Fushun West open-pit Mine has been mined for 100 years. Under the influence of multi-chain disasters such as landslide, ground fissure and debris flow, buildings have produced irreversible damage. Although the slope treatment project has been basically completed, there is still a risk of further damage to the building. Therefore, the damage characteristics of the surrounding buildings were sorted out and the damage grade area is divided into four levels. A reinforcement system combining rigid anti-deformation reinforcement and flexible absorption deformation of buildings was proposed. According to the simulation results of the whole building model and the key bearing component model, it can be seen that the damage volume of the building structure can be reduced by about 6.05 percentage points by using the underground continuous wall reinforcement, and the damage volume of the building foundation can be reduced by about 3.67 percentage points by using the foundation bolt reinforcement. The flexible absorption deformation method filled with ductile mortar can reduce the damage volume of components by about 11.15 percentage points. Therefore, the reinforcement system can provide technical support and reference for the reinforcement project of urban buildings around open-pit mines.
In order to study the influence of the number of cracks(0, 1,2 and 3) on the mechanical properties and failure mode of sandstone under the condition of acid dry wet cycle, the specimens were immersed in solutions with pH of 2.0, 4.5 and 7.0 for 0, 1, 3 and 5 times and then subjected to uniaxial compression tests. The results show that the peak strength and elastic modulus of the specimens immersed in different pH solutions gradually decrease with the increase of the number of dry wet cycles and the number of cracks, and the deterioration of the damage caused by it aggravates the corrosion damage of the specimens immersed in chemical solutions. When the pH is 7.0, macro cracks induce the development of cracks in sandstone failure, and with the increase of the number of cracks, the failure mode of sandstone changes from shear failure to tension-shear failure.
优化喷雾雾化特性是提高矿井喷雾降尘效率的有效方法.为研究矿井水Na+、K+离子浓度对其雾化特性的影响,提高矿井粉尘治理效果,采用表面张力测量仪和激光粒度测试系统表征不同矿井水的表面张力和雾化特性,分析矿井水中Na+、K+离子浓度引起的表面张力差异及其对雾化特性的影响.结果表明:低离子浓度条件下,矿井水表面张力与其Na+、K+离子浓度呈正相关.在相同喷雾压力下,雾滴粒径与表面张力成正相关,降低矿井水表面张力可提高降尘效率;表面张力减小可延长雾化区分布范围,延长粉尘捕集范围,增加粉尘沉降数量;雾场中各雾滴粒径随表面张力减小而逐渐呈现均一性分布,这有利于提升雾滴对粉尘的润湿能力.研究结果对优化喷雾雾化特性,提高喷雾降尘效率,促进矿井水资源治理具有重要意义.
The study on the competitive adsorption characteristics in carbon dioxide displacement of coalbed methane is of great significance for improving coalbed methane recovery by carbon dioxide injection（CO 2 -ECBM）. Based on Darcy seepage, Fick diffusion and extended Langmuir equation, a multi-field coupling mathematical model of migration, displacement and desorption of methane and carbon dioxide in coal seam was established. The effects of different carbon dioxide gas injection pressure and the arrangement of injection and extraction boreholes on improving coalbed methane recovery were numerically simulated. The results show that in the process of carbon dioxide displacing methane, a “methane enrichment area” will appear in the coal seam near the gas injection borehole, and with the increase of gas injection time, the “methane enrichment area” will gradually move to the exhaust borehole until the methane concentration distribution in the coal seam is stable, and the average methane concentration in the coal seam is 56.5% of the original methane concentration. The methane flow rate in the exhaust borehole first decreases, then increases rapidly to a peak, and then decreases slowly to a stable value. In addition, the distance between injection and extraction boreholes has no effect on the methane flow after the methane concentration at the exhaust borehole is stable, but has an obvious effect on the peak value of methane flow and the time of peak value.
为解决某铅锌矿细粒级、高含硫尾砂充填时强度偏低、后期强度劣化的问题,通过对充填材料进行分析,采用粗骨料与全尾砂作为充填骨料进行充填,开展了充填材料配比、强度特性室内试验研究,并根据高硫尾砂特性研发了 CKY充填外加剂.结果表明:全尾砂与粗骨料配比为8:2和7:3时,充填料浆保水性均较好,质量浓度为76％～78％的料浆具有较好的和易性,不发生沉降或有少部分尾砂沉降,适合充填;尾砂含硫量达32％,充填体试块在60 d、90 d龄期时出现不同程度劣化,加入了 2％添加剂后,全尾砂:粗骨料为8:2的充填体前、后期强度增长明显,全尾砂:粗骨料为7:3的充填体前期强度虽未增长,但后期强度增长明显,且未出现强度劣化现象,表明CKY添加剂对于维持充填体强度的效果较好.
