浏阳河隧道爆破振动测试

浏阳河隧道下穿浏阳河,采用爆破法施工。为保证地表建筑物和水下隧道顶板不贯穿上部河道,必须对爆破振动进行监测,并根据爆破监测结果进行爆破施工安全性分析评定。     

楔形掏槽爆破技术在熊洞湾隧道的应用

介绍了熊洞湾隧道开挖施工中所采用的掏槽爆破的施工技术。根据熊洞湾隧道的工程地质情况,对隧道开挖的爆破参数、炮孔布置、装药结构以及起爆网络进行了分析和设计。提出了保证隧道开挖成型质量的施工方案,确保了熊洞湾隧道掏槽爆破取得圆满成功。     

基于PDCA循环的牛角山隧道光面爆破质量控制与技术改进

光面爆破质量直接关系到隧道施工的质量、安全及成本等,牛角山隧道凿岩爆破开挖施工过程中,采用PDCA循环质量管理方法,根据TM隧道断面测量系统采集的断面超欠挖数据,进行现场检查、讨论分析,找出影响光面爆破质量的主要因素,通过制定有针对性的改进措施并监督执行,较好地提高了光面爆破效果,一次循环进尺平均光面爆破合格率达到95%,炮眼残留率达到85%,不仅保证了隧道施工质量,而且降低了施工成本,加快了施工进度,获得了良好的质量效果和经济效益。     

隧道爆破振动对上部高压铁塔的影响分析

结合长湘高速公路李家冲隧道爆破施工,为保证隧道上方高压铁塔安全,采用了"H"型框架梁加固塔基,并采取改变钻爆设计与上台阶核心土尺寸等施工措施,成功将塔基处爆破振动速度控制在2.58 cm/s,在保证高压铁塔安全的同时,有效保证了该工程的快速安全施工,为以后隧道爆破工程中上方较高建筑物或构筑物的保护提供了有益的经验。     

兰青复线虎头崖隧道微振动爆破技术实践

新建兰青复线虎头崖隧道出口段与既有隧道线间距较近，为保证既有隧道正常行车安全，对新建和既有隧道进行支护加固并采用微振动爆破技术施工，同时采用振动测试仪对隧道爆破振动进行监测，根据监测结果对下一次爆破参数进行优化。通过合理选择爆破时差、最大装药量、微差起爆、掘进进尺、预裂爆破等方面的振动控制技术措旌，使该隧道开挖施工爆破中的地面振动速度值控制在安全范围以内，保证，虎头崖隧道开挖作业安全、顺利地进行。     

新柳林河隧道爆破振动监测及分析

结合太兴铁路太静段工程TXXS-1标段新柳林河隧道的实际工程,对新建隧道光面爆破开挖而产生的爆炸振速进行监测与分析,并得到振速预测公式。在施工中,通过及时调整爆破参数来控制爆破振速,保证了隧道掘进施工的安全。     

微差爆破技术在水下爆破工程中的应用

介绍了在水下爆破工程中采用了微差爆破技术,使近距离水下爆破施工保证了码头用岸边建筑物的安全,工程质量满足设计要求,取得了较好的经济效益和社会效益.     

超小净距交叉隧道的爆破振动监测与控制技术

以重庆市高九路至华村立交连接段道路工程的I、J线隧道与嘉华隧道交叉加强段的爆破施工为研究对象,对在空间上形成超小净距交叉隧道工程的爆破震动波监测及控制技术进行探讨.通过对现场大量爆破振动监测数据的回归分析,建立了隧道开挖爆破振动传播的数学模型,确立了其传播衰减规律.根据现场工程实践,选择合理的爆破振动控制技术,使隧道开挖施工爆破时产生的质点振动速度值控制在安全范围内,保证既有公路隧道安全的同时使在建隧道顺利通过.     

复线隧道爆破优化设计与实践

以新风平岭2号隧道复线隧道进口开挖为研究对象,通过在隧道施工爆破过程中对邻近隧道进行现场的振动监测,应用萨道夫斯基经验公式对现场监测数据进行回归分析,控制不同目标、不同间距情况下最大起爆药量,炮眼布置方案等。既有隧道和新开发隧道间采用超前锚杆加固,增强稳定性。通过对振速波形图的分析,找到延时爆破最大振速的段位,降低该段位最大装药量以便降低最大振速,保证邻近隧道振动速度控制在安全范围内,指导后续施工。     

