Research on the width of filling body in gob-side entry retaining with high-water materials

To determine the filling body's width along the gob-side remained roadway which is underneath the gob,the authors analyzed the interaction mechanism between the roof and the supporting body along the remained roadway, based on the elastic thin plate theory of the stope roof. The stress state and mechanical response of the filling body along the remained roadway were studied. Specifically, firstly, the supporting pressure of the coal pillar which is on one side of the gob-side remained roadway was deduced.Also, an equation that is used to calculate the width of the balance area in the stress limit state was acquired. Then, an equation that is used to calculate the roof cutting force on one side of the supporting body was obtained. By using FLAC3D, the authors investigated the displacement field and stress field response laws of rock masses around the roadway with different filling body's widths. The results show that with the filling body's width increasing, the supporting ability of the filling body increases.Meanwhile, the rock mass displacement around the roadway and the filling body deformation decrease.The better the filling body's supporting effect is, the higher the roof cutting force will be. When the filling body's width is larger than 3.0 m, its internal bearing ability becomes stable and the filling body's deformation became non-apparent. Finally, analysis shows that the filling body's width should be 2.5 m.Furthermore, the authors conducted field tests in the supply roadway 1204, using high-water materials and acquired expected outcomes.

Creep Property of Solidifying Backfill Body of High-Water Material

On the basis of the creep test of bigh-water materisl solidifying backfill body(abb. HW body), This paper discusses its creep properties- The visco-elasto-plastic model, which shows the creep properties of HW body, is developed, and the creep contitutive equations are deduced. The visco-elastoplastic model is proved by the experiments and practice.

THE RESEARCH OF RHEOLOGICAL PROPERTIES OF STOWING SLURRY WITH HIGH-WATER MATERIALSOLIDIFYING TAILINGS

High-water material, tailings from goldmine and water are mixed into a new slurry.Testing of rheological properties of stowing slurries A and B is made to determine type and rheological parameters of the slurry. The main factors influencing rheological properties of the slurry are analyzed and the rational concentration and empirical resistance calculating formula of pipe line transportation are presented.

Super energy flows in a waveguide filled with air and left-handed materials

The phenomena of super energy flows are studied theoretically and numerically in a parallel-plate waveguide which is filled with two layered equally-thick different media, i.e. air and specific left-handed materials （LHM） with εr1 = -1/（1 ＋δ） ＋iγ and μr1 = -（1 ＋ δ） ＋ iγ. In this special waveguide, two-directional super-energy flows are excited by a three-dimensional horizontal electric dipole at the same time, which has transmission patterns different from those of two-dimensional source and three-dimensional vertical electric dipole. We also show that the retardation and loss in LHM are sensitive to the amplitude of super power densities, and the dimensions of waveguide determine the propagating modes, which makes super energy flows more practical.

SUPER-THIN COATING MATERIAL FOR HIGH-GRADE HIGHWAY

The road surface of cement concrete in highway is easily cracked and even destroyed due to inhomogeneous subsiding of the road foundation. In this work, a super-thin-coating material is prepared in order to repair the destroyed thin road surface, in which polymers and steel-fiber are added into ordinary concrete to form a steel fiber reinforced polymer-cement-based composite, the composite was successfully used to repair road surface. Microstructure and mechanical properties of the composites are measured and analyzed.

Stability analysis and control technology of gob‑side entry retaining with double roadways by flling with high‑water material in gently inclined coal seam

To ameliorate the defects of insufcient support resistance of traditional roadside flling bodies for gob-side entry retaining(GER),overcome the inability to adapt to the deformation of surrounding rock,and isolate the goaf efectively,a new type of high-water material as a roadside flling body for GER technology with double roadways was proposed.The instability analysis and control technology of GER with double roadways by flling high-water material into a gently inclined coal seam were studied.The basic mechanical properties of the new high-water material were investigated through laboratory experiments,and their main advantages were identifed.The reasonable width of the roadside flling wall of a high-water material was obtained by combining ground pressure observation and theoretical calculations.The distribution characteristics of the stress and plastic zone of surrounding rock of GER after being stabilized by the disturbance of the working face were studied using numerical simulations,and the failure range of GER by flling with high-water material was revealed.Based on this,a coupling control technology of anchor cables and bolts+single props+metal mesh+anchor bolts is proposed.Through the coupling methods of arranging borehole peeping and observing the convergences of surrounding rock,the results demonstrate that GER with double roadways by flling with a 1.8-m-wide high-water material has a good control efect.The above research will play an active role in promoting the application of high-water materials in GER roadside flling.

