The Analysis Of Report About Earthquake Risk In Huludao City And Circumference Region

Seismic fatalness is estimated in Huludao and the surrounding area in terms of tectonic specialities, seismic activities in history and earthquakes temporal and spatial distributions.(1) In this paper, seismic fatalness is estimated by using data with different accuracies. As the accuracies at different periods change, and the accuracies are different at different seismic nets, the method in this paper can be properly used by data of different periods. It's not necessary to get historical data at each period, and it's not necessary to select the greatest earthquake with the same interval. Furthmore, the method can be used even though there are gaps between historical data and present data, and the accuracies are different at different periods.(2) The latent focal area is determined by the tectonic analogy method and the principle that historical earthquakes can replay. That's to say, at a certain magnitude, every position of the focal area has the same earthquake happening possibility, satisfies the G ? R relation, and comply with the Possion model.(3) The seismic influence attenuation relation is decided by using the method which is similar to definite and probable method.(4) The fatalness of sites is got. On the basis of the assumption that one earthquake time complies with Possion model, the probility of ground motion in a certain period can be got by summing up all the probilities of latent focal areas and influences on sites from different earthquakes.(5) On the basis of seismic fatalness probility method and basical parameters, the following parameters are calculater: seismic intensities at two sites in Huludao(intensity attenuation formular and elliptical attenuation model are used), peak value of rock acceleration and peak value of reflection spectrum (elliptical attenuation model and the attenuation relation between peak value of acceleration and reflection spectrum are used).(6) The result from sites reflection analysis shows that the acceleration peak value is vey high in the west of Liulihe Road, the acceleration peak values are very low in three areas: in the Shuangtaizi district, between Changzheng Street and Shengli Street, in the west of Niuguantun, and the acceleration peak values in the other areas are moderate. Characteristic period Tg is reverse to acceleration peak value. For example, the area with high acceleration peak value has low Tg, which shows that soft earth layer has high acceleration peak value but low Tg. In terms of caculation results and earth layer distributions inHuludao, ground motion plotting can be got in districts, and ground motion parameters are provided for each district...