Study on tectonic stress field in Yingjiang area based on multi-focal mechanism solution sequence

In this paper, a total of 162 focal mechanism solutions are collected from several focal mechanism solution sequences in Yingjiang area, and the tectonic stress field inversion is carried out from Sudian fault to Dayingjiang fault. The results show that the axial direction of the total principal compressive stress in this area is NNE—SSW. The six earthquake swarm activities from March 21, 2008 to May 30, 2014 were analyzed from the perspective of internal dynamic evolution, and it was found that there were obvious interrelationships among them. It is also found that the deflection of stress field occurs locally. The deflection angle of principal compressive stress axis at the southern end of Sudian fault becomes larger, which may be related to the triangular depression formed in this area. In addition, 1003 earthquake catalogues occurred in Yingjiang area from 2016 to 2020 were collected in this paper. Through analysis, it is found that there is stress locking in the area between Xima-Panlongshan fault and Dayingjiang fault, so it is very important to strengthen the risk prevention in this area.