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- roof rock drilling 顶板岩石钻孔
- Features: rock drilling for opencast mining and quarrying field. 适用于露天矿、采石场开采，用于高低风压潜孔钻机。
- The rock drill is indispensable for digging coal mines. 凿岩机是煤炭采掘不可缺少的工具。
- The roof rock was assumed in the elastic state,established the mechanical model of coal pillar and roof system. 假设顶板岩层处于弹性工作状态情况下,建立了煤柱-顶板系统的力学模型。
- LHS Rock Tools CO.,LTD-Rock tools,Rock drills,Rock drilling ... 辽宁葫芦岛莲花山凿岩钎具有限公司（LHS）生产优批发、莲花山凿岩.
- Forward support bolt combined with roop rock by bolting can play a roll of combined beam,which can prevent roof rock caving immediately after explosion. 超前支护锚杆锚固后与顶板岩石构成一体,这样使超前锚杆形成组合梁作用,放炮后,能够阻止顶板岩石冒落。
- Mini rock drill has been produced based on patented technology for rock drill warm extrusion. 采用钎头壳体温挤压精密成形专利技术生产了小型凿岩钎头。
- From whole to blocky and heavily fractured structure, the abutment stress ahead of working face reduces and the peak value of abutment stress migrates to inside of roof rock mass. 过断层后，顶板岩体中支承压力减小，比无断层存在的情况要低。由于顶板岩体中节理发育程度的不同，顶板岩体变形破坏规律和矿压分布各异。表现为由完整到块裂和碎裂结构，老顶的初次垮落步距、周期垮落步距和冒裂带高度均随着岩体破坏程度的增强而减小；顶板岩体中的支承压力亦由大到小变化，且支承压力峰值位置随着岩体破坏程度的增强向顶板岩体内部转移。
- Products:Air compressor, Genset, Concrete Mixer, Concrete Mixing Plant, Rock Drill For Mining. 产品：空压机，发电机，混凝土搅拌机，搅拌站，搅拌车和钻具
- One of the crucial elements influencing the rock burst is the structure of roof rock stratum, especially the flinty and thick sandstone roof over the coal seam. 顶板岩层结构,特别是煤层上方坚硬、厚层砂岩顶板是影响冲击矿压发生的主要因素之一。
- Fax:0769-22687018 Products:Air compressor, Genset, Concrete Mixer, Concrete Mixing Plant, Rock Drill For Mining. 产品：空压机，发电机，混凝土搅拌机，搅拌站，搅拌车和钻具
- We quickly dragged out sandals and entered the water and only think Liangyi attacks, the fish in the river were hurried panic of the rock drilling. 我们连忙拖掉凉鞋，步入水中，只觉得凉意袭人，溪中的小鱼也被惊的慌忙钻进了石头下面。
- Because their cross sections are almost equilateral hexagons,the equilateral hexagons rock drill steels are regarded as my research objects. 钎杆用中空钢,简称“钎钢”,截面以正六角形和圆形为主,因此本文以正六角形钎杆用中空钢为研究对象。
- Guangdong HeShan Forder rock drill tools factory is a famous privately operated enterprise specialized in research and manufacturing rock drilling equipments and pneumatic tools. 广东鹤山福特尔钎具厂是中国专门从事凿岩工具研究与制造的企业。
- We thus suspected that the collapsed roof rock from one of the two oldest Yellowstone supereruptions must have melted to form the bulk of the magma that was ejected during the younger Lava Creek catastrophe and smaller eruptions since. 我们因此猜测，较年轻的克里克熔岩凝灰岩以及之后的小型喷发，岩浆来源是黄石国家公园两个最古老的超级喷发之一，其崩陷的顶层岩熔成了后来喷发出的岩浆。
- Ideal for vertical installations on earth augers or rock drills. 理想的垂直装配,质量更高。
- She and I can't live under the same roof. 她和我不能住在一起。
- The rock drilling rate, service life and tungsten carbide toothavailability of the series of bits are obviously better than those of chip and button type bits. 该系列钎具凿岩速度、寿命和硬质合金片齿有效利用率均显著优于片状和球齿钎具。
- The rock mass structure can be expressed by rock stratum effect thickness influence coefficient. It is more scientific then using roof rock and sand content in the study of coal seam gas preservation. 研究表明,煤层围岩岩体结构控制了煤层瓦斯的赋存,岩体结构可用岩层效应厚度影响系数来表示,应用这一参数研究煤层瓦斯赋存比用煤层顶板岩性及含砂率更科学。
- The longwall may relax some safety problems, but the other safety problems such as hard roof rock, the colliding and friction of the caved rock each other may be induced or intensified . 但是也可能诱发一些安全问题,如坚硬顶板对支架的冲击、采空区垮落岩石的撞击与摩擦诱发瓦斯事故等。
