无中墙连拱隧道爆破振动监测和安全控制方法  

Blasting Vibration Monitoring and Safety Control Method for Double Arch Tunnel without Middle Wall

作　　者：茶增云 范孝刚 肖振江 孟德生 和振海 孙印国 廖明进[6] CHA Zeng-yun;FAN Xiao-gang;XIAO Zhen-jiang;MENG De-sheng;HE Zhen-hai;SUN Yin-guo;LIAO Ming-jin(Yunnan Menglu Expressway Investment and Development Co.,LTD.,Pu'er 665000,China;Yunnan Communications Investment Group Investment Co.,LTD.,Kunming 650100,China;Yunnan Jiaofa Highway Engineering Co.,LTD.,Kunming 650041,China;State Key Laboratory of Geomechanics and Geotechnical Engineering,Institute of Rock and Soil Mechanics,Chinese Academy of Sciences,Wuhan 430071,China;China Railway Development and Investment Group Co.,LTD.,Kunming 650500,China;Wuhan University of Science and Technology,Wuhan 430081,China)

机构地区：[1]云南勐绿高速公路投资开发有限公司,普洱665000 [2]云南交投集团投资有限公司,昆明650100 [3]云南交发公路工程有限公司,昆明650041 [4]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实验室,武汉430071 [5]中铁开发投资集团有限公司,昆明650500 [6]武汉科技大学,武汉430081

出　　处：《爆破》2022年第3期64-70,138,共8页Blasting

基　　金：云南省交通运输厅科技创新及示范项目(云交科教[2019]79号)。

摘　　要：无中墙连拱隧道作为一种新的隧道形式由于其两拱相连,间距过小,导致后行洞爆破施工时对先行洞支护结构及围岩易产生不利影响,需要对爆破进行监测及安全控制。以云南曼腊公路隧道为依托,通过现场实测数据与数值模拟结果相结合,对后行洞爆破开挖进行分析研究。在后行洞爆破施工过程中对先行洞洞壁振动速度进行监测,得到该工程地质条件下后行洞爆破时先行洞洞壁振动速度的传播和衰减规律。建立数值模型,模拟连拱隧道后行洞爆破开挖的施工过程,对模型计算得到的振动速度传播的衰减规律与现场实测数据进行比对,确保离散元模型的可靠性与准确性。对模型中后行洞爆破开挖对先行洞衬砌变形和围岩损伤进行分析,得到衬砌支护结构和围岩的稳定性。综合振动传播规律和数值模拟结果,在确保支护结构和围岩安全的前提下提出针对该隧道的最大段药量,在该工程条件下,建议后行洞爆破时最大段药量不超过15 kg。结合最大段药量和振动衰减规律确定最大允许振动速度,于爆破工作面同一平面的先行洞迎爆侧中墙处振动速度不超过22 cm/s。在后续施工中该安全控制方法可靠有效,可为类似连拱隧道爆破开挖工程提供参考。As a new type of tunnel,a double-arch tunnel is connected by two arches without a middle wall.And too small a distance between them leads to a situation that the blasts in the subsequently excavated tunnel inevitably affect the support structure and surrounding rock of the antecedently excavated tunnel.So,it is necessary to monitor and control the blasting construction.Based on the Manla highway tunnel in Yunnan province,the blasting excavation of the subsequently excavated tunnel is studied by combining field test data with numerical simulation results.Blast vibrations of the antecedently excavated tunnel wall were first monitored during the blasting construction of the subsequently excavated tunnel to analyze the corresponding propagation and attenuation laws.Then,a numerical model was established to simulate the construction process of blasting excavation in the subsequently excavated tunnel,and the attenuation law of vibration propagation calculated by the model is compared with the field measured data to ensure the reliability and accuracy of the discrete element model.By analyzing the lining deformation and surrounding rock damage caused by blasting excavation in the model,the stability of lining supporting structure and surrounding rock is obtained.Based on the vibration propagation law and numerical simulation results,the maximum charge per delay for the tunnel is proposed on the premise of ensuring the safety of supporting structure and surrounding rock.Under the engineering conditions,it is suggested that the maximum charge per delay for the subsequently excavated tunnel should not exceed 15 kg.The maximum allowable vibration velocity is determined by combining the maximum charge per delay and vibration attenuation law,and the vibration velocity at the middle wall of the blasting side of the antecedently excavated tunnel on the same plane of the blasting working face is no more than 22 cm/s.The safety control method is reliable and effective in subsequent construction,which can provide reference for sim

关 键 词：连拱隧道 振动监测 振动衰减规律 离散元 衬砌变形 围岩损伤 安全控制方法 

分 类 号：TD235.3[矿业工程—矿井建设]