超薄型钢结构防火涂料施工技术研究

超薄型钢结构防火涂料的防火涂层厚度不大于3 mm,主要以溶剂型为主,具有很好的装饰和理化性能.重点研究钢结构表面处理方法、防火涂料施工环境以及防火涂料的施工工艺对防火涂料涂装效果的影响,以期对超薄型防火涂料最佳施工工艺的选择提供参考.     

极薄矿脉采矿方法研究与应用

介绍了留矿采矿法在极薄矿脉开采中的构成要素、采准切割和回采工作现状及应用特点,并指出了此采矿方法存在的主要问题及在我国的发展趋势。     

水性超薄型钢结构防火涂料的研制与性能研究

以丙烯酸类乳液为成膜物质,以季戊四醇、三聚氰胺、聚磷酸铵与无机增强填料作为阻燃体系,制备了水性超薄型钢结构防火涂料.采用模拟大板燃烧法对防火涂料的耐火性能进行了研究,系统考察了乳液种类、颜基比以及无机填料对防火性能的影响,确定了无机填料的最佳用量.研究结果表明:以硅丙乳液作为基料树脂,当体系颜基比为3.5以及珍珠岩的添加量为7%时,防火涂料的耐火时间能达到128.7 min;珍珠岩与炭质层的生成具有明显的协同效应,这大大提高了炭质层的强度,而且还表现出显著的隔热效果.     

Rising Masses,Singapore

Rising Masses, a year-long final design thesis undertaken at the Architectural Association (AA) School of Architecture, is for a high-rise building in the centre of Singapore's financial district. It is characterised by an extreme thinness that is intended to heighten the experience of working in such a dense urban context. As Max Kahlen of Dyvik & Kahlen, Architecture, explains, two mathematical-based methods were employed in order to aid the design of such a thin structure. Copyright © 2011 John Wiley & Sons, Ltd.     

Manufacture of Extra-Thin Wall Steel Pipe by LD Cluster Mill

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极薄保护层钻采上覆煤层透气性变化及分布规律

为了分析极薄保护层钻采的卸压保护效果,采用相似模拟和现场试验相结合的研究方法,系统地研究了被保护层卸压前后煤层透气性变化及分布规律。相似模拟试验研究表明,极薄保护层钻采后,被保护层产生卸压膨胀变形,煤层透气性增大,实测煤层透气性系数由3.80m2/(MPa2•d)增大到7.11m2/(MPa2•d)。待上覆煤岩体移动稳定后,由于煤岩体应力逐渐恢复,煤层透气性系数降至5.61m2/(MPa2•d),在保护层始采线前方和停采线后方的一定范围内上覆被保护层透气性比采空区中部大。随着被保护煤层逐渐被压实,煤层透气性有所降低,为了达到最佳的瓦斯抽采效果,必须在保护层钻采的同时进行卸压瓦斯抽采。现场实测极薄保护层钻采后被保护层透气性系数由0.047m2/MPa2•d增加到18.928m2/MPa2•d,提高了403倍。     

近水平极薄矿体采矿工艺研究

近水平极薄矿体由于矿体薄、倾角几乎水平,爆破的矿石难以自溜,导致生产效率低、贫化损失大。为提高矿山生产效率,结合南温河钨矿极薄矿脉开采现状,提出了双侧侧向抛掷爆破采矿法,利用抛掷爆破技术将矿石直接抛入受矿槽内,从而很大程度上提高了生产效率。经现场试验与之前采用的采矿方法对比发现,生产效率明显提高,贫化损失率都可控制在10%以内,极大地提高了矿山的经济效益。     

Pressure relief, gas drainage and deformation effects on an overlying coal seam induced by drilling an extra-thin protective coal seam

Numerical simulations and field tests were used to investigate the changes in ground stress and deformation of, and gas flow from, a protected coal seam under which an extra-thin coal seam was drilled. The geological conditions were: 0.5 meter min-ing height, 18.5 meter coal seam spacing and a hard limestone/fine sandstone inter-stratum. For these conditions we conclude: 1) the overlying coal-rock mass bends and sinks without the appearance of a caving zone, and 2) the protected coal seam is in the bending zone and undergoes expansion deformation in the stress-relaxed area. The deformation was 12 mm and the relative defor-mation was 0.15%. As mining proceeds, deformation in the protected layer begins as compression, then becomes a rapid expansion and, finally, reaches a stable value. A large number of bed separation crannies are created in the stress-relaxed area and the perme-ability coefficient of the coal seam was increased 403 fold. Grid penetration boreholes were evenly drilled toward the protected coal seam to affect pressure relief and gas drainage. This made the gas pressure decrease from 0.75 to 0.15 Mpa, the gas content de-crease from 13 to 4.66 m3/t and the gas drainage reach 64%.     

钻采极薄保护层上覆煤层渗透率演化规律研究

通过数值分析方法及现场工业试验等手段,对钻采近距离极薄保护层上覆煤层渗透率变化规律进行研究,得出钻采极薄下保护层上覆煤岩层渗透率分布特征、被保护煤层渗透变化规律等。研究成果对极薄保护层开采及卸压瓦斯抽采参数优化等具有一定的指导意义。