瑞丰煤业超高水材料充填技术研究与应用

超高水材料充填是工作面采空区充填方式之一,论文针对瑞丰煤业1612工作面的基本情况,设计了超高水材料混合充填技术与工艺,系统地介绍了充填技术装备与组成,成功地实现了工作面运输巷沿空留巷.观测结果表明,采用高水材料充填技术,可有效避免地面沉降,保证充填效果,实现煤炭资源的最大回收.     

膨润土-砂混合型缓冲/回填材料研究现状与展望

高放废物处置中,膨润土-砂混合型缓冲/回填材料力学性质的研究对高放废物地下处置库的建设具有重要意义。在总结国内外缓冲/回填材料研究现状和成果基础上,该文认为试验仪器的研制、开发添加不同材料的混合材料、考虑高温-高压-高吸力条件的试验研究、模型试验、热-水-力-化耦合模型的建立和数值分析是今后一段时间内混合型缓冲/回填材料研究的重点。     

Rapid diffusion bonding of WC-Co cemented carbide to 40Cr steel with Ni interlayer: Effect of surface roughness and interlayer thickness

WC-Co cemented carbides were rapidly diffusion bonded to 40Cr steels with pure Ni as interlayers by utilizing plasma activated sintering (PAS). The bonding was carried out at 750 °C for 13 min under a pressure of 40 MPa. It was found that the roughness of the initial surfaces still plays an important effect on the microstructure and mechanical behavior of the joints diffusion bonded by PAS irrespective of the electric current applied during bonding. The adoption of smoother original surfaces was significantly favorable to eliminate the interfacial interstices and microvoids. Correspondingly, the shear strength of the diffusion bonded joints increased with decreasing surface roughness. Additionally, the effect of interlayer thickness on the shear strength of the joints was also evaluated, and the results showed that the strength decreased sharply when thicker interlayer was employed. A maximum value of shear strength, 293.07 MPa, was obtained when the original surfaces was ground with P1200 grit SiC paper and at the same time 50 µm thick interlayer was used. In this case, the fracture initiated and run predominantly along the bonding interfaces instead of in the WC-Co substrate.     

Tool life and wear mechanism of WC–5TiC–0.5VC–8Co cemented carbides inserts when machining HT250 gray cast iron

Cutter development has drawn a lot of attention for cast iron machining in recent years. In this study, a special cemented carbide of WC–5TiC–0.5VC–8Co (WTVC8) was used for a comprehensive HT250 gray cast iron machining test. Compared with the baseline plain WC–8Co(WC8) carbides, WTVC8 shows significantly higher tool life under the same cutting conditions due to significantly higher hardness and red hardness. The worn flank face observation shows that adhesion wear and oxidation are the main wear mechanisms and there is no apparent chipping/breakage and abrasion wear for both WTVC8 and WC8. Based on Taylor's equation, the accurate tool life models for both WTVC8 and WC8 have been constructed, which shows clearly that cutting speed has the most significant effect on tool life, followed by depth of cut and feed rate. The tool life models can serve as a quantified guidance for cutting performance optimization.     

高庙子膨润土及其混合材料导热性能研究

导热性能是高放废物地质处置库缓冲/回填材料的重要性能之一。采用瞬变平面热源法,研究了我国高放废物地质处置首选缓冲/回填材料高庙子膨润土,及以其为主料,添加不同含量石英砂、北山花岗岩碎屑组成的混合材料的导热性能。分析了添加剂种类和含量、干密度、饱和度等因素对导热系数的影响。研究结果表明:高庙子膨润土及其混合材料的导热系数、热扩散系数都随干密度和含水量的增大而增大;石英砂、北山花岗岩碎屑能够不同程度提高膨润土的导热系数,石英砂的作用优于北山花岗岩碎屑;饱和度对添加剂发挥其提高缓冲/回填材料导热性能的作用影响明显,饱和度越高,添加剂的作用越显著。     

Investigation report of geotechnical disaster on river area due to typhoon landfall three times on Okhotsk region,Hokkaido, Japan

For one week from August 17 to 23, 2016, three consecutive typhoons made landfall in Hokkaido for the first time on record. These typhoons and the front they stimulated brought record-breaking torrential rain over the eastern part of Hokkaido. To investigate the damage to grounds and rivers resulting from this rainfall, the Japan Society of Civil Engineers (JSCE) and the Japanese Geotechnical Society (JGS) formed a disaster research group to conduct an investigation. This report provides the results of the investigation into damage to the grounds of areas along the Tokoro River of the Okhotsk region, Hokkaido, that suffered from this tremendous and diverse disaster. Specifically, the report describes the situation of the levees which were broken and eroded by the overflowing water, the shape of the levee bodies, the levee body soil properties examined by observation of the sections, as well as the occurrence of sand boiling and air blows. The washout of road embankments as well as damage to road bridge mounting fills and abutment backfills were also investigated. The investigation has demonstrated the need to clarify the resistance of the abutment backfills and levee bodies to flowing water as well as the geotechnical predominant factors in order to clarify the mechanisms behind erosion and washout, the need to review new measures that allow for the scale of sand boiling and resultant changes in levee body stability, and the fact that the existing embankments were able to temporarily suppress the flooding water which had spilled over from the river. Furthermore, although it has been identified that the findings of a study on an embankment washout associated with a tsunami can be applied to measures taken against the overflowing water, it has also been found necessary to clarify the predominant geotechnical factors using model tests and to use a more sophisticated analytical approach to establish a geotechnical stability review as soon as possible in order to prevent the levees and embankments from being eroded and washed out due to overflowing water.     

特大型采场充填体单轴压缩条件下的力学性能

对安庆铜矿特大型采场不同配比的充填体进行无侧限单轴抗压强度试验，分析单轴抗压强度、平均杨氏模量、泊松比力学性质的变化及其规律，为特大型矿柱的开采提供前期的数据准备。结果表明，随水泥含量增多，充填体强度基本呈线性增大；平均抗压强度提高百分率随灰砂比的提高而变小；充填体的平均峰荷应变随水泥含量增加而逐渐增大；在从低配比（1：10）向高配比（1：8）转变的过程中，平均杨氏模量有一个较大的波动；充填体的泊松比随灰砂配比的变化不大。     

神经网络在膏体充填质量模型中的应用

煤矿膏体充填质量受多因素影响,且具有非线性特性,用数理统计的方法直接建立充填质量模型很困难。为了减少试验次数、降低试验费用,通过神经网络建立的膏体材料充填质量模型明显优于传统的回归分析法,利用膏体充填材料塌落度与主要影响因素浓度、胶结料用量、细集料用量的关系模型,可以有效预测膏体充填材料的塌落度。     

减水剂对充填料浆强度和流动性的影响

为了提高全尾砂胶结充填料的强度流动性，在其中分别添加ＹＪ－２型和ＦＤＮ高效型两种减水剂进行对比试验，并对试验结果进行了分析。指出，加入适量的ＹＪ－２型减水剂，对全尾砂胶结充填料的２８天强度和流动性均有改善。     

弱胶结砂层突涌机理及预测研究

第三纪和晚侏罗时期沉积的弱胶结粉细砂层在我国东北，西南地区有广泛的分布。以东北某矿区为例，根据我国矿山存在的井下砂层突涌的现象，利用室内模拟试验，探讨了弱胶结砂层在井下形成突水涌砂的机理，为预测，防止该类事故的发生提供理论依据。