Research status and prospects of Mathews stability graph method in mine stability assessment

Since its introduction in 1981, the Mathews stability graph method has become a key empirical tool for stability assessment in hard rock open stoping. This method addresses the challenges of deep, high-stress mining by modifying the NGI rock mass classification system. It incorporates a modified Q′ value along with three key adjustment factors—stress, joint orientation, and gravity—and combines them with the hydraulic radius to form the stability number N, ultimately creating an empirical stability chart. However, its direct application faces limitations in many Chinese mines due to prevalent fractured rock masses and complex in-situ stress conditions. To address this, research has focused on continuously expanding the database, refining the calculation models for each factor, and integrating probabilistic statistics and machine learning techniques. This has driven the evolution of the method from an empirical judgment tool towards a more quantitative and intelligent assessment system. Today, it has developed into a comprehensive analytical tool that integrates numerical modelling and engineering experience. Looking ahead, there is a need for localization and calibration to suit domestic geological conditions, developing a factor system applicable to fractured ore bodies and high-stress environments, and integrating it with dynamic monitoring technologies. Its core contribution to the industry lies in providing a stability assessment method with straightforward parameters, suitable for preliminary design. This has significantly enhanced the scientific rigor and reliability of stope design, offering a continuously optimizable analytical framework for the safe mining of deep and complex ore bodies.