【作者】 马强；

【导师】 金星；

【作者基本信息】 中国地震局工程力学研究所 ， 防灾减灾工程及防护工程， 2002， 硕士

【摘要】 在地震预报这个世界性的科学难题在短期内很难得到突破性的进展而地震又在不断的造成巨大的经济损失和人员伤亡的背景下，基于实时强震观测台网、具有智能应急控制功能的各种重大工程与城市的地震预警系统日益引起政府和人们的广泛关注。本文对国内外地震预警系统的研究现状做了总结，在此基础上，对地震动参数实时处理技术进行了研究，其主要工作如下： 1．本文简要归纳了地震预警的基本思想及国内外研究现状后，讨论了地震预警中要解决的关键科学及技术问题，指出地震动参数的实时处理技术是实现地震预警的基础。 2．对强震观测数据的实时处理技术进行了研究。本文在Kanamori等人研究工作的基础上，发展了一套强震观测数据的实时处理技术，分析了递归滤波器设计参数q与所对应的低频截止频率f_c以及相位校正的定量关系。利用此套技术可对实时传输的加速度记录同步进行长周期基线校正、积分求速度及积分求位移。这为大批量、快速处理强震记录奠定了基础。 3．基于地震动参数如反应谱及Wood-Anderson地震图的计算可归结为单自由度系统的地震反应分析这一基本思想，本文分析了计算单自由度系统地震动力反应的单边差分方法。从递归公式传递函数与理论传递函数比较的角度研究了计算中的精度及所存在的问题。单边差分方法在计算单自由度系统地震动力反应中引入了较大的人为阻尼，随着采样间隔及自振频率的增大而不能生成窄频带反应，系统的相位也会发生较大的畸变。为了生成窄频带反应，本文根据Kanamori等人的方法调整了计算时的阻尼比及自振周期，调整后的单边差分方法能在共振区域生成很好的窄频带反应，但是对一些周期点的阻尼比调整成为了负值，这从系统的动力平衡方程是难以解释的。调整后的单边差分方法在有效的计算频带内仍然不能较好的模拟理论传递函数尤其是相位特征，这说明Kanamori等人的方法并不是一个很好的方法。 4．为了搞清目前常用单自由度系统地震动力反应时域算法的精度及所存在的问题，本文比较了四种常用算法，即中心差分方法、Newmark方法、Z变换方法及Duhamel逐步积分法。本文把四种方法统一写成递归格式，从理论上研究其共性特征，然后从递归公式所构造的数字滤波器的传递函数与理论传递函数比较的角度进行了分析。分析中可以发现，中心差分方法，Newmark中点加速度方法、Z变换方法及Duhamel逐步积分法在精度范围内其计算相位是没有畸变的， 中国地震局工程力学研究所顷土学位论文一但是中心差分方法，Newmark中点加速度方法随着采样间隔及系统自振频率的增大，系统的固有自振周期被改变，其传递函数的共振区域与理论传递函数的共振区域会发生分离。Z变换方法及Duhaln逐步积分法的精度较高，但是在一定的有效频带范围内仍有较大的误差。本文证明了递归系数b；和 b。与传递函数极点的理论关系，得到了传递函数低频约束条件和传递函数相位不发生畸变的补充条件。通过动力方程的不变性说明了相对位移、相对速度和相对加速度三个递归公式的内在关系。在此基础上推荐了一套计算单自由度系统地震动力反应递归公式。 5．本文通过理论分析，找到了一种在计算精度上与频域方法相当的时域递归方法。本文对所推荐的计算单自由度系统地M眨动力反应的递归公式进行了系统分析。由于这套公式只有一个待定参数6，通过动力平衡方程本文得到了5的理论公式，并与用谱比方法通过最小二乘法得到的6进行了对比分析，数值分析表明谱比方法得到的sng好些，进而得到了5的统计关系式。通过大量的计算表明该方法的计算精度优于比较研究过的其他时域算法。利用本文方法可实现对地震动参数如反应谱和WodAntw地震图的实时计算。 最后，作者对本文的研究工作进行了总结，讨论了今后应该进行的研究工作。更多还原

【Abstract】 In a short time, as we know, it is very difficult to acquire great advances in research field of predicting earthquake, however, major earthquake frequently occurs in the world and cause a great deal of economic losses and people’s death. Therefore, it is easy to understand that government and society especially pay attention to seismic early warning system which is considered as affective measure of mitigating disaster caused by earthquake. In this paper, the research advances of earthquake early warning system is briefly summarized and the real-time processing technique of strong ground motion parameters is mainly researchedThe main achievements of this study could be summarized as follows:1. Trie concept of seismic early warning system (EWS) is discussed and the research advances is briefly summarized in this paper. Based on this, the practical scientific and technological problems of EWS are discussed. As the base of EWS, the rail-time processing technique of strong ground motion parameters is pointed out.2. The real-time processing technique of strong ground motion data is studied in this paper. Based on the research of Kanamori etc., the relation between the design parameters of recursive filter and its corresponding Low frequency cut-off frequency is obtained and quantitative phase adjustment is analyzed. By using this technique, the baseline of transmitting acceleration data in real time is adjusted, and the velocity and the displacement are integrated synchronistically. Based on this technique, a batch of data can be processed quickly.3. The calculation of response spectrum and Wood-Anderson seismogram can be considered as the response of single-degree-of-freedom (SDOF) system to ground motion. From the viewpoint of this, the forward difference method for calculating the SDOF system is analyzed in this paper. The accuracy and the existent problem of forward difference method are analyzed on the basis of comparing the transfer function of recursive formula with theoretical transfer function. The factitious damping is introduced in the forward method, and with the increasing of time interval and natural frequency, the method completely fails to reproduce the narrow-band response. Furthermore, the phase of system is changed greatly. To reproduce the narrow-band response, based on the thought of Kanamori etc., the damping ratio and natural period are modified. Through this adjustment, thenarrow-band response can be reproduced, but for some natural periods the adjustive damping ratio has become negative. The negative damping is strange and can not be explained by the equation of motion for SDOF system. Furthermore, in effective frequency-band, the transfer function can not accurately simulate the theoretical transfer function, especially for phase property. It shows that Kanamori’s method is not a good one.4. In order to make it clear that the accuracy and the existent problem of typical algorithms of time-domain method, four numerical step-by-step methods are reviewed and compared in this paper. Based on the unified recursive formula, the four algorithms included in this study are the Central Difference Method, the Newrnark’s method, Z-transform method, and Duhamel’s step integral method. The accuracy, the phase and other existent problem are studied in this paper. It is proved in this paper that the recursive parameters b1and b2are relate to the poles of theoretical transfer function. Furthermore, the constraint condition of the transfer function at the zero frequency and the phase invariability condition of transfer function are presented. Based on the invariability of dynamic equation, the interrelation among recursive equation of relative displacement, velocity and acceleration are also obtained. At last, an algorithm for calculating response of SDOF system to ground motion is suggested.5. According to the analysis mentioned above, a set of recursive formula is found whose precision is equivalent to that of frequency-domain method. Only one undetermined parameter 8更多还原