不同爆破开挖工况下盾构管片的响应分析  

Response Analysis of Shield Segments under Different Blasting Excavation Conditions

作　　者：王海亮[1] 赵华鹏 赵军 肖景鑫 石晨晨 WANG Hai-liang;ZHAO Hua-peng;ZHAO Jun;XIAO Jing-xin;SHI Chen-chen(Shandong University of Science and Technology,Qingdao 266590,China;Chengdu New Technology Blasting Engineering Co.,Ltd.of China Railway No.2 Group,Chengdu 610000,China;Blasting Safety Technology R&D Center of China Railway Group Limited,Chengdu 610000,China)

机构地区：[1]山东科技大学,青岛266590 [2]中铁二局集团成都新技术爆破工程有限公司,成都610000 [3]中国中铁爆破安全技术研发中心,成都610000

出　　处：《爆破》2023年第1期194-204,共11页Blasting

基　　金：国家自然科学基金资助项目(10672091)。

摘　　要：为分析联络通道爆破开挖时盾构管片的动力响应,基于青岛地铁8号线盾构区间工程,进行了现场振动监测,得出掏槽爆破对管片的振动影响最为强烈的结果。进而基于现场掏槽孔装药量利用MIDAS-GTS NX模拟软件建立三维模型,对联络通道出洞、进洞8种不同间距爆破作用下盾构管片的振动、应力的响应规律进行分析,得出:在相同的爆破间距下,相比于进洞爆破,出洞爆破对临近盾构隧道管片的振动影响更为强烈,最大振动速度是进洞爆破的2.9~3.4倍,且随间距的减小振速递增幅度增大;在安全允许振速20 cm·s^(-1)下,出洞爆破时爆破间距应大于5.0 m,进洞爆破时爆破间距应大于1.25 m,未开挖部分岩石采用非爆破法进行开挖;开口管片应力集中明显,最大主应力的位置随间距的减小,表现为矩形开口底部,到矩形开口侧边的横纵缝相交处,最后到矩形开口上部的两侧顶角;对联络通道与盾构隧道近接交叉部位管片的进行切割,形成的开口不完整结构会减弱自身内侧在爆破荷载下的最大主应力,但会造成自身外侧产生小范围的应力集中,使其成为盾构隧道衬砌结构最为薄弱的位置。In order to analyze the dynamic response of the shield segments during the blasting excavation of a connecting channel,on-site vibration monitoring has been conducted based on the shield interval project of Qingdao Metro Line 8.The measured blasting vibration data show that the cut holes have the strongest impact on the shield segment vibrations.Then,based on the on-site charge of the cut holes,the MIDAS-GTS NX simulation software is used to establish a three-dimensional model to analyze the vibrations and stresses of the shield segments with 8 different blasting distances from the exit and entry of the connecting channel.Compared with the entry blasting,the impact of the exit blasting on the vibrations of the adjacent shield tunnel is more intense under the same blasting distance,and the peak vibration velocity is 2.9~3.4 times that of the entry blasting.On the other hand,the growing rate of the peak vibration velocity also increases with the decrease of the distance.When the allowable vibration velocity is 20 cm·s^(-1),the blasting distance should be greater than 5.0 m at the exit and greater than 1.25 m at the entry.The rocks that have not been excavated are excavated with non-blasting methods.The stress concentration is the most obvious in the opening segments,but the position where the maximum principal stress is generated shifts from the bottom of the rectangular opening through the intersection of transverse and longitudinal seams on the side of the rectangular opening to the top corners of both sides of the upper part of the rectangular opening with the decrease of spacing.Cutting the segments at the intersection of the connecting channel and the shield tunnel will form an incomplete opening structure,which will weaken the maximum principal stress on its inner side under the blasting load,but will cause a small range of stress concentration on its outer side,making it the weakest position of the shield tunnel lining structure.

关 键 词：盾构管片 联络通道 爆破 振动 应力 数值模拟 

分 类 号：TD235[矿业工程—矿井建设]