Surface collapse caused by mining

1. Subsidence is a geological phenomenon that we often hear about recently. There are many reasons for this, not all of which are caused by over mining. There are three reasons for the occurrence:
(1) karst landform. The limestone deposits in South China are generally thick and easy to form karst landforms. There are cavities proced by water flow in the deep underground, and ground subsidence will occur under stress or vibration. This is the reason why the south is prone to subsidence
(2) over mining. The excavation of underground mine is often completed by shaft, inclined shaft and underground roadway, so the underground cavity is proced. If it is not filled, it is easy to change the surrounding rock stress, become unstable and cause ground subsidence
(3) inferior construction. Many of the ground subsidence phenomena in many cities are e to the lack of technology and quality control ring the construction, and the use of low-grade cement and steel bars, which leads to the low level of concrete. Under the pressure of buildings and traffic, ground subsidence may occur
among them, there are many requirements for ground pressure management in mining science. At the same time, filling method will be adopted to prevent the occurrence of ground subsidence. In engineering, ground subsidence can be eliminated. But whether it can be done depends on the specific situation. The first is natural conditions, which can only be achieved through monitoring
the rapid use of groundwater in cities will lead to the decrease of surface water level, which will lead to the decrease of pore water pressure in sandy soil, break the original stress balance and lead to land subsidence. But this settlement is often the whole settlement, which is different from the small-scale subsidence.

2. Mining land refers to mining, quarrying, sand (sand) field, salt field, brick kiln and other ground proction land and tailings stacking land.

3. This is really true. It was proced by Japan's Kobe Steel. I am a member of the company.

in 1905, Kobe Steel Co., Ltd. was founded
in 1930, the first construction machinery in Japan was proced: 50K electric mining single bucket excavator< In 1936, we began to proce 30K electric dragline excavators< In 1946, the steam type single bucket excavator was proced
mechanical excavators (northwest type) were proced in 1947< In 1949, we began to proce 15K diesel engine driven dragline excavators< In 1952, we began to proce single bucket excavator driven by 22K diesel engine
the proction of 10kt and 20kt tyred cranes started in 1953< In 1954, the 220a diesel driven pile driver was proced
in 1955, through an agreement with harnischfeger, the crane proction technology was obtained< In 1956, we began to proce 255a diesel engine driven single bucket excavator and 355kd bucket dredger< In 1957, 255tc tyre crane and 255a-cl crawler crane were proced
in 1960, the 2000th single bucket excavator came off the proction line
proction of 335g, 655g and 955g grab mining dredgers and LA22 pile drivers started< In 1962, we signed a technical agreement with POCLAIN, a French manufacturer
set up the Construction Machinery Research Institute of Shengang in Dawa plant< The first hydraulic wheel excavator ty45 was proced in 1963
start proction of 155b-tc tire crane
in 1964, we began to proce 300 series tire cranes< In 1966, 325 crawler cranes were proced< In 1967, h208 hydraulic excavator was proced
start proction of kg60b, kg80b and kg75b floating crane barges
proction of H212 hydraulic tire crane started< In 1968, the first 10A small hydraulic excavator was proced in Japan
start to proce ys1000 hydraulic excavator with large volume
proction of R series hydraulic excavators started
in 1969, we began to proce T series hydraulic tyred cranes
start proction of R150 cranes adapted to rough terrain
in 1970, he invested in harnischfeger company in Australia
start proction of 670f and 9125f floating crane barges< In 1971, we began to proce K series pile drivers driven by diesel engines< In 1972, ge1500 grab mining barge was proced
LK series tire loaders were proced in 1973
start proction of FD series floating crane barge< In 1977, Mk7 grab dredger was proced
start proction of F & G1000 floating crane barge and grab dredger
start to proce 5000 Series crawler cranes< In 1978, KISCO, a sales subsidiary, was established in Singapore
K series hydraulic excavators were proced in 1979
the last major part of Dawa factory was completed in 1980
established sales subsidiaries in Houston and Texas in 1982
in 1983, we began to manufacture and supply cranes to P & H by OEM
start to proce C series hydraulic excavators
start to proce pk160 and RK200 cranes suitable for rough terrain
start proction of 7450 hydraulic crawler crane
start proction of 5650 crawler crane: lifting capacity 650 tons
in 1985, we began to proce D series hydraulic excavators equipped with kpss 7000 series hydraulic crawler lifting devices< In 1986, Shengang Construction Machinery Co., Ltd. was established
in 1987, Mark II series hydraulic excavators equipped with rotating signal flashlights were proced< In 1988, KCM was established in Calhoun, Georgia, USA
start to proce SK series small excavators (super small)< In 1989, SS1 ultra small excavator was proced
proction of sk100w wheel excavators started
start to proce Mark III series hydraulic excavators equipped with computer-controlled ITCs device
start proction of RK 70m small crane suitable for rough terrain
kcme was established in the Netherlands in 1990
we started to proce ur series hydraulic excavators
start proction of F & g2345 floating crane and grab dredger
in 1991, BM 1200 crawler crane for infrastructure construction was proced
start to proce rk series cranes suitable for rough terrain< In 1992, SK series small excavators were proced< In 1993, Mark IV and Mark V series hydraulic excavators were proced
SL3000 crawler crane proction started: lifting capacity 800 tons< In 1994, ckcm was established in China
the cumulative output of hydraulic excavators reaches 100000 units
proction of 7000 series hydraulic crawler cranes started< In 1995, PK series cranes adapted to rough terrain were proced
two US branches, Kai and KCM, merged to form a new Kai (now kcma)< In 1996, TKCM was established in Thailand to manufacture hydraulic excavators
start proction of SR series small excavators
kcmf was established in 1997< In 1998, SR series hydraulic excavators were proced
start proction of bm700hd crawler crane for infrastructure construction
Yougu heavy instry (Hiroshima factory) and Dawa factory have passed ISO9001 certification< In 1999, the Construction Machinery Department of SG was reorganized into an independent company named as SG Construction Machinery Co., Ltd
start to proce dynamic acera series hydraulic excavators
proction of 7200 crawler cranes started
proction of SR series small excavators started in 2000
start proction of sk80msr hydraulic excavator
signed a global cooperation agreement with CNH global (Netherlands) of Fiat Group in 2001< In 2002, Yougu heavy instry (Hiroshima factory) and Dawa factory passed ISO9001 certification
KCa (Australia) and KCMS (Shanghai) were established to sell construction machinery, and fkcm (Italy) was established to proce and sell hydraulic excavators at the same time
KSCM service center was established in Shanghai in 2003
set up ckcmg holding and sales company in China
http://www.kobelco-jianji.com/aboutus/kcm/history.asp