基于超像素快速模糊聚类的印刷品图像分割方法

针对当前彩色印刷品色差检测过程中效率低、复杂性高等问题,提出了一种基于超像素快速模糊聚类的印刷品图像分割方法(SFFCM)。先用简单线性迭代聚类(SLIC)算法将图像分割为紧密相邻的超像素区域。每个超像素区域被视为一个独立的聚类单元。随后,将模糊C均值聚类(FCM)算法应用于超像素的归属关系计算中,即引入隶属度值,允许超像素归属于多个聚类中心,并通过权衡归属度值来实现模糊聚类。实验结果表明,相对于其他算法,本文方法在保持良好实时性的同时,实现了较好的分割效果,有效平衡了算法复杂度与分割效果之间的关系。

超性能灌浆料微观水化机理与连接性能分析

文章通过微观扫描电镜和灌浆套筒连接件力学性能试验,验证超性能灌浆料微观水化机理与连接性能。SEM测试表明,超性能灌浆料内部形成大量的CH、AFt和C-S-H凝胶,胶凝体系内部密实,可以增强体系耐久性能;AFt形成的骨架抑制体系收缩,可以为后期抗压、抗折强度提供支持。采用套筒损伤试验验证连接件的连接性能,结果表明:灌浆套筒发生的损伤以端部钢筋拉断损伤为主,端部灌浆料有轻微的劈裂现象,但灌浆套筒的约束效应明显,阻止了灌浆料劈裂现象进一步出现;灌浆套筒发生损伤后,套筒内部匀直段和变形段与灌浆料的平均黏结应力均远小于损伤应力,灌浆套筒内灌浆料安全储备度高。

高吸水性树脂对含再生骨料的水泥基材料自收缩性能影响及收缩预测研究

为研究含再生骨料水泥基材料的收缩性能并减小收缩率,利用非接触式自收缩仪探究了高吸水性树脂SAP掺量(0.1%~0.3%)、SAP粒径(30目、60目)对超早龄期、早龄期和长龄期下含再生骨料掺量(0%、50%、100%)水泥基材料自收缩性能影响。结果表明:1)再生水泥基材料的超早期(3 d内)自收缩率可达总收缩率的53.1%~91.6%,且自收缩率的控制效果与再生骨料掺量、SAP掺量、SAP粒径密切相关;2)100%再生骨料可将超早龄期(3 d)和长期(90 d)自收缩率分别提高53%~118%、36.2%~78.5%;3)50%再生骨料掺量下,0.1%~0.3%的SAP掺量范围内可将90 d自收缩率降低32.6%~53.9%,而100%再生骨料掺量下,仅0.3%的SAP才能起到减缩效果;4)SAP目数对自收缩率的削减效果受再生骨料掺量的敏感性高;5)BP神经网络能准确预测不同龄期自收缩率与再生骨料掺量、SAP掺量、SAP粒径的关系,基于此提出了低收缩再生水泥基材料的优化设计策略。

超吸水树脂对高性能水泥基复合材料收缩和水化的影响

本工作基于高原干燥环境下高性能混凝土收缩问题,研究了不同掺量的阴离子型聚丙烯酰胺超吸水树脂(SAP-YF)与商用聚丙烯酸型超吸水树脂(SAP-S)对水泥基材料在干燥环境下收缩性能的影响,结果表明,随着SAP掺量的增大,水泥基材料的自收缩与强度逐渐减小,干燥收缩则无明显变化;在考虑不影响强度及最大程度减缩的前提下,SAP-YF在水灰比为0.20条件下的最优掺量为0.20%,减缩率为28.21%;XRD与TG结果表明在养护至7 d时,掺有SAP的试件组的水化程度和固相组成含量的增幅相比于对照组有较为明显的改善。掺入SAP后,净浆试件基体内部的相对湿度能够维持在有利于胶凝材料水化的环境中,可持续7 d或更长时间,从而加速了胶凝材料的早期水化进程。基于XRD、TG试验与理论研究,建立了干燥环境下含SAP水泥基材料固相组成随养护时间的演变模型,这可为热力学模型计算及高原干燥环境下混凝土配合比设计提供数据支持。

