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王其胜 《卫星电视与宽带多媒体》2006,(3):23-25
印度2005年内批准了10-12颗卫星发射计划印度政府2005年内共批准了在未来4年内发射10-12颗卫星的计划,包括通信卫星INSAT-4A(已发射)、INSAT4B、INSAT4C、GSAT-4(已发射)和GSAT-5,用于地图测绘的先进卫星Cartosat-2,拥有全天候雷达成像能力的微波遥感卫星,海洋研究与服务卫星Oc 相似文献
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随着浅部资源的日渐减少,大部分矿山正转入深部开采,由于深部开采巷道处于高应力的条件下,深部巷道支护,尤其软岩巷道支护成为一大难题。通过在素混凝土材料中加入钢钎维对支护方式进行了改善,SHPB实验装置对添加不同钢纤维体积率的混凝土进行的力学性能测试结果表明,当添加钢纤维的体积率为1%时,钢纤维混凝土的强度增加效果较好,深部软岩巷道支护的实践也有力地证明了这一结论。 相似文献
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Influence of underground water seepage flow on surrounding rock deformation of multi-arch tunnel 总被引:3,自引:0,他引:3
Based on a typical multi-arch tunnel in a freeway, the fast Lagrangian analysis of continua in 3 dimensions(FLAC^3D) was used to calculate the surrounding rock deformation of the tunnel under which the effect of underground water seepage flow was taken into account or not. The distribution of displacement field around the multi-arch tunnel, which is influenced by the seepage field, was gained. The result indicates that the settlement values of the vault derived from coupling analysis are bigger when considering the seepage flow effect than that not considering. Through the contrast of arch subsidence quantities calculated by two kinds of computation situations, and the comparison between the calculated and measured value of tunnel vault settlement, it is found that the calculated value(5.7-6.0 mm) derived from considering the seepage effect is more close to the measured value(5.8-6.8 mm). Therefore, it is quite necessary to consider the seepage flow effect of the underground water in aquiferous stratum for multi-arch tunnel design. 相似文献
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文章在有限元计算模拟地下采场开挖的实际工程设计中,根据岩石破坏与岩体工程整体失稳破坏的含义不同,提出不能将岩石材料的破坏与岩石工程系统的破坏用同样的破坏准则加以判断的观点.运用能量的原理,借助突变理论的方法,推导出了采场开挖前后系统失稳破坏的能量突变准则,通过计算开挖前后能量变化值,以判断采场系统失稳的可能性.通过对国内某铅锌矿的有限元模拟分析,证明所提出观点和判断准则是正确的,具有一定的实用价值. 相似文献
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文章在有限元计算模拟地下采场开挖的实际工程设计中,根据岩石破坏与岩体工程整体失稳破坏的含义不同,提出不能将岩石材料的破坏与岩石工程系统的破坏用同样的破坏准则加以判断的观点.运用能量的原理,借助突变理论的方法,推导出了采场开挖前后系统失稳破坏的能量突变准则,通过计算开挖前后能量变化值,以判断采场系统失稳的可能性.通过对国内某铅锌矿的有限元模拟分析,证明所提出观点和判断准则是正确的,具有一定的实用价值. 相似文献