公路隧道下穿既有引水隧洞施工的风险评估  

Risk assessment on the construction of highway tunnel under the existing diversion tunnel

作　　者：韩露 HAN Lu(Water Conservancy Station in Yemachuan Town,Hezhang County,Bijie City,Bijie 553208,China)

机构地区：[1]贵州省毕节市赫章县野马川镇水利站,贵州毕节553208

出　　处：《水科学与工程技术》2023年第2期55-57,共3页Water Sciences and Engineering Technology

摘　　要：主要采用数值模拟研究方法,依托我国西南地区某受地震影响水电站引水隧洞实际工程,对公路隧道下穿现有引水隧洞施工展开风险评估,并提出相应控制措施。采用有限元软件进行数值模拟分析,考虑不同周围岩体级别、不同净间距下隧道爆破施工对引水隧洞振动响应和变形开裂的影响。结果表明,隧道底部中点处振动响应最剧烈,前50ms内振动速度响应波动最大且出现峰值。围岩等级越低或间距越大时,隧道振动响应越小,对比相关标准,不建议采取爆破施工,采取深孔全断面预注浆处理后引水隧洞的最大沉降量降低至0.95cm,裂缝开展满足控制要求。The paper adopts numerical simulation research method,based on the actual diversion tunnel project of a hydropower station affected by earthquake in southwest China,carries out risk assessment on the construction of highway tunnel under the existing diversion tunnel,and puts forward corresponding control measures.LS-DYNA was used for numerical simulation analysis,and the vibration and deformation cracking laws of diversion tunnels under different levels of surrounding rock and different net spacing of tunnel blasting were considered respectively.The main research conclusions of this paper are as follows:the blasting vibration analysis results show that the vibration response at measuring point 1 is the most severe,and the vibration velocity response fluctuates the most and reaches a peak in the first 50ms;The lower the grade of surrounding rock and the larger the spacing,the smaller the vibration response of tunnel.Compared with the Chinese and Japanese standards,the vibration response peaks are higher than the control level,so blasting construction is not recommended.The maximum settlement of the diversion tunnel is reduced to 0.95cm after adopting the optimized support scheme and the pre-grouting treatment of deep hole with full section.The crack development meets the control requirements and the lining of the diversion tunnel will not crack and seepage.The cracking analysis results show that the diversion tunnel develops cracks due to the influence of uneven settlement,and the development of cracks is mainly tension.

关 键 词：引水隧洞 振动爆破 有限元分析 变形开裂 

分 类 号：TV871[水利工程—水利水电工程]