Excavation damage affects the stability of underground structures, making strong support systems essential. This study looks at how excavation damage zones influence the design of these support systems. Using a mix of computer modeling, borehole inspections, and lab tests, we examine how these damaged areas impact strength of surrounding rock mass and support effectiveness. Traditional methods often assume a uniform disturbance throughout the rock, leading to overly cautious results that don’t match real conditions. To improve accuracy, we created models with different disturbance levels for various rock zones. The strength reduction factor of roof improved from 1.01 to 1.78 when varying disturbance factors were assigned to different zones, compared to a uniform factor of 0.7 across the rock mass. Our findings show the importance of accurately identifying excavation damage zones for designing better support systems. This research helps us understand excavation damage better and offers ways to improve support system design, ensuring safer and more stable mining operations.