超疏水改性水泥基材料设计及性能研究

【目的】研究纳米二氧化硅和硅氧烷对水泥基材料的超疏水改性效果及其性能影响。【方法】以水泥材料为主体,通过正交试验方法优选改性材料十二烷基三甲氧基硅烷(dodecyltrimethoxysilane,DTES)、纳米二氧化硅(nano-silica,NS)和聚羧酸高效减水剂(polycarboxylate superplasticizer,PCE)的最佳配比,并采用强度试验、水化热测试、水接触角测量和毛细吸水试验评估改性材料对水泥力学性能和疏水性能的作用。【结果】DTES、NS和PCE的最佳质量分数分别为3.00%、1.80%和0.25%;改性水泥试样表面的水接触角高达152.50°,毛细吸水系数降低91%以上,3 d抗折强度、28 d抗压强度分别下降19%、12%。【结论】改性材料的协同作用使水泥基材料表面达到超疏水状态,同时具备良好的抗水渗透性能,其中DTES影响水泥强度,NS对抗压强度和后期抗折强度起增强作用。

巷旁充填留巷顶板结构分析与围岩控制技术

为研究沿空留巷顶板结构特征及其支护技术,基于弹性力学薄板理论,建立了沿空留巷顶板悬板结构模型,推演了两种边界条件下悬板主应力表达式,构建了应力比例系数作为薄板破坏判据,研发了沿空留巷巷内顶板斜拉锚索加强支护、巷旁超高水材料复合支护技术。研究结果表明:锚网索支护沿空留巷过程中实施超前预裂切顶,顶板可形成悬板结构,该结构随上覆顶板运动可形成一对边简支一对边自由和一对边固支简支一对边自由两种悬板形式;在矿山压力作用下两种悬板破坏部位不同,可以此作为布置顶板斜拉锚索的依据;顶板斜拉锚索对悬板起悬吊和水平挤压作用。现场试验结果证明了理论分析的可靠性。

煤气化渣替代矿渣制备超硫酸盐水泥的可行性研究

煤气化渣(CGS)富含硅、铝元素,具备作为胶凝材料前体的潜力,但其颗粒形态粗糙,活性较低。为了解决CGS活性低、利用难等问题,利用CGS部分替代矿渣(BFS),探究CGS替代BFS制备超硫酸盐水泥(SSC)的技术可行性,并借助傅里叶红外光谱、X射线衍射仪、热重分析仪、扫描电子显微镜及能谱仪等微观测试技术对SSC水化产物的微观结构进行表征分析。结果表明,CGS作为制备SSC的原料,能提供初始水化所需要的硅、铝元素,驱动SSC发生水化反应。随着CGS掺量的增加,SSC胶砂的抗压强度呈逐渐减小趋势,而抗折强度受影响较小。CGS的最佳掺量为20%(质量分数),在此掺量下胶砂试样的28 d抗折强度最大,抗压强度也达到43.9 MPa。SSC的水化产物主要是水化硅酸钙、水化硫铝酸钙等凝胶。研究结果显示CGS部分替代BFS完全可用于制备SSC。

堆石料缩尺效应试验及其数值模拟

堆石料的缩尺效应影响其力学参数的准确性。对某堆石料开展的超大型三轴(试样尺寸分别为直径500mm,高1000mm最大粒径为100mm)和大型三轴(直径300mm,高700mm最大粒径为60mm)剪切试验,用PFC3D对试验过程进行模拟,进一步探索缩尺对堆石料应力-应变、泊松比和弹性模量的影响。结果表明:大型三轴试验所得的粘聚力小于超大型三轴,内摩擦角则大于超大型三轴;相同围压下,大型三轴试验率先到达破坏的峰值应力,且比超大型三轴的峰值应力高;数值试验能较好地再现三轴试验剪切过程,也为堆石料的缩尺效应试验研究提供了简便方法。