4.

1 Determination of the classification system of mining subsidence land

the land resources and coal resources in the subsidence area of Quantai coal mine in Jiawang District are developed and utilized at the same time, forming a compound ecosystem of instry and agriculture, so it belongs to a fragile ecosystem of destruction more than construction and development more than renovation. Due to the different mining methods, coal seam thickness, burial depth, roof conditions, management and technical level of the mining area in the study area, the ground collapse, water accumulation and their harm degree are also different. In order to facilitate the research and comprehensive development and utilization, the collapse land should be reasonably classified before the information investigation and evaluation. According to the characteristics of the study area, the classification system of mining subsidence land in Quantai District of Jiawang District is established by using the classification method of subsidence land nature (table 6-1), which is mainly divided into non waterlogged subsidence dry land, subsidence swamp land, seasonal waterlogged subsidence land, perennial waterlogged subsidence land and non subsidence land (Mao Hanying et al., 1998; Wang Xingfeng et al., 2007)

Table 6-1 classification system of mining subsidence land in Quantai, Jiawang District; ② From the point of view of the whole subsidence pit or mobile basin, the surface subsidence is continuous, and from the point of view of the internal specific form, it is also shown as uneven unlating state, that is, the micro discrete form; ③ Because of the high groundwater level, when the ground collapses to a certain depth, it will lead to water accumulation in the collapse area; In addition, the rainy season also makes the subsidence area accumulate water; ④ The surface cover is heterogeneous. There are not only ponding area, but also green space with no ponding in the subsidence area, and bare land with salinization caused by ponding. The different land cover patches are heterogeneous and irregular

According to the remote sensing image, the location of the mine and the geological structure characteristics of the mining area are firstly understood, and then the mining subsidence area is interpreted according to the color, vegetation, micro landform and water body on the image. The main interpretation marks are as follows: ① tensile cracks often appear at the edge of the mining subsidence area, These tensile cracks often form curved stripes and textures on aerial photographs. The water is rich in the tensile fracture and the vegetation is often well developed. ② The man-made buildings in the subsidence area have been damaged, such as the collapse of riverbanks and roads, and the forced relocation of residential areas. These images are indirect interpretation signs of mining subsidence areas. ③ The land use efficiency of collapse area is significantly lower than that of non collapse area, and there are more abandoned land, which is easy to be distinguished from non collapse area. ④ The shape of surface water in the subsidence area is irregular, while the shape of artificially excavated ponds is regular. ⑤ In the reclamation area of the subsidence area, the plants in the reclamation area are rare, and the color is gray to grayish white, which is also an important sign to judge the mining subsidence area (Lu Xianzhang, 1997; Zhang Quanjing, 2000)

according to the characteristics of different types of mining subsidence land, the spectral characteristic spots of mining subsidence land were selected (table 6-2)

