Effect of Blast-Induced Vibration from New Railway Tunnel on Existing Adjacent Railway Tunnel in Xinjiang, China   总被引：1，自引：1，他引：0  

Qingguo Liang  Jie Li  Dewu Li  Erfeng Ou 《Rock Mechanics and Rock Engineering》2013,46(1):19-39

The vibrations of existing service tunnels induced by blast-excavation of adjacent tunnels have attracted much attention from both academics and engineers during recent decades in China. The blasting vibration velocity (BVV) is the most widely used controlling index for in situ monitoring and safety assessment of existing lining structures. Although numerous in situ tests and simulations had been carried out to investigate blast-induced vibrations of existing tunnels due to excavation of new tunnels (mostly by bench excavation method), research on the overall dynamical response of existing service tunnels in terms of not only BVV but also stress/strain seemed limited for new tunnels excavated by the full-section blasting method. In this paper, the impacts of blast-induced vibrations from a new tunnel on an existing railway tunnel in Xinjiang, China were comprehensively investigated by using laboratory tests, in situ monitoring and numerical simulations. The measured data from laboratory tests and in situ monitoring were used to determine the parameters needed for numerical simulations, and were compared with the calculated results. Based on the results from in situ monitoring and numerical simulations, which were consistent with each other, the original blasting design and corresponding parameters were adjusted to reduce the maximum BVV, which proved to be effective and safe. The effect of both the static stress before blasting vibrations and the dynamic stress induced by blasting on the total stresses in the existing tunnel lining is also discussed. The methods and related results presented could be applied in projects with similar ground and distance between old and new tunnels if the new tunnel is to be excavated by the full-section blasting method.  相似文献   

天水第三系泥岩地球化学特性研究——以梁家山隧道开挖岩样为例     

欧尔峰  梁庆国  鲁得文  孙文 《地球科学进展》2013,28(3):398-406

天水地区第三系地层属于西秦岭甘肃群,梁家山隧道洞身穿越天水盆地第三系泥岩,为确定隧道围岩的地质特性,进行了泥岩样品的地球化学成分与矿物成分测试。将梁家山隧道泥岩的测试结果与天水秦安县下山剖面泥岩的结果进行对比分析和相关分析。结果表明:二者之间存在较好的相关性,能够描述梁家山隧道泥岩的地层岩性、区域地质背景及其演化等工程地质特性,为进一步研究天水盆地的物质组成、风化特征、沉积环境和构造背景提供依据。同时也为利用隧道工程修建研究相关地学问题提供范例和基础数据。  相似文献   

Control strategies and experimental verifications of the electromagnetic mass damper system for structural vibration control     

张春巍  欧进萍 《地震工程与工程振动(英文版)》2008,7(2):181-192

The electromagnetic mass damper （EMD） control system, as an innovative active control system to reduce structural vibration, offers many advantages over traditional active mass driver/damper （AMD） control systems. In this paper, studies of several EMD control strategies and bench-scale shaking table tests of a two-story model structure are described. First, two structural models corresponding to uncontrolled and Zeroed cases are developed, and parameters of these models are validated through sinusoidal sweep tests to provide a basis for establishing an accurate mathematical model for further studies. Then, a simplified control strategy for the EMD system based on the pole assignment control algorithm is proposed. Moreover, ideal pole locations are derived and validated through a series of shaking table tests. Finally, three benchmark earthquake ground motions and sinusoidal sweep waves are imposed onto the structure to investigate the effectiveness and feasibility of using this type of innovative active control system for structural vibration control. In addition, the robustness of the EMD system is examined. The test results show that the EMD system is an effective and robust system for the control of structural vibrations.  相似文献   

Design approaches for active, semi-active and passive control systems based on analysis of characteristics of active control force   总被引：1，自引：0，他引：1  

Jinping Ou  Hui Li 《地震工程与工程振动(英文版)》2009,8(4):493-506

In this paper,the characteristics of forces in active control systems connected to adjacent levels of a building are analyzed.The following characteristics are observed:(1) active control can provide signifi cantly superior supplemental damping to a building,but causes a small frequency shift;(2) the linear quadratic regulator(LQR)-based control force is composed of an elastic restoring force component and a damping force component,where the damping force is almost identical to the total control force,howev...  相似文献   

