The Water-disaster Characteristic of Coal Mine in Shandong Province and the Research on Prevention and Control Countermeasures Zhang Wenquan1, 2, Ren Zhongping3, Jiang Hua3, Sun Gaoliang3, Hang Qianqian3, Dong Yi1, 2 (1.College of Mining and Safety Engineering, Shandong University of Science and Technology, Qingdao, Shandong 266590 2.National Key Laboratory of Mine Disaster Prevention and Control (Cultivation Base), Qingdao 266590 3.Administration of Coal Industry in Shandong Province, Jinan, Shandong 250031)

Abstract disaster, source, characteristic, prevention The key to prevent coal mine water and control. disaster is finding out the "three Shandong, with a long mining elements" which is separately named history, is one of the largest coal source, channel and strength. Only by resources province in our country, coal is figuring out the "three elements", can the the important basic energy in Shandong coal mine water-disaster prevention and province. Coalfield geological structure control work achieve its target. Through and hydro geological condition of analyzing the inrush source, influence Shandong are relatively complex. area and gushing channel, deeply According to the statistics, the complex understanding the current situation of and extremely complex hydrogeology coal mine water-disaster in Shandong type coal mine in Shandong province province, this article explores the basic accounted for more than 24% of all kinds characteri stics of the coal mine of registered coal mines. All kinds of water-disaster, points out the main water disasters seriously threaten the existing problems in the work of development and utilization of coal prevention and control of water-disaster. resources (figure 1, figure 2). With the Also it puts forward the countermeasures increase of mining depth and mining area, of prevention and control of the threat to mine safety production is water-disaster and its application increased, among which, the water instance. damage problem is particularly prominent. According to the statistics of Keywords: Shandong province, water Shandong coal industry bureau, among

294 the coal mine of whole province, there mine water hazards happen from time to are 25 mines threatened by the surface time in Shandong province, prevention water disaster, 29 mines threatened by the and control of basic water management is old empty water disasters, 7 mines relatively weak, hydrogeological threatened by the overburden water conditions of mining working face should disasters, 30 mines threatened by the be find out further more, drain measures bottom pressure water disasters, 18 mines still need complements. The key to threatened by the adjacent mines and prevent coal mine water-disaster is closed mine water disasters, 6 mines with finding out the "three elements" named the upper limit of mining working face source, channel and strength. Only by increasing threatened by water disasters; figuring out the "three elements", can the 8 mines threatened by the connected coal mine water-disaster prevention and mine water disasters. In recent years, coal control work achieve its target.

Old goaf accident Aquifer accident 14.50% Surface accident

47.30%

38.20%

Fig 1: Statistics of catastrophic water accident in national key coal mines (1949~2004)

295 Old goaf accident Aquifer accident 9.70% 4.90% Surface accident

85.40%

Fig 2: Statistics of catastrophic water accident in local coal mines (1949~2004) 1.1 Water-disaster type and influenced area 1 Analysis of coal mine water-inrush 1.1.1 Water-disaster of surface and condition in Shandong province precipitation There are two sufficient conditions Surface drainage is very developing required to coal mine water inrush: the in Shandong, average density of natural water filling source and water rivers is above 0.7 km/km2, length of the channels[1]. Sources of Shandong coal trunk stream with 50 km above has more mine threatened by water disasters than 1000. Water of the surface body mainly include: surface water, goaf water, near the mine together with the top of the old gob water, Quaternary loose bed mining area develops to being disaster by water, Paleogene sandy gravel water, loose layer, surface subsidence area, Jurassic sandstone (commonly known as tectonic fracture zones, the mined areas "red layer") water, Shanxi Formation and wellhead collapsing into the roadway. sandstone water, Taiyuan Formation thin Especially when the coal seam buried limestone water, Ordovician limestone shallow, with thinner Quaternary water, etc. Water channels can be divided overburden, shallow karst developed, the into natural and artificial channels. mine is easily supplied by atmospheric precipitation and surface water, not easy

