高地应力下隧道围岩动力损伤分析  

Study of dynamic damage of surrounding rocks for tunnels under high in-situ stress

作　　者：杨栋[1] 李海波[1] 夏祥[1] 罗超文[1] 李卫兵 

机构地区：[1]中国科学院武汉岩土力学研究所岩土力学与工程国家重点试验室,武汉430071 [2]中铁十六局集团第五工程有限公司,河北唐山063030

出　　处：《岩土力学》2013年第S2期311-317,共7页Rock and Soil Mechanics

基　　金：国家自然科学基金资助(No.50809070);国家973计划项目资助(No.2010CB732001)

摘　　要：为预估和控制爆破荷载作用下围岩损伤范围,在赣龙铁路梅花山隧道工程现场进行岩体声波测试,得到围岩的损伤范围。根据爆破荷载作用下岩体损伤发展规律,采用基于概率形式的损伤变量定义,运用三维有限差分软件对不同地应力状态下爆破产生的围岩损伤范围进行数值模拟,并与现场岩体声波测试结果进行比较。计算结果表明,数值计算与实测结果有较好的一致性,随着地应力大小增大,围岩损伤范围呈现先减小后增大的趋势,且增大幅度较大,地应力较高时,局部部位如顶板、底板损伤更为明显,说明地应力大小对围岩损伤分布有着显著影响;随着侧压力系数增大,损伤范围先减小后增大,但增速逐渐减小。所得到的结论可为高地应力下隧道稳定性分析和支护设计提供依据。In order to forecast and control the damage zone of surrounding rock under blasting load, sound wave tests have been conducted in the construction site of Meihuashan Tunnel in Jiangxi province dragon railway. Based on the change rate of sound wave speed, damage zone size of surrounding rock are obtained. On this basis, a statistics-based damage variable of rockmass has been proposed based on micromechanics. Damage zone size of surrounding rock under blasting load at different in-situ stresses is thus studied by using three-dimensional finite difference software. Calculations show that the numerical simulation results agree well with the site monitoring results. With the in-situ stress increasing, the size of damage zone decreases first, then increases, and increases by a large margin;when the in-situ stress is high, local parts such as tunnel roof, floor damage is more obvious; it is shown that the in-situ stress has significant impact on surrounding rock damage distribution. With the lateral pressure coefficient increasing, the size of damage zone decreases first, then increases, but the growth rate decreases. The results provide foundation for stability analysis of tunnels under high in-situ stress and supporting design of the cracked surrounding rock.

关 键 词：岩石力学 围岩损伤 爆破 高地应力 

分 类 号：U451.2[建筑科学—桥梁与隧道工程]