Stope structure evaluation based on the damage model driven by microseismic data and Mathews stability diagram method in Xiadian Gold Mine

Abstract

To obtain a better economic benefit, Xiadian Gold Mine intended to increase the stope structure parameter from 2.5 m (height) to 8 m. A test stope using the new structure parameter was mined to verify the surrounding rock’s stability. Based on the mechanical indices relating to the ore and rock, the “static” stability of the test stope under the new stope structure was analyzed by the Mathews stability diagram method. Then, a microseismic (MS) monitoring system was installed around the test stope to determine the “dynamic” stability of the test stope during mining. The spatio-temporal evolution of MS events was analyzed to understand the failure behaviors of the surrounding rock. Based on the MS monitoring results, a damage model was established and used to quantify the damage degree and dimension within the surrounding rock during mining the test stope. The study results show that the damage degree increased from less than 0.05 to 0.6, the damage dimension increased from less than 1500 m2 to more than 14,000 m2, and the shear plastic zone appeared around the two sidewalls and the roof of the stope. The results show that the test stope is at risk of instability under the new stope structure.

Keywords

• microseismic monitoring
• numerical simulation
• damage evolution
• mathews stability diagram