地震动破坏性与地震预警理论方法研究

发布时间：2019-05-16 18:09

【摘要】：本文针对地震防灾减灾领域的关键科学问题,开展关于地震紧急预警基础理论方法与地震动对结构破坏性的深入系统研究。具体研究内容如下:通过大量具有背景信息的强震记录,研究了基于短时记录的高精度P、S波的高效识别与拾取理论方法;针对震源参数和场地地震动参数预测问题,分别研究提出了具有预警意义的初始地震动特征参数,建立了典型预警特征参数与震源参数和场地地震动分布强度的相关性法则,提出了相应的地震预警理论与方法。同时研究了地震动参数与建筑结构损伤之间的直接因果关系,把握了未来地震对结构可能造成的破坏程度。通过研究,提出了高精度地震紧急预警的理论与方法,建立了地震动与结构破坏的相关关系,研究成果为开展快速准确的地震预警和早期灾害预测,构建更加合理的紧急预警与灾害评估相结合的地震应急系统提供了科学依据。主要工作内容及取得的成果归纳如下:(1)基于2008年汶川Ms8.0级地震的大量强震记录以及大区域的建筑结构倒塌率数据,研究推导了 20个灾害地区的建筑结构倒塌率CR与4个地震动参数(地面峰值加速度PGA、地面峰值速度PGV、最大加速度反应谱PSA、谱强度SI)之间的易损性关系,建立了相应的地震动对结构危害性判断准则;提出了一种合理有效评估结构损伤等级的理论方法,该方法能够有效排除不同地区不同抗震设计等级的影响。根据2008年汶川地震震后《建筑抗震设计规范》修订版规定的地震系数kR,计算得到了基于汶川地震地面峰值加速度PGA的建筑物预测倒塌率CRR值。结果显示,按照提高后的基本加速度指标设防,上述地区的建筑结构预测倒塌率均呈现显著降低。除八角、清平和卧龙地区分别减少到小于34%,54%和43%外,其他地区均减少到30%以下。(2)提出了一套适合于单台站地震预警的实时P、S波复合自动快速识别的理论与方法。首先通过提出的极化滤波方程对P、S波进行分离,进而引入调整系数δ对传统STA/LTA方法进行改进,并结合改良的基于高阶统计量的AIC算法推导P、S波的精确到时。应用具有代表性的地震记录对提出的方法进行有效性验证,通过汶川Ms8.0级地震的主震及其余震记录1398条,将自动拾取方法与人工目测拾取结果进行比较,P波与S波的拾取率分别达到91%和85%,拾取偏差分别为-0.021±0.068s;0.025±0.169s,结果显示提出的方法能够快速、有效地应用于具有复杂震源、传播路径以及场地条件下的地震预警,能够满足单台站地震预警过程中对实时性、准确性和高效性的严格要求。(3)研究提出了适合于单台站地震预警的快速准确确定地震震级的理论与方法。将提出的位移平方积分参数ID2的震级预测方法与具有代表性的既有预测方法进行比较分析。分别以平均周期参数τc与位移幅值参数Pd作为比较对象,应用汶川Ms8.0级地震的43个余震事件的加速度记录,建立了 3个特征参数与地震震级之间的相关关系,推导得到相应的地震震级预测公式。通过对比结果可知,提出的ID2方法对震级预测结果的可信度最高,较之其他既有方法具有明显优势。针对特征参数在预测大地震时普遍出现的震级"饱和"现象开展了研究。首先研究利用3s初始P波计算的特征参数在预测汶川Ms8.0级主震时的可能性,结果显示提出的位移平方积分参数ID2的预测震级更加准确。进而以ID2作为研究对象,通过研究调整时间窗长参数,提出的预测公式可以用于估计大地震的震级,基于6s初始P波的ID2方法能够达到预测8.0级地震的能力。(4)研究提出了适合于单台站地震预警的快速准确确定场地地震动的理论与方法。提出了基于3s初始P波的谱强度SI(3s)的地震动预测方法,利用汶川Ms8.0级地震的余震记录,研究比较了 3s谱强度SI(3s)、位移幅值Pd和速度平方积分IV2与地震动参数,即峰值加速度PGA、峰值速度PGV以及谱强度SI之间的相关性,建立了 3个特征参数与3个地震动参数之间的拟合关系,并推导得到相应的地震动预测公式。通过对比3种方法对地震动参数的预测结果,显示了提出的SI(3s)方法对预测地震动峰值加速度PGA的标准差最小,较其他既有方法具有更高的可信度,因此能够更好地应用于普遍采用的加速度参数预警模式。基于汶川地震主震与余震数据的解析与比较,提出了一种针对大地震后续地震动峰值进行预测的方法,通过引入修正系数对预警特征参数进行提前修正,可以缓解预测大级别地震时出现的地震动"低估现象",实现对大地震地震动持续过程的准确预测。(5)针对基于强震观测数据构建的地震预警理论与方法,通过地震动模拟理论开展了基于理论地震动的分析与验证。提出了通过地震数值模拟方法开展地震预警研究的理念与路线,这种方法具有良好的可行性与合理性,将为地震预警提供新的研究手段。运用三维地震动理论模拟方法,构建了典型三维震源模型和地下速度结构模型,开展了基于震源-传播路径-场地效应等全过程的宽频带地震动模拟计算,得到相应的理论地震动波形记录。针对提出的震级预警特征参数(位移平方积分ID2)以及地震动预警特征参数(3s初始P波的谱强度SI(3s),基于设定地震的240条理论地震波,建立了ID2与震级M的关系,以及SI(3s)与峰值加速度PGA、峰值速度PGV、谱强度SI这3个地震动参数的关系,从数值模拟的角度验证了提出的震级预测公式和3个地震动预测公式的有效性和适用性。
[Abstract]:In the light of the key scientific problems in the field of earthquake disaster prevention and reduction, this paper carries out an in-depth systematic study of the basic theory of earthquake emergency early warning and ground motion on the structure. The concrete research contents are as follows: the high-precision P and S-wave high-efficiency identification and pick-up theory method based on short-time recording is studied through a large number of strong-motion records with background information, and the problem of earthquake source parameter and ground motion parameter prediction is studied. In this paper, the initial vibration characteristic parameters with early warning significance are put forward, and the correlation law of the typical early-warning characteristic parameters and the seismic source parameter and the ground-ground motion distribution intensity is established, and the corresponding earthquake early-warning theory and method are put forward. At the same time, the direct causal relationship between the ground motion parameters and the structural damage of the building is studied, and the possible degree of damage to the structure of the future earthquake is grasped. Through the research, the theory and method of high-precision earthquake emergency early warning is put forward, and the relation between ground vibration and structural failure is established, and the research results are quick and accurate earthquake early warning and early disaster prediction. It provides the scientific