中文摘要：

考虑拉、压弹性模量不等以及水平应力作用，引入Norton非线性应力应变关系及Kachanov损伤演化规律，建立了采空区顶板的蠕变损伤模型。定义弹性模量比例系数d及水平应力系数缸表征弹性模量和轴向压力对蠕变损伤的影响，给定特定参数分析了断裂孕育时间、有效应力、有效高度、损伤因子等随a，kx和材料参数m的变化规律。结果表明：随着a的增大，顶板中的拉应力降低，断裂孕育阶段延长，断裂前缘扩展速率减慢，并且拉应力区高度减小；水平应力减少了顶板横截面上的最大拉应力，延缓了顶板的宏观开裂时间，使顶板的破坏区变小，岩体拉压弹性模量的差异及硐室水平应力的作用对顶板的损伤特性影响很大，不可忽略。所得结论为有效抑制顶板岩梁的裂纹扩展，维护巷道顶板稳定提供了理论依据。

英文摘要：

Considering the different modulus in tension and compression and action of horizontal stress-field, creep damage model of roof of soft rock tunnel was established based on Norton nonlinear law and Kachanov＇s damage evolution law. The effects of modulus difference and horizontal stress-field on the damage characteristics of tunnel roof were involved by definitions of modulus coefficient and horizontal stress coefficient kx. The changes of damage incubation time, effective stress, effective height and damage factor with u, kx and material parameter m were analyzed by given parameters. The results show that the height of tensile stress area and propagation rate of fracture front of tunnel roof decrease with the increasing of a. On the contrary, macroscopic cracking time is prolonged. Failure area of roof became smaller because of the decreasing of tensile stress under the effect of horizontal stress. Therefore, modulus difference and horizontal stress-field exert a great influence on damage characteristics of tunnel roof and cannot be ignored. The conclusions provide a theoretical basis for effectively inhibiting the crack propagation and maintaining stability of tunnel roof.