轻轨隧道开挖引起的铁路路基与边坡等构筑物爆破地震效应及其控制

发布时间：2018-04-26 01:03

本文选题：轻轨隧道 + 爆破地震效应　；参考：《湖南科技大学》2015年硕士论文

【摘要】：随着我国交通基础建设的蓬勃发展,在多山和丘陵地区修建高速公路,高速铁路,在城市中修建轻轨已经势在必行,采用钻爆法开挖各种公路隧道、铁路隧道、轻轨隧道也应用而生,同时爆破开挖过程中产生的爆破地震效应也越来越受到人们的关注。本文以宁波市轨道交通1号线二期育王岭隧道工程为依托,通过现场监测结果分析以及运用ANSYS/LS-DYNA动力分析软件进行数值模拟分析,展开了对隧道爆破引起的铁路路基、边坡等构筑物地震效应及其控制研究,得出了如下结论:(1)开展了依托工程爆破振动观测测试与分析,得到了宁波地区轻轨隧道爆破地震波传播和衰减规律。通过观测结果回归分析,得到了较近距离地表、较远距离铁路路基垂直方向、水平径向、水平切向的质点振动速度峰值随炸药药量与距离衰减的经验公式。(2)通过爆破地震波时频特性分析、远近距离对比分析指出,较远距离爆破振动衰减指数比较近距离的明显要大,衰减指数会随着距离的增加而增大;较近距离地表的质点振动主振频率主要集中在20~30Hz,而较远距离铁路路基的质点振动主振频率主要集中在10~20Hz。(3)建立了轻轨隧道爆破开挖数值模拟模型,进行了隧道爆破开挖影响下铁路路基与边坡等构筑物动力响应分析。结果表明,铁路路基与隧道爆破开挖位置平齐时,质点振动速度衰减缓慢、峰值出现相对较晚,水平切向分量与振动速度矢量和吻合较好;沿铁路路基中部断面两侧的质点振动速度先随距离有一定量衰减,但随后的衰减规律并不明显。(4)边坡动力响应分析结果表明,边坡上质点振动速度衰减较快,且质点振动速度峰值出现较早,水平切向分量与振动速度矢量和吻合较好;不同高度上的坡体特征点质点振动速度峰值随高度的变化并不明显,但在坡肩上有一个明显的放大效应。(5)基于爆破振动安全监测及其分析、轻轨隧道爆破开挖影响下的铁路路基与边坡动力响应分析,针对依托工程的工程地质、环境条件以及施工方法与施工工艺等,研究提出了改变开挖方法、合理控制爆破开挖进尺、选择合理的装药结构、确定最佳炸药单耗、合理控制掏槽孔药量等爆破地震效应控制方法。
[Abstract]:With the rapid development of the traffic infrastructure in China, it is imperative to build the highways in the mountainous and hilly areas, the high speed railway, and the construction of light rail in the city. The drilling and blasting method is used to excavate a variety of highway tunnels, railway tunnels and light rail tunnels are also applied, and the blasting seismic effects produced in the process of blasting excavation are also getting more and more popular. In this paper, based on the two period Yu Wang Ling tunnel project of Ningbo Rail Transit Line 1, the seismic effect and control of the railway subgrade, slope and other structures caused by tunnel blasting are studied through the analysis of the field monitoring results and the numerical simulation analysis using the ANSYS/LS-DYNA dynamic analysis software. Conclusions: (1) the propagation and attenuation laws of blasting seismic waves in Ningbo light rail tunnel are obtained by the observation and analysis of blasting vibration observation and analysis. Through the regression analysis of the observation results, the vertical direction of the railway subgrade, the horizontal diameter direction and the peak value of the horizontal tangential velocity with the explosive charge are obtained by the regression analysis of the observation results. The empirical formula of distance attenuation. (2) through the analysis of the time-frequency characteristics of blasting seismic waves, the far and near distance comparison analysis indicates that the vibration attenuation index of far distance blasting is obviously larger than that of the distance, and the attenuation index will increase with the increase of distance; the main vibration frequency of the mass point vibration of the nearer ground surface is mainly concentrated in 20~30Hz and far distance. The main vibration frequency of the particle vibration from the railway subgrade is mainly concentrated in 10~20Hz. (3) to establish the numerical simulation model of the light rail tunnel blasting excavation, and the dynamic response analysis of the railway subgrade and slope under the influence of tunnel blasting excavation is carried out. The results show that the vibration velocity of the mass point is slowly attenuated when the railway subgrade and the tunnel blasting excavation position is flat. Slow, the peak value appears relatively late, the horizontal tangential component and the vibration velocity vector and coincide well, the vibration velocity along the side of the middle section of the railway subgrade is attenuated with a certain amount of distance, but the subsequent attenuation law is not obvious. (4) the result of the slope dynamic response analysis shows that the velocity of the particle vibration attenuation on the slope is faster, and the particle vibration is vibrate. The peak value of the dynamic velocity appears earlier, the horizontal tangential component and the vibration velocity vector are in good agreement. The variation of the peak vibration velocity of the characteristic point of the slope body at different heights is not obvious with the height, but there is a significant amplification effect on the slope shoulder. (5) based on the safety monitoring and analysis of blasting vibration, the influence of the blasting excavation of the light rail tunnel is influenced by the blasting excavation. The dynamic response of railway subgrade and slope is analyzed. In view of the engineering geology, environmental conditions, construction methods and construction technology, it is proposed to change the excavation method, rationally control the blasting excavation step, select the reasonable charge structure, determine the best explosive unit consumption, and control the charge of the hole, and so on. Law.

【学位授予单位】：湖南科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U213.1;U456.3;TU311.3

【参考文献】