basis for building a more rational emergency early-warning and disaster assessment. The main contents and achievements are summarized as follows: (1) Based on a large number of strong earthquake records of the Wenchuan Ms8.0 earthquake in 2008 and the collapse rate data of the construction structures in the large area, The vulnerability of the structure collapse rate CR and the four ground motion parameters (the ground peak acceleration PGA, the ground peak velocity PGV and the maximum acceleration response spectrum PSA and the spectral intensity SI) of the 20 disaster areas is derived. A reasonable and effective method for evaluating the level of structural damage is proposed, which can effectively eliminate the influence of different seismic design levels in different areas. According to the earthquake coefficient kR, which is specified in the earthquake-proof design code of the earthquake in 2008 and the revised edition of the earthquake-proof design code of the earthquake, the CRRs of the building predicted collapse rate based on the ground peak acceleration PGA of the Wenchuan earthquake are calculated. The results show that the predicted collapse rate of the building structure in the above-mentioned area is significantly reduced according to the improved basic acceleration index. In addition to the Octagonal, Qingping and Wolong areas, less than 34 per cent,54 per cent and 43 per cent, respectively, are reduced to less than 30 per cent. (2) A set of theory and method for real-time P and S-wave composite automatic fast recognition for single-station earthquake early warning is put forward. First, the P and S wave are separated by the proposed polarization filtering equation, and then the adjustment coefficient is introduced to improve the conventional STA/ LTA method, and the accuracy of P and S wave is derived in combination with the improved AIC algorithm based on higher order statistics. A representative seismic record is used to verify the effectiveness of the proposed method, and the automatic pick-up method is compared with the artificial visual pick-up result by the main shock and the aftershock record 1398 of the Wenchuan Ms8.0 earthquake. The pick-up rate of the P wave and the S wave is 91% and 85%, respectively. the pick-up deviation is-0.021-0.068 s; 0.025-0.169s, the result shows that the proposed method can be applied to the earthquake early-warning with complex source, propagation path and site condition, and can meet the real-time property in the single-station earthquake early-warning process, The strict requirements of accuracy and efficiency. (3) The theory and method of rapid and accurate determination of the earthquake magnitude suitable for single-station earthquake early warning are put forward. The magnitude prediction method of the proposed displacement square integral parameter ID2 is compared and analyzed with the representative existing prediction method. The correlation between the three characteristic parameters and the magnitude of the earthquake is set up by using the average cycle parameter and the displacement amplitude parameter Pd as the comparison object, and the correlation between the three characteristic parameters and the magnitude of the earthquake is established, and the corresponding earthquake magnitude prediction formula is derived. The result of comparison shows that the proposed ID2 method has the highest confidence in the prediction of the magnitude and has a distinct advantage over other existing methods. In this paper, a study of the magnitude "saturation" of the characteristic parameters in the prediction of large earthquakes is carried out. In this paper, the possibility of using the characteristic parameters of the initial P wave of 3s to predict the main shock