Table 6-2 spectral characteristics of mining subsidence area

continuation table

(IV) mining subsidence area information extraction

the technical process of mining subsidence area information extraction in Quantai coal mine of Jiawang District is shown in Figure 6-2

Fig. 6-2 flow chart of Mining Subsidence Information Extraction Technology

5. Over the past 30 years, China's groundwater exploitation has increased by 2.5 billion cubic meters per year, effectively ensuring the needs of economic and social development. However, groundwater overdraft in the northern and eastern coastal areas is becoming more and more serious. According to preliminary statistics, more than 100 large-scale groundwater drawdown funnels have been formed in China, covering an area of 150000 square kilometers, 620000 square kilometers of over exploited areas, and nearly 60 cities have been seriously over exploited, resulting in the disconnection of many springs and the depletion of some water sources. Groundwater overdraft areas are mainly distributed in North China Plain (Huang Huai Hai Plain), six major basins in Shanxi, Guanzhong Plain, Songnen Plain, lower Liaohe plain, some basins in northwest inland basin (Shiyang River, Turpan Basin, etc.), Yangtze River Delta, southeast coastal plain, etc. The groundwater overdraft in Hebei plain and Beijing plain reached 50 billion cubic meters and 6 billion cubic meters respectively; Due to the serious land subsidence, Tianjin can not continue to overdraft groundwater. The long-term continuous over exploitation has resulted in the continuous decline of deep groundwater level and the continuous rection of storage resources in North China Plain. At present, the groundwater level of nearly 70000 square kilometers is below sea level; The maximum drop of water level in the central area of deep groundwater funnel in Cangzhou city is nearly 100 meters, which is more than 80 meters lower than sea level. 2. Land subsidence nearly 70 cities in China have caused land subsidence e to unreasonable exploitation of groundwater. The subsidence area is 64000 square kilometers. The largest settlement of more than 2m is in Shanghai, Tianjin, Taiyuan, Xi'an, Suzhou, Wuxi, Changzhou and other cities. The settlement of Tianjin Tanggu reaches 3.1m. The land subsidence in Xi'an, Datong, Suzhou, Wuxi and Changzhou is accompanied by ground fissures, which poses a serious threat to urban infrastructure. In addition, Hebei, Shandong, Yunnan, Guangdong and Hainan are the places where ground fissures occur. 3. The large-scale concentrated exploitation of groundwater and mine drainage in karst collapse causes frequent ground collapse, which tends to be concentrated in towns and mines. The scale is becoming larger and larger, and the loss is increasing. According to incomplete statistics, more than 1400 karst collapses have occurred in 23 provinces (autonomous regions and municipalities directly under the central government) in China, with a total number of more than 40000 collapse pits, posing a serious threat to national economic construction and people's lives and property. For example, on August 4, 2003, the karst collapse in Yangchun City, Guangdong Province, resulted in the collapse of six houses, two casualties and more than 400 people in more than 80 households; On April 6, 2000, the karst collapse in Hongshan District of Wuhan caused the collapse of four houses, which affected more than 150 households and 900 people; In the 1980s, the karst collapse in Tai'an, Shandong Province caused the Beijing Shanghai railway to be interrupted for a long time and slow down; A train overturning event occurred on Guikun railway e to karst collapse. The ground collapses. Over exploitation of karst groundwater causes ground collapse, which is mainly distributed in Guangxi, Guangdong, Guizhou, Hunan, Hubei, Jiangxi and other provinces (regions), and also in Fujian, Hebei, Shandong, Jiangsu, Zhejiang, Anhui, Yunnan and other provinces (regions). Kunming, Guiyang, Liupanshui, Guilin, Tai'an, Qinhuang and other cities have the most typical karst collapses, and some mining areas in Hunan and Guangdong have the largest number of collapses caused by mine drainage. There are more than 3000 karst collapses in China, with an area of more than 300 square kilometers. 4. Seawater intrusion occurs in the Bohai rim, some coastal cities in the Yangtze River Delta and the southern coastal areas. Due to excessive exploitation of groundwater, seawater intrusion occurs in varying degrees, showing a trend from point intrusion to area intrusion. Seawater intrusion makes groundwater salty to varying degrees, which makes it difficult for local people to drink water. Land salinization occurs. Most farmland proction is reced by 20% - 40%, serious by 50% - 60%, very serious by 80%, and even no proction in some places. The South Bank of Laizhou Bay in Shandong Province is one of the areas with the most serious seawater intrusion in China, resulting in the scrapping of more than 8000 agricultural wells, the difficulty of drinking water for 400000 people, the loss of proction capacity for 600000 mu of cultivated land, the cumulative rection of grain proction by 3-4.5 billion kg, and the direct economic loss of 4 billion yuan. 5. The results of a new round of groundwater resources assessment show that the groundwater quality in China is generally good. According to the distribution area statistics, 63% of the groundwater can be used for direct drinking, 17% can be used for drinking after proper treatment, 12% can not be used for direct drinking but can be used for agriculture and some instrial sectors, and less than 8% of the groundwater is salt water with salinity greater than 5 g / L and a small amount of seriously polluted groundwater, which is not suitable for direct use or can be used only after deep treatment. However, with the rapid increase of unreasonable or substandard discharge of urban and instrial "three wastes" and the extensive use of pesticides and chemical fertilizers in agricultural and pastoral areas, the groundwater pollution in China has become increasingly serious, showing an expanding trend from point to surface, from shallow to deep, from urban to rural. The monitoring results of 195 cities in China show that 97% of the urban groundwater is polluted to different degrees, and 40% of the urban groundwater pollution tends to increase; Among the 17 provincial capital cities in the north, 16 pollution trends increased, while among the 14 provincial capital cities in the south, 3 pollution trends increased. 6. Soil salinization the problem of native soil salinization is mainly distributed in Songnen Plain and Northwest China, and also in Huang Huai Hai area. The main provinces are Heilongjiang, Jilin, Inner Mongolia, Ningxia, Gansu, Xinjiang, Hebei, Henan and Shandong. The long-term climate drought, the continuous increase of agricultural irrigation and instrial water consumption, resulting in the decline of groundwater level, the enrichment of salt in the surface soil is leached to the ground, the degree of soil salinization is reced, and the salinization area is reced. The salinization area in China is only 31.4% of the distribution area in the early 1980s. The problem of secondary soil salinization caused by human activities is mainly distributed in the middle reaches of the Yellow River and the agricultural areas in the northwest inland basin where a large amount of surface water is used for irrigation. In addition, high arsenic water, high fluorine water and low iodine water are distributed in some areas of China. More than 100 million people in China are drinking substandard groundwater, which makes the people in these areas suffer from endemic diseases such as arsenic poisoning (skin cancer), endemic goiter, endemic fluorosis and Keshan disease.

