爆破荷载作用下浅埋隧道地表振动的空洞效应研究

发布时间：2018-05-29 23:02

本文选题：浅埋隧道 + 爆破振动　；参考：《西南交通大学》2017年硕士论文

【摘要】：采用钻爆法进行隧道掘进施工的过程中,爆破施工产生的振动被认为是影响最大的负面效应。在浅埋隧道工程的爆破施工中,由于隧道的埋深较浅,导致地表的振动效应比较明显。如果不了解爆破地震波在地表的传播规律,就有可能导致地表的建筑物因过大的振动强度而发生破坏,造成严重的工程事故。空洞效应导致浅埋隧道爆破开挖时地表的振动发生区域性变化的特征,即隧道掌子面后方开挖成洞区拱顶上方地表的振动速度大于对称位置未开挖区的地表振动速度的现象。本文主要以成贵高铁豆子湾隧道下穿桥桥湾水库为工程背景,通过对隧道上方地表进行振动测试试验和数值模拟计算相结合的方法,进行爆破荷载作用下浅埋隧道地表振动的空洞效应研究。对现场试验测得的地表振动速度波形图进行分析,得到掏槽孔起爆引起的地表振动速度最大,掏槽孔起爆引起的振动对地表振动强度起决定性作用。提出空洞效应振速放大系数作为衡量空洞效应导致的地表振动放大效应的标准。进行数值模拟研究,提出爆破荷载的施加方法和边界条件的处理措施,得到进行爆破荷载作用下浅埋隧道地表振动研究的数值模拟方法,对计算结果进行分析得到空洞效应在隧道掘进方向上的变化规律和隧道上方地表受空洞效应影响的区域范围。提出分段楔形掏槽的掏槽孔起爆方法来削弱空洞效应导致的地表振动的放大效应,并在广州地铁二十一号线区间隧道上进行应用实践。
[Abstract]:In the process of tunneling construction by drilling and blasting, the vibration produced by blasting construction is considered to be the most negative effect. In the blasting construction of shallow tunnel engineering, the vibration effect of the ground surface is obvious because of the shallow buried depth of the tunnel. If we do not understand the propagation law of blasting seismic wave on the surface of the earth, it is possible to cause the destruction of buildings on the surface due to excessive vibration intensity and cause serious engineering accidents. The cavitation effect leads to the regional variation of the surface vibration during the blasting excavation of shallow buried tunnel, that is, the vibration velocity of the surface above the arch roof is higher than that of the unexcavated area in the symmetrical position after the excavation of the tunnel surface behind the face of the tunnel. In this paper, based on the engineering background of Qiaqiao Bay Reservoir under the Douzi Bay Tunnel of Chenggui High-speed Railway, the vibration test and numerical simulation of the surface above the tunnel are carried out. The cavity effect of shallow tunnel surface vibration under blasting load is studied. By analyzing the waveform of surface vibration velocity measured by field test, it is found that the surface vibration velocity caused by cutting hole initiation is the largest, and the vibration caused by the opening hole detonation plays a decisive role in the surface vibration intensity. The magnification factor of cavity effect is put forward as the criterion to measure the effect of surface vibration amplification caused by cavity effect. In this paper, numerical simulation is carried out, and the method of applying blasting load and the treatment of boundary condition are put forward, and the numerical simulation method of surface vibration of shallow buried tunnel under blasting load is obtained. Based on the analysis of the calculated results, the variation of cavitation effect in the tunneling direction and the range of the area affected by the cavitation effect on the surface above the tunnel are obtained. In this paper, a new method is proposed to reduce the amplification effect of surface vibration caused by cavity effect, and the method is applied to the tunnel of Guangzhou Metro Line 21.
【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U455.6

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