296 to drainage. When encountering heavy outcrop area or the sub crop area of rain and the flood, serious flooding wells Quaternary water.[2] Coal mines in accident happens. For example, Shandong province affected by the Longshan mine which is located in Linyi damage of Paleogene, Jurassic water are City submergenced due to floods, causing less. But it is a big threat to coal mine 59 deaths in 1993. In "8.17"accident, 172 production, especially when the location people in Huayuan mine were dead. At is in the areas with more developing present, the mining area under the threat conglomerate and rich water, or in special of surface water and precipitation of geological areas, existing small space Shandong Province mainly include: Zibo, between upper minable seam and its Zhangqiu, Tengzhou, Xinwen, etc. conglomerate water body, such as the 1.1.2 Water-disaster of Quaternary forth and sixth layer of Huafeng coal loose layer mine which is under serious threat of Such water-disasters are mainly Paleogene sandy gravel water. The distributed in the coal seam outcrop influence of such water-disasters area which is directly located in the sandstone mainly include: Baodian mine in layer under the Quaternary, with large Yanzhou coal, Huafeng mine in Xinwen thickness of the overlying coal seam and coal and Beixulou, Tianchen, Xinan mine rich water or thin layer of Quaternary in Tengzhou coal, etc. loose with unreliable wind oxidized zone 1.1.4 Water-disaster of Shanxi of waterproof coal column. Once the coal Formation sandstone seam mining fissure belt reaches to Shanxi Formation sandstone is the bottom Quaternary group, it is prone to main aquifer in Shandong Province’s coal collapse of water and sand, causing mines. Shanxi Formation sandstone is flooded surface or flooded wells whose fracture aquifer; the water is weaker degree of damage is larger. The mining overall and in homogeneity, not easy to areas which are affected by the accept supplies, usually attaching small Quaternary loose bed water mainly threat to the safety of mine production include: Linyi, Tengzhou, Jining, aside from the Xinwen, Jining, Tengzhou Zhangqiu, Taozao, etc. mining areas. A larger number of mines 1.1.3Water-disaster of Paleogene sandy in Shandong Province are affected by the gravel, Jurassic sandstone Shanxi Formation sandstone These aquifers can be directly water-disaster, mainly distributing in the supplied by surface water or Quaternary area which has a large thickness layer in diving water which belongs to the the roof and floor sandstone, with

297 developing tectonic fissures and rich aquifer water pressure of Ordovician is water, such as: Xinwen, Jining, Feicheng, higher, owing to water-resisting layer Tengzhou, Zhangqiu, Ningyang and broken, or the coal bed mining Taozao mines, etc. disturbance, or affected by the structure, 1.1.5 Water-disaster of Taiyuan the Ordovician karst water will Formation thin limestone breakthrough water-resisting layer, go Taiyuan Formation coal mines in all into the pit and cause water inrush under the mining areas of Shandong have the the effect of high head pressure [3]. The main coal layers, therefore the scope Ordovician karst water is usually under influenced by Taiyuan Formation thin high pressure, and often breakthroughs limestone water is large. The main the fault, the collapse column or upper developing Taiyuan Formation thin part of the tectonic fissures and makes limestone in Shandong province is mixed hydraulic contact with Taiyuan group of between several minable seam, relatively thin-layer limestone aquifer [2].Most coal close from the coal seam, and karst mines in Shandong province are in the fissure is developing, bottom Taiyuan mining process of the next group, Adding group and Benxi group limestone are the that the water-resisting layer is thinner, main aquifers which threaten the coal the coal mine is easily threatened by the mine safety production. The coal mines bottom Ordovician limestone water. The under threat of Taiyuan Formation thin influencing scope is large, with high limestone water-disaster in Shandong degree of threatening .Affected by such province are mainly distributed in west damage areas mainly include: Feicheng, areas of Shandong, with developing karst, Zhangqiu, Tengzhou, Xinwen, Zibo, such as: Feicheng mining area, Zhangqiu Yanzhou, Jining, Laiwu mining area, etc. mining area, Ningyang mining area, 1.1.7 Water-disaster of goaf and old Tengzhou mining area and Taozao gob mining area, etc. The history of many mines in 1.1.6 Water-disaster of Ordovician Shandong province of coal mining is long, limestone so many of them make a lot of different Ordovician limestone distribution degrees of mining area of goaf , old gob range is wide, with good water supplying, and the ancient mining area with water. rich water content, high water pressure. The goaf water which threatens coal Ordovician limestone water is an mining mainly displays in the threat of important water disaster of coal mine in goaf water on the level to the level, Shandong. When the confined adjacent layer goaf water shallow to deep,