隧道爆破参数优化及振动效应研究

隧道掘进爆破开挖过程中对既有隧道围岩和周围邻近建构筑物有一定的爆破振动危害。采用了上下台阶多断面开挖方法,结合爆破振动监测,分析出隧道爆破振动效应的相关规律。结果表明:合理的掏槽孔爆破形式可有效降低爆破振动峰值,隧道爆破掘进过程,严格控制最大单响药量,采用合理的振动检测手段和检测方法进行现场检测,是确保隧道爆破开挖施工安全的有效方法。     

Current situation and future trend of China rare earth luminescent material industry

<正>Rare earth luminescent material is one of the most important application sectors of rare earths.China enjoys the exceptional advantage to develop rare earth luminescent material for its abundant rare earth resources.After several decades'endeavor,China's rare earth luminescent material industry,headed by rare earth phosphor for lamp and LED and high efficient rare earth energy-saving light source,has been gradually developed into a scale industry.China has become a major production base of rare earth phosphor for lamps and rare earth     

China rare earth market review

正June 1~10,2014Rare earth market remained weak.Quoted price of rare earth products was similar to that in May.There was no sign of recovery in downstream market.The market of NdFeB magnetic materials and phosphor was depressed.Catalyst,polishing powder and ceramic industries remained inactive.Demand from downstream industry was soft.Consumers purchased on their needs.Suppliers had strong intention to sell.Prices of rare earth products     

Annual Report analysis of Chinese rare earth-related listed companies in 2013

<正>Chinese rare earth-related listed companies have published their 2013 annual reports.It can be understood from their reports that production and operation activities of Chinese rare earth-related companies were still heavily affected by macro economy and industrial policies.They basically followed the steps of national economy.In 2013,world economy recovered slowly but the economy     

Market opportunities and challenges for rare earth polishing powder

正1.Status of rare earth polishing powder Rare earth polishing powder with high content of cerium oxide began to replace iron oxide for glass polishing and became one of the key materials in glass polishing process since 1940.Compared with traditional iron oxide,rare earth polishing powder has many advantages,such as fast polishing rate,high polishing quality and long service life.It can achieve good surface quality and improve operation conditions.For example,in lens polishing,the polishing work that cerium     

Baotou Research Institute of Rare Earths developed a new RE alloy preparation technology

正Pyrometallurgy Laboratory of Baotou Research Institute of Rare Earths had independently developed a new preparation technology of rare earth alloy for NdFeB.The alloy can remarkably enhance the coercivity of NdFeB magnet but also evidently reduce the production cost of the magnet.The new master alloy was prepared in the kA pilot-scale electrolytic cell by the independent technology.The rare earth master alloy can be used as the raw material for NdFeB.Compared     

Market and recycling of NiMH battery

<正>Market status and future trend of NiMH battery1.Global market of small NiMH battery Global market size of small NiMH batteries declined year on year since 2011.The trend will continue to 2018,at the rate of 5%to 10%annually.Demand for small NiMH batteries will be stable gradually.Many electrical apparatuses are powered by the built-in lithium battery today,which is the main reason for the shrunk market of small NiMH batteries.But,for some products,small NiMH     

China rare earth market review

正September 1-10,2014 Affected by the National Day holiday,rare earth transaction was stagnant and the market showed a weak steady state.As there was no good news for downstream market,some products with flat demand would likely rally slightly for some time to     

2014 second batch of rare earth quota released

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矿用防爆轴流对旋主要通风机叶片ANSYS模态分析及应用

高效节能矿用防爆对旋主要通风机的叶片是主要通风机运行的关键部件,叶片在运行时不断受到气流的作用力,从而使叶片产生振动,当叶片振动的频率与叶片的固有频率接近时,容易产生共振从而导致叶片的断裂。一旦叶片断裂时,对主要通风机的安全运行产生致命的影响,从而导致矿山、化工等企业发生重大事故,将会产生不可估量的损失。基于有限元分析软件ANSYS,对高效节能矿用防爆轴流对旋主要通风机叶片进行模态分析及产生对应的六阶模态频率,对主要通风机叶片的运行频率、固有频率及产生的共振问题进行了原理分析,并且解决了叶片频率共振的问题,从而为主要通风机叶片结构设计提供理论依据,并对主要通风机叶片的安全运行提供保障。     

2013 NdFeB export analysis

<正>China totally exported nearly 24,000 tonsof NdFeB products during 201 3,including 18,825 tons of permanent magnet,valued USD 1.34 billion at an average price of 71.4 USD/kg;3,277 tons of NdFeB magnetic powder,valued USD 1 01 million at an average price of 30.9 USD/kg;1,334 tons of strip casting ribbon,with total export value of USD 74million at an average price of 55.3 USD/kg;and 586