高海拔地质复杂地区喷射混凝土超早强材料应用研究

将纳米早强功能材料、增强型无碱速凝剂及混凝土稳态保塑剂进行有机结合,开发了高海拔地质复杂地区喷射混凝土超早强材料,以解决高海拔地质复杂地区喷射混凝土的超早强性能与工作性能保持、长龄期强度增长的矛盾。研究水胶比、减水剂掺量、纳米早强功能材料、增强型无碱速凝剂及混凝土稳态保塑剂对喷射混凝土的工作性能及抗压强度的影响,通过水化热和水化产物形貌测试探究了其超早强性能和工作性能保持的作用机制,并在某工程进行了工程应用评价。结果表明,8h, 24h和28d的抗压强度分别达到11.9,25.6,53.3MPa。

不同结构体系及材料对超高层建筑结构造价成本的影响研究

文中以贵州省贵阳市某综合楼为例,就结构体系及结构材料对超高层建筑结构经济性的影响进行研究。结果表明,结构体系方面,框架核心筒的单方造价最低,为934元/m^(2),筒中筒结构体系单方造价与之相比增加39.8%,框筒结构体系单方造价与之相比增加53.7%。结构材料方面,普通钢筋混凝土单方造价最低,为1187.2元/m^(2),其次为型钢混凝土1481.4元/m^(2),最高为钢管混凝土1901.1元/m^(2);综合考虑材料的力学性能及经济效益,型钢混凝土性价比较高。因此,最终确定结构体系为框架-核心筒结构体系,材料类型为型钢混凝土。

大型击实与超大型击实对掺砾土料压实度的影响比较分析

在两河口水电站大坝填筑工程的背景下,通过对比分析掺有砾石土料的压实特性,进行大型打实和超大型打实两个方面的分析。通过实验设计和资料收集,对不同击实条件下的土体压实度进行了分析,并对大块击实对掺有碎石的土体压实度的影响进行探讨。分析成果能提供基础数据,为填方建筑质量控制提供技术保障,促进经济效益的提高。此项分析在技术改进、填筑工程实践等方面具有指导意义。

超高水材料老巷注浆加固技术的研究和应用

超高水材料是近年来发展起来的一种无机注浆充填材料,具有凝固时间短、早期强度高、流动性好等特点,超高水材料注浆充填可以将老巷内的空间全部充实,防止有害气体集聚及煤层自燃,同时充填体可与围岩共同承受工作面回采时的超前应力。为了保证回采期间过老巷的安全问题,防止有毒有害气体溢出,东庞矿西庞井提出超高水材料老巷注浆加固技术的研究和应用,通过对东庞矿西庞井在回采期间对老巷的注浆加固,确保了工作面在过老巷期间的正常回采,保证了矿井产量,并取得了良好的应用效果。

京唐3号高炉原燃料质量劣化下的提产创效措施

对京唐3号高炉原燃料质量劣化下的提产创效措施进行了总结。2021年7月,由于焦煤和秘鲁球团矿粉资源紧缺,原燃料质量劣化,3号高炉炉况稳定性减弱,炉墙水温差波动增大,铁水[Si]含量呈下降趋势。通过采取改善原燃料质量、优化装料制度、改善送风制度、稳定铁水[Si]、强化出铁管理等措施,尤其是装料制度坚持“打开中心、稳定边沿,稳定中心、照顾边沿”原则,炉况稳定性明显增强,日产量逐步提高。2022年4月,3号高炉焦比283.9kg/t,燃料比494.8kg/t,日产量12963Vd;5月,焦炭负荷达到6.01,利用系数达到2.40V(m^(3)·d)以上。

气凝胶材料隔热应用研究进展

气凝胶是一种具有高孔隙率、高比面积、低密度与低热导率的超级隔热材料,有着传统隔热材料无法比拟的隔热性能.通过文献调研,简要介绍了气凝胶的制备方法与隔热机理,归纳总结了气凝胶在航空航天、建筑、织物与新能源汽车动力电池领域的隔热应用,并对气凝胶的局限性和发展做出了总结和展望,以期对后续的相关研究提供帮助.