mines, and pay close attention to the forecast and early warning information of disastrous weather; Grasp the water situation in time and take safety precautions; Strengthen information communication with neighboring mines, and immediately warn neighboring mines if abnormal conditions are found in the mine.

Article 48 A mine shall assign a special person to patrol and inspect abandoned old kilns, ground subsidence pits, mining cracks, reservoirs, lakes, rivers, culverts, dikes and other key parts that may affect mine safety production. After receiving the rainstorm disaster warning information and alarm, it should be inspected 24 hours a day. Before and after every rainstorm in the mining area, professionals should be sent to observe the change of mine water inflow in time.

Forty-ninth mines should establish a system of timely evacuation of underground personnel in case of disasters such as storms and floods, and clarify the starting standards, command departments, liaison personnel and evacuation procedures. When it is found that serious rainstorm and flood disasters may cause the well to be flooded, the operators should immediately evacuate to a safe place. Production can only be resumed after the hidden dangers are completely eliminated.

Fiftieth mine before the rainy season, should comprehensively check the implementation of preventive measures, to prevent accidents caused by heavy rain and flood. For the hidden dangers of accidents found out, it is necessary to implement the responsibility and complete the rectification before the flood season. The water prevention project shall be specially designed, and the chief engineer of the mine shall be responsible for organizing the acceptance after the project is completed.

Section 2 Design of Waterproof Coal (Rock) Column

Fifty-first adjacent mine boundary, should leave waterproof coal (rock) column. If a mine is divided by a fault, waterproof coal (rock) pillars shall be left on both sides of the fault.

Fifty-second mines threatened by water disasters shall be reinforced with waterproof coal (rock) columns under any of the following circumstances:

(a) the outcrop weathering zone of coal seam;

(2) Under surface water bodies, water-bearing alluvium and adjacent submerged areas;

(3) Coal seams in contact with faults, fracture zones or strong water-conducting faults of strong water-rich aquifers;

(four) there are a lot of water in the old kiln and goaf;

(five) water, water-filled collapse column, cave or underground river;

(6) Dividing mining boundaries by region;

(7) Protected observation wells, grouting holes and cable holes, etc.

Article 53 A mine shall determine the corresponding waterproof coal (rock) pillar size according to the geological structure, hydrogeological conditions, coal seam occurrence conditions, physical and mechanical properties of surrounding rocks, mining methods and strata movement laws of the mine. See Appendix III for the dimension requirements of waterproof coal (rock) columns.

Mine waterproof coal (rock) column should be specially designed by mine geological survey institutions, and implemented after being reviewed and approved by the relevant units organized by the chief engineer of the mine.

Fifty-fourth mine waterproof coal (rock) column once determined, shall not be arbitrarily changed. Mining activities in various waterproof coal (rock) pillars are strictly prohibited.

Article 55 When mining abandoned waterproof coal (rock) pillars under flooded areas, the accumulated water in the upper part shall be drained. Top water operation is strictly prohibited.

Fifty-sixth mines with a history of water inrush or mining under pressure shall be isolated horizontally or in different mining areas. Before zoning, waterproof coal (rock) columns should be reserved and waterproof gates should be set up to control water potential, reduce disasters and ensure mine safety when water inrush occurs.

Section 3 Drainage System

Fifty-seventh mines should be equipped with pumps, drainage pipes, power distribution equipment and water warehouses that match the mine water inflow to ensure the normal drainage of mines.

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