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新型数据采集分析系统及其在工程振动中的应用 总被引:4,自引:0,他引:4
本文介绍了针对地震工程和土木工程实验的需求而开发的数据采集分析系统(DAQ-PI-32,VI-BAN2.40)的功能、原理及使用方法。该系统具有通道多(16-32)、精度高(16Bit分辨率)、动态范围大等特点。配套软件VIBAN2.40的功能基本涵盖了振动实验、振动监测、结构及构件力学性能实验等对数据处理的需求,主要功能包括FFT分析、加窗、滤波、功率谱、反应谱、传递函数、相关分析、倒谱以及场地谱比(H/V)等。该系统的主要特点是在窗口操作界面下,实现信号的快速浏览和简易快速谱分析,通过VIBAN2.40可实现数据分析与绘图同步完成,大大提高了工作效率。该系统为地震和工程振动工作者提供了强有力的工具。 相似文献
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多点输入下大跨结构反应谱分析方法研究进展 总被引:4,自引:0,他引:4
在大跨度结构的抗震研究领域,多点输入反应谱方法因其形式简洁、物理意义明确、应用方便等优点而获得了广泛重视和迅速发展,并已在一些重大工程项目的抗震分析中得到了应用。本文首先详细阐述了近年来国内外多点输入反应谱分析方法的研究现状;然后介绍了多点输入反应谱法的应用情况,包括基于该方法进行的大跨度结构地震反应分析和抗震可靠度分析;最后,提出了今后研究中一些需要进一步解决的问题。 相似文献
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研究直立式加筋土挡墙抗震性能时,采用的NCMA方法未全面运算其墙外功率,抗震性能分析结果存在较高偏差。采用极限分析的方法对直立式加筋土挡墙破坏模式展开极限分析,得到该挡墙运动极限表达式。根据运动极限表达式,对一实例墙体计算出此挡墙外功率(包括土重所做的外功率和地震作用所做的外功率),分析其抗震性能。实验结果表明,计算得到直立式加筋土挡墙各层筋材最大外功率分别为18.5 kN·m和20 kN·m,与实际最大外功率18 kN·m差距不大,说明该方法的抗震性能分析与实际情况相符,具有应用性。 相似文献
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基于Matlab的GUI开发环境,采用三仪器法设计地震计自噪声可视化软件,通过对3台地震计同背景同时段原始波形数据进行去均值、去趋势值等一序列数据处理,并运用Welch平均周期法计算噪声功率谱密度,最终绘制完成自噪声功率谱密度曲线。选取山东省临沂市马陵山比测基地作为软件测试地点,以2组各3套地震计(STS2.5、BBVS-120地震计)观测系统作为测试样本,进行地震计自噪声分析,结果发现,STS2.5和BBVS-120型地震计UD向自噪声功率谱曲线在0.04—2 Hz频带内均低于NLNM,表明地震计噪声性能良好,从而验证了软件的可行性与准确性。 相似文献
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传统基于瑞典法的边坡加固抗震性能参数分析,通过建立强度参数与临界滑动面对应关系完成推导,由于因荷载过大,边坡建筑物抗震性能降低,准确率不高等问题,提出新的边坡加固抗震性能参数分析方法,对边坡加固的抗震性能参数进行分析,更好地通过加固提高其抗震性能。运用新型边坡加固抗震性能参数分析方法,采用基于极向条分的极限分析上限法和非线性Mohr-Coulomb破坏准则,分析边坡加固措施对边坡抗震性能的影响,通过对比有、无加固措施状态下不同能量功率的运算确定边坡抗震性能,利用MATLAB软件获取边坡加固抗震性能参数的最优解。经实验证明,边坡潜在破坏范围受边坡坡顶受荷和边坡加固情况的作用较大,地震荷载系数及非线性系数越大,土体强度非线性越小,边坡抗震性能受地震荷载的作用也越大。边坡抗滑桩最优抗震支护方位位于X_F/L_x=0.7处,在地震荷载从0上升至0.2的情况下,非线性系数为1.2、1.4、1.6以及2.0时的边坡抗震性能分别下降了40.1%、46.8%、57.5%以及61.5%。新型的抗震性能参数分析方法有效地提高了结果准确率,对边坡加固的抗震性能能达到准确分析。 相似文献
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《国际地震动态》2020,(7)
建筑结构地震反应观测是获取不同建筑结构在地震中的反应状态与特征的有效手段。河北省唐山古冶5.1级地震触发北京地区既有的建筑结构观测台阵,获得了丰富的建筑结构地震反应记录。开展台阵记录的初步分析,确定结构动力放大倍数和仪器烈度分布。分析发现,不同类型结构的动力放大倍数差异较大,钢结构较砌体结构的动力放大倍数更大。震中距较小的台阵的仪器烈度较大,最大达到2.5度。以第十九中学教学楼为例,开展单个观测台阵的地震记录分析,得到结构各楼层的水平向加速度分布,互功率谱分析得到结构振动的卓越频率。初步分析表明,基于观测记录数据分析能得到地震动特性和建筑结构动力特性参数,为了解区域建筑结构特性奠定有效数据基础。 相似文献
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《Advances in water resources》2005,28(7):701-710
The patterns of temporal variations of precipitation (P), streamflow (SF) and baseflow (BF) as well as their nitrate-nitrogen (nitrate) concentrations (C) and loads (L) from a long-term record (28 years) in the Raccoon River, Iowa, were analyzed using variogram and spectral analyses. The daily P is random but scaling may exist in the daily SF and BF with a possible break point in the scaling at about 18 days and 45 days, respectively. The nitrate concentrations and loads are shown to have a half-year cycle while daily P, SF, and BF have a one-year cycle. Furthermore, there may be a low-frequency cycle of 6–8 years in C. The power spectra of C and L in both SF and BF exhibit fractal 1/f scaling with two characteristic frequencies of half-year and one-year, and are fitted well with the spectrum of the gamma distribution. The nitrate input to SF and BF at the Raccoon watershed seems likely to be a white noise process superimposed on another process with a half-year and one-year cycle. 相似文献
