岩体灌浆检测方法及其适用性评价   总被引：2，自引：2，他引：2  

施建新 《水文地质工程地质》2002,29(4):70-73

在工程岩体灌浆检测中，除采用孔内声波法外，尚有孔中电视、孔中流量测试和孔间地震波CT等方法，本文简单介绍了各方法的原理，并对其特点、局限性和适用性作出具体评价，同时给出几个实例供相关工程参考。  相似文献   

多层建筑基础隔震的减震效果分析     

雷静雅  汪芳  罗登贵  何涛 《大地测量与地球动力学》2007,27(Z1):71-73

介绍基础隔震结构的工作原理和两种计算模型，结合工程实例采用时程分析法和Matlab程序模拟计算结构隔震和不隔震时的顶层响应，计算结果表明多层建筑采用基础隔震可以有效地降低结构的地震反应。  相似文献   

煤层孤岛工作面冲击矿压的防治实践     

王富有 《中国煤田地质》2007,19(2):41-43

木城涧矿450水平西四采区三槽东一壁工作面发生的几起冲击矿压事故,与其工作面开采深度、所处地质构造部位、呈孤岛开采状态有关.工作面煤样和顶板冲击倾向性测试结果表明,该煤层属于高冲击倾向性煤层,具有发生冲击矿压的能力.根据产生冲击矿压的原因和特点,采用电磁幅射进行冲击矿压预测预报、爆破卸压进行治理的措施,通过了冲击矿压危险区.  相似文献   

某港口工程地基处理中的强夯影响范围研究   总被引：1，自引：0，他引：1  

程祖锋  孙秀娟  谌会芹 《工程地质学报》2007,15(1):88-91

强夯法是地基处理的一种常用方法,而确定强夯影响范围是强夯法应用的关键。结合某港口工程地基处理的实测资料,分析强夯振动在深度和广度上的影响范围,进而得出振动的位移、速度、加速度随距夯击点距离增大而逐渐衰减的曲线关系式。  相似文献   

区域非稳定动力学环境下的岩体松动效应     

马润勇  彭建兵  周立新  门玉明  毛彦龙  李喜安 《工程地质学报》2007,15(4):475-482

区域非稳定动力学环境下,长期的构造变形、重力卸荷以及地震动力作用的共同影响,可以导致岩体发生大范围变形、松动。松动岩体内发育大量的软弱结构面,且表现出整体破碎、松弛严重、透水强烈,张性节理裂隙发育、地表裂缝较发育、岩体地震动力破坏信息反映明显等特征。岩体的变形松动可以分为卸荷变形松动、倾倒变形松动、顺层滑移松动、断层控制松动、节理裂隙控制松动等5种模式。岩体的物理振动试验结果表明,地震动力是造成岩体松动的主因。数值模拟结果表明,在单纯自重应力影响作用下,松动岩体不会出现大面积的失稳破坏现象,但在地震动力作用下,松动岩体会发生大面积屈服破坏。  相似文献   

Studies on the effect of burden width on blast-induced vibration in open-pit mines     

Önder Uysal  Ercan Arpaz  Mehmet Berber 《Environmental Geology》2007,53(3):643-650

This study concerns the correlation between burden and blast-induced vibrations in open-pit mines. For this purpose, two different mines were studied. In these mines, the vibrations caused by explosions at burdens having widths ranging from 3 to 14 m were measured from various distances. From the results, it was found for these cases that burden width has a significant impact on vibrations. Consequently, it was proven that vibrations decrease as burden increases.  相似文献   

