The earth pressure curve and bending moment curve on lining versus the prop time are presented . the anchor reinforce effect in various rocks is analyzed and the reasonable support time for cracked surrounding rocks is put forward 并对支护时机与衬砌上压力、弯矩的相互关系、不同岩体锚杆的加固效果进行了分析研究，提出了破碎围岩的合理支护时机。
