Abstract: Based on the fact that the aquifer and goaf underwater coal seam for deep mining can be influenced easily by flood, it takes the geological conditions of the 29# first coal mining face under the ponding of Jixi Xinfa coal mine goaf as the background. According to the key strata theory, roof migration law, fracture development characteristics in the stope and other theories, the similar material stimulation experiment is adopted to study the development height of the roof fracture zone of the working face, the distribution of stress variation and its distribution law. The rational similar material ratio can be determined on the basis of the physical parameters of the coring rocks on the site which have been measured by experiments, thus further constructing the similar experiment model to stimulate backstopping, the results of which indicate the height of the crack belt is 21.8m, the height of the caving zone is 4.5m and the maximum stress peak of the main roof is 30KPa. In contrast to the testing data of face drilling, the measured height of the crack belt by drilling is 23.1m and the height of the caving zone is 4m. Therefore, the experimental data is -1.3m and 0.5m different from the measured data, and the maximum difference is smaller than 9%, which is in line with the requirements of error standard. Thus, the reliability of studying water-flowing fractured zone by similar stimulation can be verified, and the development of 29# coal water-flowing fractured zone in Jixi mine lot can be revealed.

Key words: similar simulation, goaf hydrops, height of crack belt