不同震动参数对反复微小地震下边坡动力响应规律的影响

利用ABAQUS软件建立了坡度为30°和60°的三维边坡动力数值分析模型,选取地震波类型、幅值、频率、震次和坡度等影响指标,对反复微小地震下边坡动力响应规律进行了分析。结果表明:“先强后弱”类型的地震波引起的边坡响应要强于“先弱后强”类型的地震波,正弦波作用时引起的边坡响应要远小于天然地震波;坡面加速度峰值放大系数随着震次的增加而减小,且陡坡的减弱趋势要大于缓坡的减弱趋势,地震波幅值越大引起的坡面水平加速度越大。研究结果有助于认识近年来反复微小地震中各类因素对于边坡动力稳定性的影响。

Forward Modeling of the Relationship Between Reflection Coefficient and Incident Angle of the P Wave in a Coal Seam

Although the Zoeppritz equation is suitable for a single interface in a thick deposit, it has some limitations for composite reflection waves from both the floor and the roof of coal seams. Based on the ray model, the relationship of the overall reflection coefficient of composite reflection P waves, from coal seam versus incidence angle (AVO), is dis- cussed. The result shows that: 1) the overall reflection coefficient of composite reflection waves from coal seams is a negative value and is determined mainly by the lithology of roof and floor, which is different from the reflection coeffi- cient of a single interface; 2) if the incidence angle ranges from 0° to 6°, the reflection coefficient of composite waves of a coal seam does not change with the incidence angle and 3) if the incidence angle ranges from 6–60° , the reflection coefficient increases monotonically.

Slip rate along the Lijiang-Ninglang fault zone estimated from repeating microearthquakes

Seismicity 并且沿着在 1999 和 2006 之间的 Lijiang-Ninglang 差错地区滑动率被调查，波形数据由云南数字地震网络记录了。由双差别方法的重定位的 seismicity 清楚地展出在北、南部的片断之间的不同特征。超过 76% 地震在丽江区域附近发生在差错的南部的片断。重定位的 seismicity 看起来反映学习区域的外壳的速度结构。用跨关联的分析，我们识别了显示出高波形类似的 92 件马甲和 70 根多重谱线的一个总数。大多数这些序列是非周期的，复发间隔从一些分钟变化到几百天。用在学习时期上定期发生了的二个序列，我们获得了一个差错在 ∼23 km 滑动约 5 mm/a 的率，在对的好同意地质并且表面 GPS 测量。