Through analysing on the form of burn-change rock in Huolinhe open-cut No.1 and No.2 mining area, approach the importance of controling burn-change rock area to open-cut mining.
Temporary support of the gob side entry is of great significance to the safety mining. Taking the 1206 transportation tunnel of Shuguang Coal Mine as the engineering background, firstly, the key technical parameters of roof cutting to release pressure were given, the bolt and cable support parameters before entry retaining and the large deformation constant resistance cable reinforcement support parameters of retained entry were determined. Secondly, according to the overlying strata collapse patterns and mechanical model of gob side entry, the calculation formula of temporary support resistance in the dynamic pressure bearing area was derived. Finally, on the basis of determining the temporary support parameters, ZLQ2826/22.5/38 type of nonrepeated support and transportation equipment of alternating pressure cycles was developed, the main technical parameters and structural characteristics were analyzed, and a new type of fast and efficient non-repeated temporary support technology in the dynamic pressure bearing area was proposed. Field practice shows that the support parameters are reasonable, the support equipment and bolt support system have a good cooperative support effect, and the roof subsidence and roof separation have been effectively controlled. In the subsequent use process, the structure of support devices should be further optimized to improve the support effect.
There are a large number of welded fatigue weak points in steel deck which are prone to fatigue damage under cyclic loads.The second structural system effect has been mainly considered in domestic and international study of the mechanical properties and details fatigue of steel deck.The first structural system effect of fatigue stresses by replacing the corresponding position of fish bone beams with whole shell element through hybrid finite element method,and choosing the fatigue curve of Eurocode to calculate the cumulative damage of fatigue details.The results show that compression beam segment is no need for fatigue checking,while the effect of whole structural system can be ignored in fatigue assessment of tesion beam segment of steel deck.
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