砂体非均质性是铀成矿的关键因素之一--鄂尔多斯盆地东北部铀成矿规律探讨   总被引：26，自引：4，他引：22  

焦养泉  陈安平  杨琴  彭云彪  吴立群  苗爱生  王敏芳  徐志诚 《铀矿地质》2005,21(1):8-15

在鄂尔多斯盆地东北部,铀成矿与直罗组底部砂体的非均质性关系密切。砂体非均质性主要表现在平面和垂向上,其中,砂体平面非均质性可以通过砂分散体系来表征,而垂向非均质性则可以通过隔挡层和沉积物粒度来表征。在平面上,铀成矿主要分布于辫状河沉积体系向辫状河三角洲沉积体系过渡的辫状分流河道一侧,最佳成矿区则位于辫状分流河道砂体的频繁分岔处和从无隔挡层到隔挡层突发区的河道砂体边缘,且随着隔挡层数量和厚度的增加,铀成矿几率和品位逐渐降低;在垂向上,隔挡层的存在可以导致多个垂向序列单元、层间氧化带和铀矿卷头的发育。统计发现,中砂岩和细砂岩是铀成矿的最佳载体,所以在每个垂向序列单元中,铀矿通常位于辫状分流河道砂体的中下部。铀的成矿机理一方面可能是砂体非均质性通过对成矿流体运移状态的影响进而实现对铀成矿的控制,另一方面可能与沉积环境相变导致还原性物质的增加有关。通过砂体非均质性研究而总结的铀成矿规律是进行铀成矿空间定位和预测的基础。  相似文献   

The buckling and vibration of tube-stiffened axisymmetric shells under external hydrostatic pressure   总被引：1，自引：0，他引：1  

C. T. F. Ross  J. Etheridge 《Ocean Engineering》2000,27(12)

The paper reports on a theoretical and an experimental investigation into the buckling and vibration of prolate hemi-ellipsoidal tube-stiffened domes under external water pressure. The theoretical analyses were via the finite element method, where both the fluid and the structure were modelled with finite elements. The dome was modelled with a varying meridional curvature element and with eight displacement degrees of freedom and the water was modelled by solid annular elements where each element had eight pressure degrees of freedom in its cross-section. Comparison was good between experiment and theory.  相似文献   

Geomorphic controls of perched groundwater interaction with natural ridge-top depressional wetlands     

Jonathan M. Malzone  Ethan G. Sweet  Addison C. Bell  Gilbert L. Minzenberger 《水文研究》2020,34(4):1089-1100

Geographically isolated wetlands (GIWs) are commonly reported as having hardpan or low hydraulic conductivity units underneath that produce perched groundwater, which can sustain surface water levels independently of regional aquifer fluctuations. Despite the potential of GIW-perched aquifer systems to provide important hydrological and ecological functions such as groundwater storage and native amphibian habitat, little research has studied the hydrologic controls and dynamics of these systems. We compared several ridge-top depressional GIW-perched groundwater systems to investigate the role of watershed morphology on hydroregime and groundwater-surface water interaction. Ridge-top depressional wetlands in the Daniel Boone National Forest, Kentucky were chosen because they offer natural controls such as lack of apparent connection to surface water bodies, similar climate, and similar soils. Three wetlands with different topographic slopes and hillslope structures were mapped to distinguish key geomorphic parameters and monitored to characterize groundwater-surface water interaction. Wetlands with soil hummocks and low upland slopes transitioned from infiltration to groundwater discharge conditions in the spring and during storm events. The magnitude and duration of this transition fell along a continuum, where higher topographic slopes and steeper uplands produced comparably smaller and shorter head reversals. This demonstrates that ridge-top GIW-perched groundwater systems are largely sensitive to the runoff-recharge relationship in the upland area which can produce significant groundwater storage on a small-scale.  相似文献   

Fundamental behavior of Vortex Self Induced Vibration (VSIV)     

《Applied Ocean Research》2014

An experimental facility has been designed to study the transverse response of the vortex-induced vibration of a fully submerged horizontal cylinder under the influence of vertical harmonic oscillating motion. The study aims to analyze the vortex self-induced vibration (VSIV) phenomenon which occurs on steel catenary risers (SCR) connected to floating platforms in the deep offshore. These vibrations occur in the absence of a current due to the self-motion of the body caused by a source afar. The experiments were conducted in a tank at the LOC/COPPE/UFRJ (Laboratory of Waves and Current of COPPE, Federal University of Rio de Janeiro). The amplitude and frequency of transverse motion are calculated for various Keulegan-Carpenter numbers and reduced velocities. Thanks to both the use of recent instrumentation and very low damping pneumatic bearing, the paper complements the pioneering work by Sumer and Fredsoe (1988) by exhibiting for the first time the trajectories of the VSIV motion. These are classified based on their different configurations such as oval-shape, eight-shape, etc. The Particle Image Velocimetry (PIV) tests are used to study the behavior of the flow around the cylinder during different trajectories of VSIV motion.  相似文献