Hebei Plain Ground Fissures And Earthquake Energy Release

The abroad appearances of the Hebei plain ground fissures have done harm to the subaerial buildings, the subterranean engineering of pipeline, the establishment of irrigation works and the cropland and road to a certain extent. There are 482 strips of the ground fissures in Hebei plain, which destroyed buildings and road and made the farmland leaking. The loss of economic reached 0.1 billion of yuan. Hebei plain is one of areas where the ground fissures are most active in China. Because they happened in denseness of population and in which where the earthquakes take place and develop with the ground fissures, they get the attention of geological field and the engineering and technology field.There are 212 places and 482 strips of ground fissures in Hebei plain ,They are amount to 176.2km. We find the extension of them is from south to north and from west to east. Their directions separately are SN, NNE, NE, EW and NW. Through the regionally tectonic research and fractal model, we can quantificationally deal with them. We find out the connectivity of them is bad, the domain is the regional light crack, and the inferior is the fault slow sliding.Through this study of the relation of the ground fissures and the earthquakes ,we can find out: the active climax of the ground fissures is later than that of the earthquake for 1—2 years. In the middle of this region and the near region, the earthquakes of the Xing'tai 7.2 Ms and Tang'shan 7.8 Ms are later than the ground fissures for 2 years in 1966~1976. With the recede of the intension and the frenquency of the 7th and 8th active scene, the active intension of the ground fissures is elevatory. The active climax of the ground fissures is later than that of the earthquake for 1 year.Through the study of the tectonic stress field causing the ground fissures and the earthquakes, we can analyse the mechanic mechanism of the ground fissures and the earthquakes.The tectonic stress field is the original force of the crust activity and metamorphose, so the study of tectonic stress field inspiring the ground fissures is the way that verifying the potentially dangerous region of the ground fissures. Utilizing the formerly actual data of Long'yao and Yi'xian, We can request the tectonic stress field through the finite element method of the plane. We can find out the relation of the ground fissures and the intension area of the stress. For example in He'jian , An'ping, Shen'ze stress intension occurs and He'jian is in the earthquake tectonic strip and the ground fissure of Shen'ze Zhongxiangli–Matuan—Anping Nanwangsong(5000m×0.16~1,10km×0.02~1.5). The good relation is in Rao'yang, Wuqiang, Shen'xian, Gao'beidian, Xin'ji, Laishui. It put forward the exploration analyse for the ground fissures.