03-大水地下矿安全开采技术、管理-EN

1、1,Water Problems, Safety Mining Technology and Solutions of UG Mine,06,Aug,2014 HBIS Mining,2,Content,一、Introduction 二、Water burst and Reasons 三、Safety Mining Technology 四、Target,3,It is always an important technology challenge of mine safety operation to avoid water risk. Water accident caused by m

2、ining will result in water burst, UG debris flow and surface collapse, which will put life and property in danger and will destroy the mine water environment. The ground water is mainly from the supply of surface water, water in the Quaternary alluvium, karst water in Ordovician and bed rock crack w

3、ater.,一、Introduction,4,（一）Sijiaying Iron Mine South 1）Sijiaying Iron Mine South（Tianxing Iron Mine）design production 20mtpa，ground cover thick with Quaternary (rich ground water)and alluvium(100200m) of ancient Luan river, near New river only 500m，many faults and fracture in Dajiazhuang ore body nor

4、th, 5 fault structures.,5,Figure 1 Bed Rock Ground Water Spatial Flow,6,2）Sijiaying South started construction in 2009. 3 shafts have already reached to bottom. One of the three auxiliary shafts reached to bottom. The other 2 auxiliary shafts is planed to get to bottom at the end of 2015. 6 ventilat

5、ion shafts reached to bottom. 5336m level ramp development, local drainage system are completed. There are some big water burst incidents which influenced the process of the contruction. While tunnelling, over 10 times severe water incidents, max. over 350m3/h，6 times water incident caused by irregu

6、lar construction, 2 times because of unknown geology condition.,7,（二）Zhongguan Iron Mine 1）Zhongguan iron mine is located in west 30km of Shahe city Hebei province. Design production 2mtpa. High grade. Ore body length 2000m, width 800m, thickness 38m. The max. thickness 193.06m, buried depth 300500m

7、. The roof of the ore body rich in fracture and watery and it is the main water bearing layer. Sha river is at the northwest of the mine, which make the surface water and ground water connected.,8,Figure 2 Zhongguan iron mine ground water field,9,2）Zhongguan iron mine is famous for water problem. Cr

8、ack karst developed and rich water area. Big water inflow 120-160k m3/d. surrounded by small coal mines, so surface industry area is confined within rock movement area. HBIS decided to use curtain grouting technology and required water plugging efficiency over 80%.,10,（一）Example： 1、 25, May,2010，whe

9、n 1# auxiliary shaft reached 115.4m, water burst happened. Water flow 400m3/h Reason: protective layer of the shaft was melting gradually, which result in connection between the fractures in protective layer and shaft. Lower fracture water broke through the protective layer through fractures and int

10、o the shaft At that time the rock are in fracture are, fracture developed.,二、Water burst and Reason,11,2、 21:00, 9, Mar. 2011，when 1# main shaft reached -279.7m，bottom 3.72m did not lining. When worker moved out the slag, big water flow happened in west of the shaft. Outlet length 3m, height 2m. Wat

11、er colour changed from black, yellow and red, finally clean. Total water flow 190m/h.,12,（二）Reasons,Many shafts, large diameter, go through Quaternary water bearing layer. Freezing method construction in Quaternary water bearing layer, mistakes in freezing technology(i.e. stop freeze in advance) Big

12、 deviation of freezing hole is the main reason of the water burst incident. After freezing, before getting the bottom, space between freezing pipe and drilling hole is the main water diversion channel, which will cause serious water burst in bed rock. Grouting using freezing holes, plug freezing hol

13、es, enhance mechanical strength of the shaft wall are the effective way of avoiding water burst and reinforce the shaft wall. Unplugged diamond holes are the safety risk during construction and mining. Large curtain engineering, design, construction and predict the curtain stability while mining. Ho

14、w to evaluate the effect of grouting. How to know the regularities of distribution of water head within curtain after dewatering. How to evaluate the effect of dewatering and curtain to ensure the mine safety.,13,三、Key Safety Mining Technology of Water Problem Mine,Plugging technology is the key in

15、HBIS mines. Now we use grouting curtain. We ensure safety by surface grouting curtain and underground grouting curtain near ore body. As for solution after water burst, we use grouting. Prevention and cure of water hazard is related to forecast technology, detection technology, far infrared, microse

16、ism, acoustic emission etc.,14,1）Extremely Thick Alluvium Water Filling Condition Study Detect deposition law, thickness, bottom boundary Test and detect watery and water level dynamic regulation Detect and study weathering thickness, element, water permeability Numerical simulation of dynamic water

17、 bearing effect in weathering area under condition of water dynamic. Numerical simulation of weathering zone water proof effect under mining dynamic,15,2）Geological tectonodynamics analysis and water burst regulation study Covered by thick alluvium and magnetic field interference, fault structure de

18、tective technology Fault structure geometry, combination law and dynamics analysis New tectonic stress field effect. Iron mine fault structure watery detect and structure water control regulation analysis Bed rock crack water enrichment, migration,16,3）Grouting curtain, water proof hull rebuild tech

19、nology near ore body Skylight detect of weathering zone and grouting Water proof pillar in water-rich faults zone Grouting reinforcement technology in water burst structure while mining Predict small structure, water burst omen monitor and ground water isolation Separate water and ore in working fac

20、e and strong drainage technology,17,4）Water burst accident pre-warning and emergency control study Monitoring technology in drifts and mining area Fast identify water burst resource Grouting technology of UG water burst Drainage of UG emergency,18,5）Surface water and ground water protection Dynamic m