TD325 S20030033 2006 02 18

2006 02 18

Study on the Mechanism of Ground Subsidence and Evaluation of Ecological Safety in Beiminghe Iron Mine 100083 Candidate Zheng xinhua Supervisor Cai meifeng School of Civil and Environment Engineering University of Science and Technology Beijing 30 Xueyuan Road Haidian District Beijing 100083 P.R.CHINA

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Study on the Mechanism of Ground Subsidence and Evaluation of Ecological Safety in Beiminghe Iron Mine Abstract Ground subsidence is one of the most important engineering geological disasters in mine district, which seriously endangers the production safety and destroys ground environment. In this paper, mechanism of ground subsidence in Beiminghe iron mine was studied, and ecological safety evaluation of the mine area was analyzed. In the paper, firstly, the damage of ground subsidence and the significance of research were analyzed. Secondly, the mechanism and development process of ground subsidence which aroused by underground mining were studied. Water penetrating back of Beiminghe iron mine come into being underground moving water. Based on this, models of collapse mechanism aroused by water level descending and rising and surface water penetrating in were put forward. Based on the prediction of ground subsidence caused by mining in probability integral method, developing uniform coordinate system, these two forms of subsidence due to different causes were superimposed roughly on conditions as optimal as possible. In this way, ground subsidence problems from dual effect of mining and groundwater drawing will be solved consequently. Finally, evaluation of ecological safety in the mine area was analyzed. Appropriate ecological safety target system was established. Ecological safety evaluation of ground subsidence was analyzed. Key Words ground subsidence, mechanism, prediction, evaluation of ecological safety - 3 -

... 2 Abstract... 3... 1 1... 2 1.1... 2 1.2... 4 1.2.1... 4 1.2.2... 6 1.3... 10 2... 12 2.1... 12 2.2... 14 2.2.1... 14 2.2.2... 15 2.3... 16 2.4... 17 3... 18 3.1... 18 3.1.1... 18 3.1.2... 18 3.1.3... 18 3.2... 22 3.2.1... 23 3.2.2... 23 3.3... 24-1 -

3.3.1... 25 3.3.2... 26 3.4... 27 3.4.1... 27 3.4.2... 28 3.4.3... 29 3.4.4... 30 3.5... 32 4... 33 4.1... 33 4.2... 34 4.3... 36 4.4... 37 4.5... 37 4.5.1... 38 4.5.2... 38 4.5.3... 39 4.5.4... 39 4.5.5... 39 4.6... 40 5... 41 5.1... 41 5.1.1... 41 5.1.2... 42 5.1.3... 44 5.2... 45 5.2.1... 45 5.2.2... 45-2 -

5.2.3... 47 5.2.4... 50 5.3... 51 5.4... 52 5.4.1... 52 5.4.2... 52 5.4.3... 53 5.4.4... 55 5.5... 58 6... 60... 61... 65...66-3 -

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1 1.1 [1] [2] [3] 500km 2 30 2.5-6.5m 1945 5.5 63.73km 2 30m 6m 130cm 80 114km 2 193km 2 [4] 1-1 2-2 -

1 [5] [6,7] - 3 -

2004BA615A-18 1.2 1.2.1-4 -

60 (Berry) [8,9] Sales 1979 1983 Conroy Gyarmaty full profile borehole extensor-meter full profile borehole inclinometer [10] 1965 [11] 1979 [12] 1981 [13] Weber 1983 [14] [15] 1993-5 -

1985 1992 [16] [17] [18] [19] Knothe 1.2.2 [20] Hooke [21] - 6 -

1 1898 1933 [22] I p = ( γ 3 1)(1 n) 1-1 I p γ 3 n 1 I p 1-1 2 2 1 1 KJ MK J = ( ) 1-2 2 2 2 n 2n 2 2 E d Mu = M = Ed ( ) kgm 2 /d 2 M kg u m/d K m/d J n 1-2 K n E J J E d d - 7 -