高速铁路地震预警时间与预警区域和震级的关系

The Relationship between Early Warning Time & Region of High Speed Railway and Earthquake Magnitude

为保证高速铁路的行车安全,根据地震动的区域衰减特点,通过构建的地壳速度结构,研究高速铁路在遭遇不同强度地震时可预警时间与可预警区域的关系。根据地壳速度结构、震中深度、震中距等给出可预警时间的计算方法;根据地震动峰值加速度衰减关系和设定的地震动阈值,确定地震发生后超过地震动阈值的可预警区域及其对应的可预警时间。研究结果表明:以震中为中心存在着1个来不及发布地震预警的预警盲区,而对于预警盲区之外的区域其可预警时间和可预警区域均随着震级的增加而增加,增加的幅度与可预警区域的地震动峰值加速度衰减特点和地壳速度结构密切相关;因此,在高速铁路地震预警系统的研发和布置中,必须考虑高速铁路具体线路所通过区域的地壳速度结构和地震动峰值加速度衰减特点。

To guarantee the safe operation of high speed railway,the relationship between early warning time and early warning region was studied for high speed railway under earthquakes with different intensity according to the regional attenuation characteristics of ground motion and the constructed crustal velocity structure.The calculation method for early warning time was proposed based on crustal velocity structure,the depth of epicenter,epicentral distance and so on.The early warning region higher than the threshold of ground motion after earthquake and its corresponding early warning time could be determined by combining Peak Ground Acceleration （PGA） attenuation relationship and the suggested ground motion threshold.The results indicate that there is a blind zone with no time for early warning in epicenter.While for the area beyond blind zone,both the early warning time and region will increase along with earthquake magnitude.The increasing extent is closely related to the PGA attenuation characteristics of early warning region and crustal velocity structure,which must be considered for the region across by the specific line of high speed railway in the development and layout of earthquake early warning system for high speed railway.