大断面小净距隧道原位扩建爆破振动控制  

Blasting Vibration Control of Local Expansion of Large Section Tunnel with Small Cycle Distance

作　　者：李秀地[1,2] 蒋树屏[3] 刘元雪[1,2] 黄伦海[3] 胡英国[1] 

机构地区：[1]后勤工程学院土木工程系,重庆401311 [2]后勤工程学院岩土力学与地质环境保护重庆市重点实验室,重庆401311 [3]招商局重庆交通科研设计院有限公司,重庆400067

出　　处：《爆破》2014年第3期85-90,共6页Blasting

基　　金：国家自然科学基金项目(51378496);福建省交通科技发展项目(200910)

摘　　要：为控制原位扩建隧道爆破开挖对邻近运营隧道结构安全的影响,以国内罕见的大帽山大断面小净距隧道原位扩建施工为背景,从炸药直接起爆的角度,利用ANSYS/LS-DYNA软件建立了邻近运营隧道情况下隧道原位扩建爆破效应的数值计算模型,分析了爆破应力波在围岩和运营隧道衬砌中的传播规律。数值分析表明:围岩破坏应变的大小对计算结果影响较大,通过数值模拟与爆腔尺寸经验公式计算结果的比较得到了围岩的合理破坏应变值;运营隧道迎爆面拱顶及侧墙中部动力响应显著,邻近运营隧道衬砌的破坏主要是由质点振速超过安全允许值造成的;通过不同装药量爆破数值模拟结果的分析,提出了大帽山隧道原位扩建爆破最大段的控制药量。To control the blasting vibration effect of local continuation on the structure safety of an adjacent operation tunnel, a numerical analysis model was established based on the perspective of direct initiation of explosives by means of ANSYS / LS-DYNA software,with the project background of Damaoshan tunnel continuation of rare large section with small cycle distance. The blasting stress wave inside surrounding rock and operation tunnel lining was discussed. The numerical analysis showed that the rock failure strain made great effect on the simulation results. The reasonable failure strain value of surrounding rock was obtained by comparing the explosion cavity size from numerical simulation with empirical formulas. The dynamic response near the arc top and the side center in the secondary lining of operation tunnel against the explosion source was significantly. The failure mechanism of the adjacent operation tunnel was mainly caused by the larger vibration velocity than permissible safe value. The maximum cooperating charge amount was put forward through the numerical analysis results of local tunnel continuation.

关 键 词：隧道原位扩建 小净距隧道 爆破振动 安全允许振速 动力有限元 

分 类 号：U457.6[建筑科学—桥梁与隧道工程]