DEVELOPMENT FEATURES OF GROUND FISSURE IN SHUANGHUAISHU VILLAGE,SANYUAN COUNTY,SHAANXI PROVINCE

Huge hazards and economic losses are caused by the ground fissure in Shuanghuaishu Village,Sanyuan County,Shaanxi Province.The ground fissure is consist of two paralleled fissures over 4 km length.Some works of exploratory trench,exploratory well and tunnel are done on site of the fissures.Then the features of plane distribution,section structure,activity and mechanics of the fissures are described in the paper.The exploratory results reveal that the F1 fissure on the south side of Shuanghuaishu ground fissure has larger width of fracture zone and higher active level than the F2 fissure on the North side.There are over 50 m wide areas and over 30 cracks in the fracture zone of the F1 fissure,which is not common in the loess area.