STUDY ON MODIFICATION OF GEOSTRESS AND FORECAST OF ROCKBURST BASED ON DESTRUCTIVE SIZE OF ROCKBURST

Combining the actual rockburst status after excavation,based on the previous research data in the earlier stage,the character of the tectonic stress in Cangling Tunnel is studied.Finite element method is adopted to simulate the site excavation steps.At the same time,the tectonic stress is changed on the boundary of the model to simulate the actual rockburst areas;and the most proximal area′s value is adopted to decide the section tectonic stress.Then,other sections′ values are revised.After comparing the theoretical values with the site measured values,it is concluded that the revised tectonic stress is coincident with the basic rule.It is also presented that the calculating status is parallel with rockburst areas in undisturbed area.It comes to an end that the method to forecast rockburst is feasible and reasonable.