浅埋隧道下穿高速公路爆破施工对稳定性的影响研究

发布时间：2018-07-16 22:39

【摘要】：随着我国高铁事业的高速发展和基础交通设施的不断完善,线路相互交错的情况不可避免。本文结合沈一丹客运专线大顶山隧道下穿沈丹高速段工程,采用现场监测与数值模拟的手段,对采用钻爆法开挖时爆破波对地表的震动效应、爆破震动对围岩及衬砌的影响以及振动波的衰减规律进行研究。该地区围岩为V级,岩体多为片状页岩,强风化、岩体破碎,节理发育、岩体条件差,爆破施工对地面高速公路的正常运营威胁较大。因此,首先开展了现场地表震动效应测试和地表及隧道围岩变形监测工作,对监测数据进行了分析,在此基础上,通过建立数值模型,对开挖过程中不同方向地表振速的衰减规律和地表位移场的影响进行了分析和预测并与最终实测结果进行对比。最后针对该地区围岩多含水平节理的情况,分析了节理接触行为和节理参数对爆破应力波的传播和地表沉降规律的影响。监测和分析结果表明,沈丹客运专线大顶山隧道下穿高速公路地表沉降和振速均在允许范围之内,爆破施工对围岩造成的扰动不大。对各方向振速分量的分析发现掏槽孔、辅助孔和周边孔爆破形成的地震波基本未产生叠加,因此能有效地判断出各段装药爆破所对应的地表振动速度幅值。沿隧道轴线掌子面前后各测点地表振动速度发现,已开挖区地表测点振动速度比掌子面前方大,用萨道夫斯基公式对前后地表的振速数据进行拟合发现,隧道掘进前方可用该公式进行预测(K=384.5,α=1.16),而后方误差较大。节理的法向刚度与透射系数和呈指数增加关系；在等效刚度相同的情况下,透射波振速随着摩擦系数增加而减小。提示爆破施工中应该特别注意对中隔壁连接处的监测和保护,防止由于应力集中和爆破施工扰动而产生过大位移。
[Abstract]:With the rapid development of high-speed rail industry and the continuous improvement of basic transportation facilities, the interlacing of lines is inevitable. Combined with the project of Dadingshan Tunnel in Dadingshan Tunnel of Shen-Yidan passenger dedicated Line, this paper, by means of field monitoring and numerical simulation, analyzes the vibration effect of blasting wave on the ground surface when excavating by drilling and blasting method. The influence of blasting vibration on surrounding rock and lining and the attenuation law of vibration wave are studied. The surrounding rock in this area is V grade, the rock mass is mostly shales, strong weathering, rock mass fragmentation, joint development, poor rock mass condition, blasting construction is a great threat to the normal operation of the surface highway. Therefore, first of all, ground motion effect test and deformation monitoring work of ground surface and tunnel surrounding rock are carried out, and the monitoring data are analyzed. On this basis, the numerical model is established. The attenuation law of surface vibration velocity in different directions and the influence of surface displacement field during excavation are analyzed and predicted and compared with the final measured results. Finally, the influence of joint contact behavior and joint parameters on the propagation of blasting stress wave and the law of surface subsidence are analyzed in view of the fact that there are many horizontal joints in surrounding rock in this area. The results of monitoring and analysis show that the ground subsidence and vibration velocity of Dadingshan Tunnel under Dadingshan Tunnel of Shendan passenger dedicated Line are within the allowable range and the disturbance of surrounding rock caused by blasting construction is not great. The analysis of vibration velocity components in different directions shows that the seismic waves formed by cutting hole, auxiliary hole and peripheral hole blasting are basically not superimposed, so the amplitude of the surface vibration velocity corresponding to the charge blasting can be effectively determined. It is found that the vibration velocity of the measured points in the excavated area is larger than that in the front of the surface along the tunnel axis. The velocity data of the front and rear surface are fitted with the Saadolski formula. The formula can be used to predict the tunneling front (KN 384.5, 伪 1. 16), but the rear error is large. The normal stiffness of joints increases exponentially with the increase of transmission coefficient, and the velocity of transmission wave decreases with the increase of friction coefficient when the equivalent stiffness is the same. It is suggested that special attention should be paid to the monitoring and protection of the joint between the middle and the next-door in blasting construction so as to prevent excessive displacement caused by stress concentration and blasting construction disturbance.
【学位授予单位】：东北大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U455.6

【参考文献】