盆地形成及成矿与地幔流体间的成因联系   总被引：11，自引：0，他引：11  

杜乐天  欧光习 《地学前缘》2007,14(2):215-224

文中共讨论以下5个问题:(1)盆地起源于幔壳溃变和膨隆,后者是地幔流体(超临界态(>375℃)HACONS流体,简称幔汁)上涌、渗入、交代、富化、致熔的产物。地幔流体造成油气盆地深部的高热流、异常超高压、伊利水云母化、硅化和地层有机碳的加氢成油作用。(2)盆地成矿可分两大阶段,先是沉积时的同生成矿;地层沉积后还有众多的后生成矿。两者组成“盆地矿套”(杜乐天,2002)。成矿无论同生还是后生,其分布均受断裂控制,都和地幔流体活动有关。(3)黑色页岩的实质是碳-硅-泥三元岩系,和热液成矿中的碳酸盐-硅质-泥质蚀变三元完全相当。此类岩系中总是有几十种亲壳亲幔亲气元素的特殊富集。奇异的是,石油、油页岩、沥青及砂岩型铀矿彼此有完全类似的继承性元素特殊富集。此等元素群不可能都是来自盆地之外蚀源区岩体的风化。研究证明,相当多的元素是地幔流体携带上来的。(4)盆地地层中广泛发育由地幔流体衍生的热液作用。(5)盆地实质上是气盆,全盆地排气。许多气田是地幔流体排气形成的。沙漠(原地型)和天然气田的共生很值得注意,两者皆源于地球强烈排气,导致地下和大气增温,过度蒸发,不易降雨,长期干旱而形成沙漠。  相似文献   

莺—琼盆地1号断裂带含烃热流体活动初探   总被引：3，自引：1，他引：2  

孙玉梅  欧光习 《岩石学报》2000,16(4):687-694

１号断裂带是莺－琼盆地油气勘探的重点地区之一,有机包裹体研究有助于追踪油气及热流体活动的痕迹,为油气运聚成藏提供地球化学依据,通过包裹体薄片镜下观察,均一温度和盐度测试,认为工区内发育五种类型的有机包裹体：（１）液态烃包裹体;（２）气流态烃包裹体;（３）气态烃包裹体;（４）含烃ＣＯ２包裹体;（５）烃子矿物包裹体,含烃ＣＯ２包裹体一般与气态烃共生,含烃子矿物包裹体既无液态烃共生又与气态烃共生,包裹体  相似文献   

平南幔源包体中橄榄石的显微构造研究及其意义   总被引：1，自引：0，他引：1  

孔华  马芳  金振民  欧新功 《地球科学》2001,26(1):7-12

平南玄武岩中的尖晶石二辉橄榄岩包体的平衡温度为930~980℃, 平衡深度为59~74km, 包体中橄榄石的扭折带滑移系多为(010) [100], 但也有(001) [100]的滑移系类型; 斜方辉石的滑移系为(100) [001], 它们均为高温低应变速率下的滑移系, 说明该区的上地幔主要是在高温低应变速率条件下经历了塑性变形作用.橄榄石位错组态多样, 有自由位错、位错壁、位错弓弯、缠结、{110}滑移带, 反映了上地幔的塑性变形特征.根据位错壁的大小估算, 上地幔差异流动应力为24.5~42.1MPa, 流动速率为2.93×10-17~8.36×10-16s-1, 有效粘度为1.72×1023~2.80×1024 Pa·s, 特征与中国东部新生代上地幔较为一致, 反映同处于拉张环境.   相似文献   

区域性热带气旋暴雨短期预报系统在MICAPS系统上的移植     

梁飞燕  欧坚莲  潘习元 《气象研究与应用》1999,20(3):56

利用MICAPS系统上的实时报文资料,以物理量场诊断为动力相似的主要依据,综合热带气旋移动路径及登陆范围来订正,以人机结合方式完成梧州及贺州地区的热带气旋暴雨24h落区预报工具在MICAPS系统上的移植,直观形象地显示预报结果。该工具利用1979～1980年7～9月、1995年7～9月3a的热带气旋实例进行试报,1997～1998年7～9月试运行,均取得较好的预报效果,目前已可以在后汛期台风季节中投入准业务试用。  相似文献   

内蒙古东部半干旱草原残丘景观区铜多金属元素表生地球化学异常特征及其评价指标体系的构建   总被引：4，自引：1，他引：3  

王瑞廷  欧阳建平  蒋敬业 《矿产与地质》1999,13(6):348-353

分析了研究区内钙积层、风成沙等制约因素对铜多金属元素表生地球化学异常发育的影响,总结了该类特殊景观条件下铜多金属元素表生地球化学异常特征及其在垂向和侧向上的迁移规律。在此基础上,构建了该类景观区铜多金属元素的表生地球化学异常评价指标体系  相似文献   

A new approach to GPS ambiguity decorrelation   总被引：13，自引：1，他引：12  

L. T. Liu  H. T. Hsu  Y. Z. Zhu  J. K. Ou 《Journal of Geodesy》1999,73(9):478-490

Ambiguity decorrelation is a useful technique for rapid integer ambiguity fixing. It plays an important role in the least-squares ambiguity decorrelation adjustment (Lambda) method. An approach to multi-dimension ambiguity decorrelation is proposed by the introduction of a new concept: united ambiguity decorrelation. It is found that united ambiguity decorrelation can provide a rapid and effective route to ambiguity decorrelation. An approach to united ambiguity decorrelation, the HL process, is described in detail. The HL process performs very well in high-dimension ambiguity decorrelation tests. Received: 9 March 1998 / Accepted: 1 June 1999  相似文献