2017年8月8日九寨沟7.0级地震长波辐射异常特征

通过距平方法，研究2017年8月8日九寨沟7.0级地震前震中所在区域（95.00°—110.00°E，25.00°—45.00°N）长波辐射时空演化特征，研究结果表明:①2017年7月，去除背景之后的长波辐射场在震区附近出现显著增强现象，增强区域基本走向与地质构造走向一致，其主体区域沿着巴颜喀拉块体南缘边界带，重要分支横跨巴颜喀拉块体，直接延伸至九寨沟7.0级地震震中；②紧邻九寨沟7.0级地震震中的4个格点在去除背景变化后的长波辐射时序曲线变化特征基本一致，即在2017年7月出现显著大于其他月份的现象。

Anomaly of Outgoing Long-wave Radiation before the M7.0 Jiuzhaigou Earthquake on August 8, 2017

In order to quantify the deformation performance and failure characteristics of RC columns under earthquake action, this paper collected 123 reinforced concrete (RC) column test data from PEER (Pacific Earthquake Research Center) database, and proposed the standard of RC column failure morphology based on parameter shear span ratio and bending-shear ratio. Under the three failure modes of bending failure, bending shear failure and shear failure, the significant effects of parameters such as axial compression ratio, shear span ratio, hoop characteristic value, volume hoop ratio, longitudinal reinforcement ratio on the displacement angle were studied. Through regression analysis, the regression equations of yield displacement angle and ultimate displacement angle under three failure modes were summarized and the significance probability of regression coefficient is less than 0.05. The results show that the criterion of RC column damage morphology proposed in this paper has high accuracy and strong adaptability; the linear regression equation of displacement angle is reasonable.