MODEL TEST FOR EVOLUTION OF GROUND FISSURES DUE TO EXTRACTION OF GROUNDWATER

In order to study the formation mechanism of ground fissures in southern Jiangsu, a large-scale physical model is established under the buried-hill condition. The settlement process with water-drawing variability can also be simulated. Fiber optic sensing technology is used for revealing the development and evolution of ground fissures. The distribution and the genetic evolution of ground fissures are summarized. The test results are below:(1)The results of model test are basically consistent with the law of ground fissure disaster in the study area, which provides new methods and means for ground fissure research. (2)The tensile stress concentration of the rock mass is basically the same as the development stage of the ground fissure. Therefore, the stress concentration of the rock mass is an important omen to determine the development stage of the ground fissure. (3)According to rose diagrams analysis, in the flat region, ground fissures are radially distributed and its distribution center is near the drain holes. At the buried hill area, it shows that the shape and location of the buried hill, the settlement curve, and the most serious land area are consistent with the distribution area of ground fissures. (4)Excessive groundwater extraction as well as the location of buried-hill formation have a great influence on the distribution of ground fissures.