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Xue D.-C.,China University of Mining and Technology | Xue D.-C.,Xishan Coal and Electricity Group Co | Wu Y.,China University of Mining and Technology | Zhang K.,China University of Mining and Technology
Caikuang yu Anquan Gongcheng Xuebao/Journal of Mining and Safety Engineering | Year: 2013

Bolt axial force is an important indicator of its working state in coal mine tunnel. The current detection means can not able to carry out random, rapid, non-destructive testing technology. In this paper, the relationship between horizontal natural frequency of anchoring system and bolt axial force has been established based on the principles of structural dynamics. By means of the dedicated electro-hydraulic servo system of bolt tensile testing, the influence of bolt diameter, anchoring state and surrounding rock conditions on the lateral vibration frequency of anchoring system and bolt axial force has been measured. The results show that the lateral vibration frequency of bolt anchoring system and bolt axial force have a good correlation, and the surrounding rock condition is one of the main factors affecting the lateral vibration frequency. The relationship between lateral vibration frequency and bolt axial force can be described by logarithmic function. Base on research founds, the nondestructive testing technology of bolt axial force has been developed. The field application shows that the technology can randomly, non-destructively detect the axial force of bolt in the tunnel. Source


Meng J.,China University of Mining and Technology | Meng J.,Xishan Coal and Electricity Group Co
Advanced Materials Research | Year: 2013

The fuzzy Fault Tree Analysis (FTA) of mine ventilation system is set up based on thorough composition of the system, with triangular fuzzy number being used as probability of elementary event and "mine ventilation system fault" being deemed as top event. In this paper, the reliability of FTA has been analyzed and applied to a mine in Gansu Province. The result shows that the minimum cut set of fault tree is 549 and the main reason why it has a huge number of minimum cut set is Level 1,Event 7,"Monitoring feedback system failure". The reliability of top event and Level 1 event is low, and fuzzy failure probability of top event is (0.009, 0.014, 0.009), the maximum of which is 2.3% of it. The degree of fuzzy importance of elementary event is the highest in Level 1,Event 7. The maximum of fuzzy importance is 0.0843 by the normalization and the rest vary from 0.0050 to 0.0100 mostly. © (2013) Trans Tech Publications, Switzerland. Source


Yu L.,Xishan Coal and Electricity Group Co
Meitan Xuebao/Journal of the China Coal Society | Year: 2011

To the detection of chain-broken in armoured face conveyor, a scraper detecting sensor was proposed in which special magnetic field is constructed in side section of conveyor chute and hall element is used as sensitive element to the magnetic field. The fault of single chain-broken can be detected based on the sensor. It is presented that the magnetic intensity difference between scraper going through the sensor and no scraper going through it (MID) is one of the most important performance parameter. After modeling magnetic field, the relationships between MID and length of permanent magnet, location of permanent magnet and location of hall element were researched based on ANSYS. The results indicate that MID reaches peak 308 Gs when the length of permanent magnet is 100 mm and the permanent magnet is at such a position where the distance from the edge of side section of conveyor chute is 30 mm and the hall element from the edge of pan of chute is 80 mm. Measurement on the prototype designed on the rule is carried out. MID of the prototype is 265 Gs. It is enough to scraper detection. Source


Wang Y.-B.,China University of Mining and Technology | Wang Y.-B.,Xishan Coal and Electricity Group Co | Shan R.-L.,China University of Mining and Technology | Cai W.-L.,China University of Mining and Technology | And 4 more authors.
Meitan Xuebao/Journal of the China Coal Society | Year: 2011

The factor questionnaire influencing coal roadway driving in Xishan mining area was designed on the basis of site investigation and Delphi method. There are 6 first grade indexes and 28 secondary indexes which include each factors influencing driving speed of coal mine. By analysis of reliability, lanckerbaha figure is between 0.8 and 0.9, therefore the inside reliability of the list is acceptable. By the test of KMO and Barlett, it is suitable for factor analysis. Based on these investigation results, questionnaire outcome was carried out with SPSS 17.0 by analyzing factor, and 7 common influencing factors were abstracted about driving speed of coal area from the questionnaire. Factors include crew management, prediction skill of engineering geological conditions, equipment management, optimization of supporting parameter, staff quality, conditions of project rock, performance management. Aiming at the seven common factors, 7 specific suggestions for driving speed of coal mine were put forward. Source

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