Papers by Keyword: Mining Subsidence Area

Abstract: Multilayer fuzzy synthetic evaluation is an effective method of the qualitative analysis into the quantitative analysis, and can reflect the different levels of objective things factors, avoiding the difficult to assign weights due to excessive factors. Geological environment of Jiawang coal mining subsidence area in Xuzhou was evaluated with an indices system based on multilayer fuzzy synthetic evaluation. Through evaluation, the serious damage region of geological mining of Jiawang mining subsidence area is 1918.966 hm², and the more serious damage region is 2524.088 hm², and the less affected area is 1366.971 hm². The results showed that the geological environment of Jiawang mining subsidence damage is more serious. The farmland was destroyed seriously, and water due to land collapse was quite serious, which was difficult to land reclamation. It is believed that this work may provide scientific reference for land reclamation and landscape ecological restoration of coal mining subsidence area.

Abstract: The evaluation of engineering-construction suitability in mining subsidence area is a comprehensively decisive issue which is multi-factor and multi-level. Based on the analysis of basic influential factors of the engineering-construction suitability and the special influential factors of mining subsidence-area, uses the model and the technical route of Analytic Hierarchy Process (AHP), a hierarchical comprehensive evaluation index system is constructed. After making the qualitative and quantitative analysis, every index is assigned a value in different levels and the calculation model for evaluation on the suitability of land used for engineering construction in the mining subsidence area is built with the method of multi-factor weighted composite index. At last, the classification standard of suitability is offered On the basis of above-mentioned analysis.

Abstract: To enhance the effective of the land in mining subsidence areas, realize the development of new rural construction and urbanization. According to the geological and mining conditions, the scale, shape and regularity of the potential crack areas in the coal goafs, separated overburden strata, and the influencing factors which affect the deformation foundation of architecture and stability are studied. Probability integral method is used to establish the further deformations formula of the building foundations in mining subsidence areas. The monitoring data from the ground observation stations are used to invert the further deformation predicting parameters, the surface further deformations of each coal goafs, and the whole surface’s further deformations are calculated by the superposition method. The foundation further deformations, geological structures, etc, are comprehensively taken into consideration. The stability of the building foundations in mining subsidence area are analyzed and evaluated. Research results are very valuable to process, design, and plan the foundations of the buildings in coal mining subsidence areas.

Abstract: An experiment extracting CBM with surface borehole from mining subsidence area of a 6.25 meters thick coal-bed workface was done in Jincheng city. The test borehole was designed three stages based on the geologic structure of test field. During underground workface passed through borehole, the operational status of well was recorded and the deformation of casing was detected four times. Test has shown that the highest pure flow of surface borehole can reach 8m3/min which proves that the methane extraction technology with surface borehole from mining infection zone has a bright future for application in Jincheng city. But, how to maintain the stability of casing avoiding damage is still a problem, which should be resolved before the drawing technology is used in Jincheng extensively. Besides, the ordinary protecting skills for borehole used in oil exploitation cannot take a satisfactory effect to protect tube against damaging due to overburden rock movement during mining. The casing will be damaged at several positions, especially near the junction of soft and hard strata. It may be right measure to expend the diameter of tube or install special defensive joints at the places where will deform badly under the mining influence.

Abstract: Abstract. This paper, taking Tangshan City as an example, through analysis of the ecosystem’s carrying capacity before governance, elaborates the necessity of mining subsidence control, studies three different management modes, analyses the feasibility of global ecological management mode, and, from different views, evaluates their treatment effects.

Abstract: The performance of resisting foundation displacement of a typical single return circuit transmission tower under all kinds of load conditions including foundation horizontal displacement, foundation vertical uneven downward displacement was analyzed by finite element modeling. Results showed that stability failure of single steel angle represents tower’s limit state under foundation displacement. And the corresponding foundation displacement limits were calculated. Results indicate that foundation pull condition is more dangerous than press condition. Under complex foundation displacement conditions, foundation horizontal displacement is primary factor leading to stability failure of towers. Under foundation press condition and pull condition, wind load is primary factor. Result also indicates that, tower does not fail when foundation displacements are smaller than 1.25% (under foundation press condition and pull condition) or 0.5% (under single foundation sink condition) of tower root distance.

Abstract: Finite element models, established using ANSYS, given the soil - structure interaction phenomena produced at the interface between the reinforced concrete structure and the soil, have been used to perform a parametric study of the strengthening design of the foundation and the sluice chamber within mining subsidence area. High pressure jet grouting pile is adopted to reinforce the foundation, this analysis model is simplified by the transformation from the pile foundation to the solid foundation, which reflects the characteristic of pile foundation. The strengthening design of the sluice chamber is a renovation from open style to frame, to increase the integral property. It is indicated that, using high pressure jet grouting pile to reinforce the foundation can apparently improve the stability of sluice in mining area. Nevertheless, it can't improve the stability of sluice through reinforcing the sluice chamber.