Advanced Materials Research Vol. 511

Abstract: In order to study the environmental impact of coal mining, took Expanding and Improving Project on Xihe Coal Mine (EIPXCM) as an example to investigate and study. Firstly, investigated its coal bed structure and coal quality and summed up its features and scale. The results show that the located stratum is mantle fold with intensive cracking activities. The coal bed is thin and uniclinal with a dip angle of 35°. So long wall retreating mining method along the strike will be adopted. Sulfur and phosphorous in the coal are low as 0.25～0.35% and 0.001～0.007% respectively. A key winding inclined shaft and another inclined shaft for workers and air return will be built. Production capability of the mine is 60 000 t/a with 1.9 years of workable period. Secondly, water cycling, equilibrium, treatment, flying ash pollution, coal mine safety and entironmental influence are analyzed. The results are that the relative gushing amounts of CH4 and CO are 2.5 m3/t and 0.34 m3/t respectively. Coal-dust explosion index is more than 40%. It indicates a low explosion possibility. The project will inevitably lead to surface subsidence and collapse resulting in further soil erosion to some extent. Finally, some precaution measures are also proponed. This will lay a sound foundation for later entironmental influence assessment.

Abstract: To assess entironmental feasibility of Expanding and Improving Project on Xihe Coal Mine (EIPXCM), according to related regulations and influence scope of the project, regional ecosystem was investigated firstly. The results indicate that the located city has better natural environment. The city locates mid-temperate zone and has hilly geomorphology. The soil area accounts for 95.0% and is fertile. Dark brown soil has biggest distribution and accounts for 70%. Morever, it has good hydrology conditions such as rivers and ground water. Rate of forest coverage is 38% in which are mostly secondary and planted forests. Furthermore, it has plenty of wildlifes and plants. It also has abundant mineral resources in which coal, graphite and sillimanite are richest. Secondly, current situations of smaller regional ecosystem were evaluated. Evaluation of cropland ecosystem shows agricultural acreage accounts for 62%. The biomass amounts of crop land vegetation are very low. Soil evaluation shows that there are high organic and N contents, but low P content. Land utilizing evaluation shows that the land are suitable for plowland, forest land and grass land. Paddy field should be more developed. Gradual decreasing of grass land area should be noticed and prevented. All this work laid a sound foundation for next entironmental influence prediction and appraisal.

Abstract: The paper describes the research on deformation mechanism method of channel steel cold roll forming by finite element software ABAQUS, and typically analyzes stress and strain change rule of the fifth pass cold-formed process. Simulation results show that: on the whole, the equivalent strain and stress value of three typical parts tend to increasing with time increases

Abstract: Pit excavation and precipitation are bound to cause the changes of groundwater level and stress field in the soil body around the pit, which lead to the deformation of soil body and building around pit and produce varying degrees of influence on the surrounding environment. Based on variable and invariant total stress, this paper calculates the increment of effective stress in the influence range of precipitation, drawing a conclusion that decrement of pore-water stress and increment of effective stress are not simply equal. The methods of calculating surface subsidence caused by the foundation precipitation are summarized in this paper.