298 neighboring goaf water in the mining particles [4], usually exists in loose areas. The disaster of the goaf water and sediment, the permeable performance the old gob water come suddenly and depends on the degree of pore size, shape, ferociously .What makes matters worse is sorting and arrangement, etc. when it is it can cause serious casualties and flood exposed, mining working face presents wells accident. Various types of coal water seepage, water trickling or water mines of Shandong are affected by such gushing and with more water points, less damage extensively, especially in the water yield, slow flow velocity which long mining history, the goaf area, the old leads to the water inrush threat becoming gob area. The old mining area with big smaller. Fracture channels mainly exist in and small mine doping is affected worst hard rocks, weathering zone and structure such as: Zibo, Xinwen, Tengzhou, fractured zone. Many factors decide the Taozao, Jining, Zhangqiu, Laiwu mining water permeability, such as pores, density, area, etc. filling and connectedness. Soluble rock 1.2 Gushing water channels strata suffer corrosion can become rock 1.2.1Natural channels gap, which is defined strata solution Only when a channel grows with the crack. With a low filling rate the karst is various types of detrimental water source, easy to connect, and then gushing water can water inflow or water inrush come channels come into being. Once into being. If the channel has no inrushing, the water pressure is very high connection with detrimental water source, and the velocity is very fast. That would as the fault, the water inflow or water lead to serious damages. Soluble rocks in inrush would not be appeared. The Shandong Province has a certain channels can cause coal mining water distribution, Zaozhuang, Jining, Zibo, inrush or coal mining water inflow which Feicheng, Laiwu, Weifang, there are are usually considered as gushing water other areas of Ordovician and Cambrian channels, which generally can be divided carbonate rocks. into natural gushing water channel and Pore structure is due to tectonic artificial gushing water channel. stress undermines the integrity of the Natural channel mainly refers to the rock, creating tensile, shear, pressure, rock gap and structure pore. Rock gap tensile twisting, twisting and other mainly includes pore, fracture, and fracture pressure, increasing the solution crack. Pores are made up of permeability of the rock, mainly divided accumulation from mineral or clastic into impermeable fault zone and

299 permeable fault zone. Most of inundation accident, for example, as a impermeable fault zone are attached with result ,Hutian coal mine happened 7 pressure or pressure-shear fracture, few times of water inrushing and flooded with tensile or shear fracture and high wells three times. When mining, the degree of fault cementation, good filling. overburden strata begin to move. From After coal mining, under the ground the bottom to the up, the overburden pressure and other factors, it will lead to formed caving zone, water flowing water permeable. Permeable fault zone fractured zone and bending zone. When are mostly with tensile and tensile caving fracture communicates strong twisting fracture characteristics. As for aquifers or surface water, water damage low degree of cementation on both sides is prone to taking place, such as the of the rock and limited moisture, it is Huafeng coal mine accident of easy to dewatering. However, when its conglomerate water influxing workplace side with other strong aquifer or surface repeatedly, which took place because of water hydraulic closely linked, the water small pitch between coal and aquifer irruption quantity is very high; water is when the former mining group was stable, hard to dewatering. Such faults are mined. Long-term mine drainage considered as the main channel of mine pumping makes groundwater levels water inrush. On August 17th, 2010, four decline and mine aquifer structure faults in a Shandong mine working face changed dramatically, karst channel 8602 within 100m range communication connectivity increase. So the water level Ordovician limestone water, causing the drops and a funnel comes into being and water gushing. causing collapse. Then much surface 1.2.2Artificial channels water comes into the mine, causing Artificial channels mainly refer to serious consequences. subsidence which is made by drilling 2. Two basic characteristics of coal exploration and mine subsidence, mine mine water-disaster in Shandong pump, long term drainage. province Because of the various explorations Coal mine water-disaster in drill holes are not closed or with poor Shandong province basically has the sealed quality, these holes become following characteristics: stronger water channels through aquifers 2.1Mine water source is more extensive and surface. As for low drainage capacity Considering the common roof and mines, artificial channels may cause mine floor water source, surface water, goaf