6. Full moon sweating is a good choice, generally can go to a better environment bath, conditional also can own at home, with wormwood plus some health care materials, sweating.

8. There are many kinds of agents. One of them doesn't need capital, just send pictures and text with him. The price he gives you is relatively low, and then you sell it to others at your own price

9. Mining causes geological subsidence and small earthquakes
people may be injured and houses may collapse
it will cause the geological decline and the village will become a lake
we need to report to the government in time to protect our own interests.

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1. Also known as e-money or digital cash, it is a very important electronic payment system, which can be regarded as the electronic or digital simulation of real money. E-cash exists in the form of digital information and circulates through the Internet. But it is more convenient and economical than real money. Its simplest form includes three main bodies: business, user and bank; And four security protocol processes: initialization protocol, withdrawal protocol, payment protocol, deposit protocol. The first e-cash scheme was proposed by Chaum [2] in 1982. It uses blind signature technology to realize it, which can completely protect the privacy of users. But this kind of completely anonymous e-cash also provides convenience for many criminals. They use the complete anonymity of e-cash to carry out some illegal and criminal activities, such as corruption, illegal purchase (such as buying drugs, arms, etc.), extortion, etc. Even if the police get the stolen money, they can't catch the criminals. For this reason, a reasonable e-cash system should be incomplete or conditional anonymous. In 1995, Stadler et al. [3] proposed the concept of fair blind signature, which can be used in conditional anonymous payment system. In 1996, Camenisch et al. [4] and Frankel et al. [5] independently proposed the concept of fair off-line electronic cash for the first time, and gave two schemes. The anonymity of users in fair e-cash is incomplete. It can be revoked by a trusted third party (TTP), so as to prevent criminal activities by using the complete anonymity of e-cash
2. E-cash is a relatively mature means of electronic payment, which is suitable for small transactions through the network.