of the Wenchuan Ms8.0 is first studied. The results show that the predicted magnitude of the proposed displacement square integral parameter ID2 is more accurate. Furthermore, by using ID2 as the research object, by studying the adjustment time window length parameter, the proposed prediction formula can be used to estimate the magnitude of the large earthquake, and the ID2 method based on the initial P wave of 6 s can reach the ability to predict the 8.0-level earthquake. (4) The theory and method of rapid and accurate ground motion for single-station earthquake early warning are put forward. A ground motion prediction method based on the spectrum intensity SI (3s) of the initial P wave of 3s is proposed, and the three-s spectral intensity SI (3s), the displacement amplitude Pd and the velocity square integral IV2 and the ground vibration parameters, i.e. the peak acceleration PGA, are compared and compared using the aftershock record of the Wenchuan Ms8.0 earthquake. The correlation between the peak velocity PGV and the spectral intensity SI is established, the fitting relation between the three characteristic parameters and the three ground motion parameters is established, and the corresponding ground motion prediction formula is derived. By comparing the prediction results of the three methods to the ground motion parameters, the proposed SI (3s) method is used to minimize the standard deviation of the predicted ground vibration peak acceleration PGA, and the other existing methods have higher reliability, so that the early warning mode of the acceleration parameter commonly adopted can be better applied. Based on the analysis and comparison of the main earthquake and the aftershock data of the Wenchuan earthquake, a method for predicting the subsequent ground motion peak of a large earthquake is proposed, the early correction of the early-warning characteristic parameters is carried out by introducing the correction coefficient, and the ground shock "understate" in the earthquake of the large-scale earthquake can be reduced, And the accurate prediction of the continuous process of the large-scale earthquake ground motion is realized. (5) Based on the theory and method of the earthquake early warning based on the strong earthquake observation data, the theoretical ground motion analysis and verification is carried out by the ground motion simulation theory. The concept and route of earthquake early warning research by means of seismic numerical simulation are put forward. The method has good feasibility and rationality, and will provide new research means for earthquake early warning. A typical three-dimensional seismic source model and the underground velocity structure model are constructed by using the three-dimensional seismic theory simulation method, and a wide-band ground motion simulation is carried out based on the whole process of the source-propagation path-field effect and the like to obtain the corresponding theoretical ground vibration waveform record. The relationship between ID2 and magnitude M, and SI (3s) and peak acceleration PGA and peak velocity PGV are established for the proposed earthquake magnitude early-warning characteristic parameters (displacement square integral ID2) and the ground motion early-warning characteristic parameters (3s initial P-wave spectrum intensity SI (3s). The relationship between the three ground motion parameters of the spectrum intensity SI is verified, and the validity and the applicability of the proposed magnitude prediction formula and the three ground motion prediction formulas are verified from the angle of the numerical simulation.
【学位授予单位】：北京交通大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：P315

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