300 water, old gob water, Quaternary loose Zichuan area, six people were killed, bed water, Paleogene sandy gravel water, which is caused by illegal coal pillar Jurassic sandstone water, Shanxi mining leading to goaf water connection. Formation sandstone water, generally With the increase of mining depth, many exist in coal mine area of Shandong mining areas in Shandong province have province, but the difference in different begun to lower coal mining; coal floor degree of threat to coal mining area is confined aquifer water pressure is larger, even in the same mining area, becoming bigger, serious threat group of there exist certain differences. coal mining safety. Part of the mines, 2.2 Influence range is wide; multiple such as Suncun coal mine and mining areas at the same time are Liangzhuang coal mine, inrush areas facing the threat of a variety of water have no obvious structures, showing floor disasters threat of confined water is more Talking about the water disasters concealed and more dangerous. Therefore, influence scope, Zibo, Linyi, Xinwen, the goaf water and Ordovician water are Feicheng, Yanzhou, Tengzhou, chapter the major source of coal mine grave, Jining, Ningyang, Taozao, water-disaster in Shandong province. Longkou mining areas are affected by 2.4Water-disasters occur with close one or more of water disasters, such as links to the geological conditions and chapter grave, Tengzhou, Xinwen mining climate area, at the same time by surface water, In the plain area, with undeveloped the Quaternary loose bed, the Ordovician karst, crack, the mine is mainly affected limestone water, goaf water, Shanxi by the Quaternary loose bed water. In sandstone water. mountainous and hilly terrain, coal seam 2.3 Main damage types are outstanding outcrop exposed big, rich groundwater Goaf water and bottom Ordovician resources, receptive to recharge, limestone water are the main damage threatened by confined water surface and types of coal mine in Shandong province. Ordovician water more seriously .In the There exist abandoned old kiln and top group of coal mining, coal mine empty area in Xinwen, Zaozhuang, Zibo water-disasters are given priority to the mining. These old kilns, dotted with goaf roof and floor conglomerate, sandstone water in mining area, form a serious water. In the low group of coal mining, threat to coal mine safety in production. the mine is mainly influence by Xu For example, on June 28, 2011, in Zibo limestone and Ordovician water.

301 The rainy season of Shandong information due to a long mining history, province is mainly in July and August, leading to lots of ancient empty and old during this period, the mine accidents are kiln, and are subject to threats of flood significantly more. For example, in July season precipitation, surface water, and August, 2008, different degree of especially Mining area of Taozhuang; water inrush accident happened in Local provincial coal mines are Tianranjiao mine and Jingting mine of distributed in marginal outcrop or Zaozhuang coal, Wanglou mine of Linyi abandoned mines re-mining’s residual coal. Surface water can not only directly coal nearly, mining relationship is crush into the underground; also it can complex between mines with more offer the groundwater recharge, rainfall of recent years, the rise of ground becoming the indirect water source of water level, head water pressure’s mine flood. increase, old empty water growth, having 3 The main existing problems larger threat to safety production of coal The primary problems of flooding mines. injury prevention and cure in coal mine 3) Large trough coal and shallow of Shandong province: coal seam are facing exhaustion of part of 1）Hydrogeology information is not mining area, gradually coming into the clear. Comprehensive analysis of exploitation of the next group mine. The hydrogeology is lacking in some mines, high confined water’s threat of floor is such as empty water surveys around gob serious and water inrush risk is increasing, areas are not timely and accurate; a few both of which increase the difficulty of mines lack of geological exploration water disasters prevention. work seriously, leading to incomplete 4) The mines of Jining mining area geological data and unclear hydrological mostly distribute along rive and lake, conditions, such as Wanglou Coal Mine especially mining area affected by mining and Juncheng Coal Mine’s lake district is increasing gradually per year in recent and deep coal seam have few drillings years, such as working faces near rive and not enough hydrological and levee and lake levee grows, leading to geological information, which make it hard flood control. Although individual difficult for water prevention and control. mines have taken some measures for rive 2) Some old mines(such as Zibo, channels, flood discharge, water pits, Zaozhuang, Xinwen, etc.) still exist subsidence area, ground cracks, ancient having not enough hydrogeology kilns, etc. but governance is not complete,

