Characteristics of long period microtremor and validation of microtremor array measurements in inlan

来源 :Journal of Mountain Science | 被引量 : 0次 | 上传用户:zhxg
下载到本地 , 更方便阅读
声明 : 本文档内容版权归属内容提供方 , 如果您对本文有版权争议 , 可与客服联系进行内容授权或下架
论文部分内容阅读
To study the characteristics of long period microtremor and applicability of microtremor survey,we have made microtremor observations using long period seismometers of the China’s mainland from coastal cities like Shanghai and Tianjin through Beijing,Xi’an,to the far inland cities of Lanzhou and Tianshui.The observation shows that the level of power spectrum of long period microtremors reduced rapidly from the coast to the inland area.However,the energy of long period microtremors in Beijing,Xi’an,Lanzhou and Tianshui area are only approximately ten-thousandth to thousandth of that in Shanghai.Aiming at the complexity of the underground structure in the far inland,a series of underground structure models with different distributions were assessed using three-dimensional,dynamic finite element method(FEM) analyses.The results were used to evaluate microtremor survey methods and their limitations with regard to aggregate variability and thickness determinations.Multiple-wave reflections between layers with the change of underground structure distribution occurred,which have significant effect on the performance of the different field approaches.Information over a broad spectrum from which velocity-depth profiles were produced via inversion approaches.Neither the thickness nor the shear waveVelocity V of the subsurface layer inversion results appeared over a large evaluation with increasing slope angle.In particular,when the angle of the model reached 45°,it could not be accurately evaluated using one-dimensional inversion methods.Finally,the array microtremor survey(AMS) was carried out in Shanghai City,China.Although AMS techniques do not have the layer sensitivity or accuracy(velocity and layer thickness) of borehole techniques,the obtained shear wave velocity structure is especially useful for earthquake disaster prevention and seismic analysis. To study the characteristics of long period microtremor and applicability of microtremor survey, we have made microtremor observations using long period seismometers of the China’s mainland from coastal cities like Shanghai and Tianjin through Beijing, Xi’an, to the far inland cities of Lanzhou and Tianshui The observation shows that the level of power spectrum of long period microtremors reduced rapidly from the coast to the inland area. However, the energy of long period microtremors in Beijing, Xi’an, Lanzhou and Tianshui area are only approximately ten-thousandth to thousandth of that in Shanghai. Aiming at the complexity of the underground structure in the far inland, a series of underground structure models with different distributions were assessed using three-dimensional, dynamic finite element method (FEM) analyzes. The results were used to evaluate microtremor survey methods and their limitations with regard to aggregate variability and thickness determinations. Multiple-wave reflections between layers with the change of underground structure distribution occurred, which have significant effect on the performance of the different field approaches. information over a broad spectrum from which velocity-depth profiles were produced via inversion approaches. Neither the thickness nor the shear wave Velocity V of the subsurface layer inversion result has been over a large evaluation with increasing slope angle. In particular, when the angle of the model reached 45 °, it could not be as accurately evaluated using one-dimensional inversion methods. Finally, the array microtremor survey (AMS) was carried out in Shanghai City, China. Although AMS techniques do not have the layer sensitivity or accuracy (velocity and layer thickness) of borehole techniques, the obtained shear wave velocity structure is particularly useful for earthquake disaster prevention and seismic analysis.
其他文献
在我国教育改革的大环境之下,幼儿教育受重视程度越来越高,在教育模式上也做出了适当的改变.采用游戏化的教学模式比较符合孩子的天性,能在最大程度上吸引孩子的注意力.因此
期刊
  目的 评价穿支皮瓣修复手部中小面积皮肤缺损的疗效及安全性。方法 应用不同部位穿支皮瓣游离移植修复手部中小面积皮肤缺损。其中手部大鱼际桡动脉掌浅支穿支皮瓣10例,前
会议
如何有效开展小学道德与法治课堂活动是道德与法治课研究的重点课题.提出了提升小学道德与法治课堂教学有效性的策略,希望可以对小学道德与法治课堂教学活动的开展提供一定的
  目的 探讨应用足背穿支皮瓣修复足远端大面积皮肤软组织缺损的临床疗效.方法 8例足远端皮肤软组织缺损并骨外露创面,应用足背动脉远端穿支皮瓣修复治疗.其中切取单纯以足
会议
  目的 评价急诊足趾移植拇、手指再造的疗效及安全性。方法 急诊应用足趾或携带足背皮瓣移植再造拇、手指。其中拇甲瓣移植再造拇指8例(携带足背皮瓣2例),第2足趾移植再造
会议
劳动是一个人的基本素质,帮助培养幼儿良好的劳动习惯,从长远来看,幼儿能够受益终身.但现阶段在幼儿劳动教育中,存在很多共性问题,如家长主动干涉幼儿劳动、幼儿性格娇惯不愿
期刊
英语阅读是学生信息输入的重要方式,对学生的英语学习有着很大的帮助.但就农村小学生的英语阅读能力发展而言,其英语阅读能力处于较低水平,不满足于英语阅读学习的需要.为改
  目的 探讨应用胫后动脉内踝上穿支皮瓣修复踝足部皮肤软组织缺损的临床疗效.方法 10例踝足部皮肤软组织缺损并骨、肌腱外露创面,应用胫后动脉内踝上穿支皮瓣修复治疗.其
会议