New Type of Similar Material for Simulating the Processes of Water Inrush from Roof Bed Separation.

With an increase in the mining depth and breadth of coal mines in China, water inrush accidents from the roof bed separation of a mining face have become more frequent. A similar simulation experiment in the laboratory is an important way to study the dynamic seepage processes of separation water and explore the mechanism of roof bed separation formation. In this study, we develop a new type of similar material to simulate strata separation. The skeleton of this material is made from river sand, while nanosized calcium carbonate, Ca-bentonite, gypsum, and emulsified wax act as additives. These synthetic materials are then used for the compressive strength experiment, the water permeation height experiment, the structural stability experiment, and the microscopic analysis. Besides, a physical experiment is also conducted to verify the effectiveness of this new similar material. This work could provide the scientific basis for the prediction and control of water accidents caused by the separation strata.