This paper briefly introduces software design of the Earthquake case Database of china and Its Application System which was implemented on VAX 780 with DBMS and passed through specialistic appraisal in December 1991.

Dynamic strength fracture of reticular shells under severe earthquakes;

With a finite element software ANSYS, the dynamic response of reticular shells under severe earthquake excitation was investigated, in which geometric non-linearity and material non-linearity were all taken into account.

At tresent,there is no seismic design code for long span and high pier continuing girder bridges,especially under severe earthquake.

Probability assessment of land use suitability with ground surface ruptures induced by strong earthquakes;

Research on control measures of transverse joint deformation of the Xiaowan Arch Dam under the action of strong earthquakes;

Response of transportation tunnels due to strong earthquake;

Study on the relation of solar activity and strong earthquakes occurred in North China;

Based on the study of Akio Yoshida etc,taking North China(30°～42°N,109°～125°E)as the sample area to study the relationship between the space-time distributions of moderate and strong earthquakes in Chinese mainland.

Strong earthquakes correlate closely with lunar phases in North China and its seismic belts.