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燕郊等测点迁移优化与地磁观测研究 总被引:1,自引:2,他引:1
为优化地磁观测条件,开展了燕郊、夏垫等测点迁移工作;按照测眯迁移原则与实施技术方案,完整地收集并整理了地质构造与地球物理等方面的基本资料;进行了野外实地勘察,磁场梯度的测量,确定了新测点,在新老测点上进行了较长时间的地磁场对比观测;应用多种方法分析研究了地磁对比观测资料,结果表明,新老测点与有关测点的地磁变化具有良好的一致性,并得到了新老测点之间的地磁数据的按点差。 相似文献
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We rederive and generalize hyperbolic moveout formulae for the common-midpoint (CMP) gather and for the zero-offset (ZO) section that can be efficiently used for macro-model-independent reflection imaging in two-dimensional media. The hyperbolic moveout formulae for the common-midpoint gather are obtained from different Taylor series expansions of a particular parametric moveout surface defined in the multicoverage data space. Such a moveout surface involves three kinematic wave-field attributes of two hypothetical waves, which have to be determined by a coherency analysis. By using hyperbolic moveout curves in the CMP gather and in the ZO section one can determine these attributes in two steps. The relationships between the local shapes of the interfaces and the attributes of the hypothetical wave-fields attributes are considered by means of geometrical optics. The determination of these attributes allows to perform a macro-model-independent ZO simulation and a subsequent inversion. 相似文献
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Vindell Hsu Charles E. Helsley Eduard Berg David A. Novelo-Casanova 《Pure and Applied Geophysics》1984,122(6):878-893
A close correlation in spatial distribution of local seismic activity and energy release patterns before and after the 1979 Petatlan, Mexico earthquake suggests heterogeneity within the fault plane of this major low-angle thrust event associated with subduction along the Middle America Trench. A simple two-asperity model is proposed to account for the complexity. Foreshocks and aftershocks of the neighboring 1981 Playa Azul earthquake showed a similar pattern. As both events occurred at the junction of the Orozco Fracture Zone and the Middle America Trench, we speculate that the observed complex fault plane is caused by subduction of the rugged ocean floor of the Orozco Fracture Zone. Short-term precursory seismicity prior to the Petatlan earthquake can be explained by using the asperity model and migration of a slip front from the south-east to the north-west across the main shock source region. 相似文献
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Summary This paper discusses the influence of system stiffness on the dynamic instability of fault surfaces under laboratory conditions for a number of test modes. In conjunction with shear load stiffness, the normal load stiffness, often neglected, is shown to have a considerable effect on the stick-slip process —its presence or absence and its characteristics. Also appropriate stiffnesses are suggested for an earthquake sequence modeled as a growing dislocation. 相似文献
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