The Characteristics of Grout Diffusion in Reduce Subsidence Mining with Abscission Layer Grouting

The roof abscission layer formed by coal mining changes dynamically with the mining of working face. The grouting of abscission layer is an important engineering method to reduce ground subsidence and protect ground buildings. By using empirical formula prediction, numerical simulation and tracer test, the dynamic development characteristics of abscission layer, storage space of grouting grout, diffusion law of grout and its influence on groundwater were studied. The results show that the separation space mainly exists in the top of water-conducting fracture zone, which develops and closes with the mining of working face. The grout is mainly stored in the horizontal abscission layer. Grouting grout diffuses with mining-induced fissures and groundwater flow. Under the dilution and purification of stratum and groundwater, the influence of grouting on groundwater quality is basically eliminated after 20 years.

Automated summary

This study investigates the dynamic development characteristics of the abscission layer and the impact of grouting on groundwater. The results indicate that the abscission layer primarily exists at the top of the water-conducting fracture zone and develops and closes with the mining of the working face. Grouting grout is mainly stored in the horizontal abscission layer and diffuses with mining-induced fissures and groundwater flow. The influence of grouting on groundwater quality is essentially eliminated after 20 years.