302 existing a phenomenon of having hidden applicable technology. Collect and survey threats and governing every year. periodically this mine and neighboring 5) Part of old mines in order to mine abandoned old kiln situation, reduce displacement; the mining area has quickly and accurately compile the “mine been blocked. This action leads to high comprehensive hydrogeology situation” lift water problem, posing a threat to and some basic drawing and information production area. in order to realize mine water disasters 6) Attention to water prevention and potential threat situation and come up control is not enough. A few coal with relative measures which could enterprises have insufficient prevent in advance and handle water understandings of water disaster control, disasters could improve mine waterproof evading hidden perils during the damage ability. When drilling in the mine, analysis and describing dangerous explore and drain water must be in circumstances roughly and simply, and accordance with the principle of digging lack of specific targeted treatment and after exploring, and meanwhile make prevention measures. Flood prevention sure draining water effect. Jining city work mechanism is weakened in some insists to take ascertain mine mines, including unclear responsibility, hydrogeology type as important point inadequate mechanism, less professionals, whose mines have all finished wakening management work, even hydrogeology type division in order to do having no hydrological professionals in enough waterproof work. several mines 4.2 Using new technology and theory 4 Prevention and control methods of study mine water inrush mechanism water-disaster in Shandong province Water disasters mechanism and The following measures are given theory study are developed. Physics for the basic characteristic and main simulation and numerical simulation are existing questions about Shandong attached importance strengthened, and province mine water disasters. come up with new realization and 4.1Finding out mine hydrogeology understanding. It brings much convenient situation to waterproof work by utilizing computer Mine or mine area hydrogeology information to create waterproof situation was found out by combining synthesis information base and diagnose mine geophysical prospecting, drilling, system such as region and Shandong geochemical and some advanced province networking which could reach

303 contacting information and data sharing. 4.4 Increase funding Feikuang group, high college and science In order to improve mine emergence and technology enterprise cooperate to prevent drainage ability and make mine carry out mine water inrush mechanism develop safely, continually and stately, study Ordovician hydrogeology we must increase prevent govern water expedition and treatment technology equipment funding, improve mine study, and search new coal mining emergence prevent drainage ability and method so that keep mine safe. corollary equipment which could meet 4.3 Establish and complete the the need of production, and meanwhile waterproof system mend drainage equipment regularly and In order to make mine water arrange emergence drainage water disasters prevention work develop material and equipment. In addition, we successfully, we should establish and should strengthen manage funding, for complete mine water prevent example Xinkuang group spent responsibility system, precise division, 120,906,200 Yuan managing Caiwen close cooperation and order work. All river area first and second project which kinds of enterprises should strengthen remove mine surface water disaster contact with geography measure, weather, danger. waterproof and some sections, and 4.5 Improve safety train establish to prevent water disasters, Mine water disaster accidents predict handling mechanism and sharing depend on human error largely. Water mechanism. When somewhere of mine inrush accidents could be reduced by appear to dangerous situation, it must adopting a serious of measures, despite of inform quickly circumjacent all mines. complex mine condition. Zikuang mine When relative people receive dangerous group invite “mine waterproof rule” main reports or possible disasters, it firstly drafter to explain, train and combine fact disposes them before reporting. work to revise “waterproof work detailed Yankuang group explore actively to rules” in order to avoid water disaster establish long and effective mechanism accidents. waterproof safety administration and 5. Conclusions strengthen waterproof technology The geological condition of administration which realize mine area Shandong province is very complicated; waterproof safety production for 13 coal mines often face various years. water-disasters when mining. Mine

304 water-disaster management has been the [5] Jing Jidong, Shi Longqing, Li Zilin safety production problems which must etc. Research on the inrush mechanism of be solved; it needs to check out the hydro roof water in Huafeng coal mine [J]. geological conditions and summarizing Journal of China university of mining. the characteristics of water disasters. Pp642-647, 2006. Finally, targeted prevention method could be presented. When preventing water [6] State supervision and administration disasters, it also need to comply with of production safety administration, state relative rules and combine mine fact administration of coal mine safety. Coal situation to adopt positive measures in mine safety rules [M]. Beijing: coal order to reduce water disaster accidents industry press, 2011. to minimum margin. [7] State supervision and administration 6. References of production safety administration, state [1] Zhang Wenquan, Yang Chuanguo, administration of coal mine safety. Jiang Peiwang etc. Mine water-disaster Prevention and control of coal mine prevention and governance [M]. Xuzhou: water rules [M]. Beijing: coal industry China university of mining press, 2008. press, 2009. [2] Dong Shuning, Hu Weiyue. Basic characteristics of coal mine water-disaster in China and main influencing factors [J]. Journal of coal geology and exploration, Pp 34-38, 2007. [3] Wei Jiuchuan ,Li Baiying. Safety evaluation of confined water coal mining [J]. Journal of coal geology and exploration, Pp57-59, 2000. [4] Yang Rongfeng. Research on the groundwater runoff channel formation, characteristic and detection technology [D]. Changsha: Central south university, 2006.

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