基于HHT分析的超浅埋隧道下穿民房降振控爆技术研究

发布时间：2018-05-14 13:07

本文选题：HHT + 大跨浅埋　；参考：《西南交通大学》2015年硕士论文

【摘要】：在铁路隧道施工设计方面各施工设计单位已有丰富的经验和设计成果,但对于大跨度浅埋隧道,尤其是在复杂施工环境下施工的大跨浅埋隧道,仍有许多技术性难题需要解决。如何控制爆破震害,如何正确处理振动控制与工程效率间的矛盾,是施工首要解决的问题。本文针对仙女岩隧道进口端下穿民房密集区爆破振动控制技术难题,通过HHT方法分析现场监测数据。提出隧道60cm进尺掏槽设计方案并通过现场试验验证,同时提出80cm进尺掏槽微差降振方案和1.8米进尺掏槽微差联合干扰降振控爆方案。80cm进尺方案通过降低单段药量可有效控制地表振速,1.8m控爆方案采用掏槽空气轴向不耦合装药并采用微差起爆,可控制振速满足设计要求,但对地表构建筑物输入能量大于80cm进尺方案。这两种方法可在施工中就现场状况择优选用。运用HHT变换获得监测数据瞬时能量谱及边际谱,边际谱体现能量在频段内聚集特性,瞬时能量谱体现对构建筑的瞬时输入能量。振速越大、频率越低,能量越大,能量作为频率、振速以及振动时间的共同作用结果,更适合作为振动安全判别标准。仙女岩隧道是大跨超浅埋隧道,需要采取综合措施降振。可同时采取缩短进尺、人工开挖自由面、减少单段装药量等方法满足设计要求。干扰降振法核心为微差延时时间确立。本文采用数值模拟获得单段波形信号叠加所得微差最佳时间段为10-20ms,取用10ms间隔叠加所得振速较单段起爆降低12%,所得结果并非1/2周期叠加最优,只是叠加对单段信号峰值起到消峰作用。就仙女岩隧道施工难题提出0.6m进尺掏槽爆破方案,并现场验证施工可用。采用数值模拟软件进一步优化方案得到隧道80cm进尺掏槽微差爆破以及1.8m进尺轴向空气不耦合装药干扰降振爆破方案。对比本文提出的多种掏槽孔微差延时起爆以及不同装药量起爆所得的地表振速,分析得到临空面、单段药量及隧道埋深对地表振动有着重要影响。
[Abstract]:Various construction design units have rich experience and design results in railway tunnel construction design, but there are still many technical problems to be solved for long-span shallow buried tunnel, especially for long-span shallow buried tunnel under complex construction environment. How to control blasting damage and how to correctly deal with the contradiction between vibration control and engineering efficiency are the most important problems to be solved in construction. Aiming at the technical problem of blasting vibration control under the entrance end of Xianyan tunnel in dense residential area, the field monitoring data are analyzed by HHT method in this paper. The design scheme of tunnel 60cm cutting is put forward and verified by field test. At the same time, it is put forward that the vibration reduction scheme of 80cm cutting and the joint disturbance of 1.8m cutting and blasting control scheme .80cm feeding scheme can effectively control the vibration velocity of ground surface by reducing the charge of single section and the 1.8 m blasting control scheme by cutting air axial direction. Coupling charge and using millisecond detonation, The controllable vibration velocity meets the design requirements, but the input energy for the surface structure is larger than the 80cm scale scheme. These two methods can be selected for site conditions in construction. The instantaneous energy spectrum and the marginal spectrum of the monitoring data are obtained by HHT transform. The marginal spectrum reflects the energy accumulation in the frequency band and the instantaneous energy spectrum reflects the instantaneous input energy to the structural building. The larger the vibration velocity, the lower the frequency and the greater the energy. As a result of the joint action of frequency, vibration velocity and vibration time, energy is more suitable as the criterion of vibration safety. The Andromeda tunnel is a long span super shallow tunnel, so it is necessary to take comprehensive measures to reduce vibration. At the same time, the methods of shortening the ruler, digging the free surface manually and reducing the charge quantity of single section can meet the design requirements. The core of the disturbance reduction method is the establishment of differential delay time. In this paper, numerical simulation is used to obtain the optimum time interval of 10 ~ 20ms for the superposition of single section waveform signal, and the vibration velocity obtained by using 10ms interval stack is 12% lower than that of single stage initiation. The result is not optimal by 1 / 2 periodic superposition. Only the superposition of the single signal peak value plays a peak role. In view of the difficult problems in the construction of Xianyan tunnel, the blasting scheme of 0.6 m scale cutting is put forward, and the site verification construction is available. The numerical simulation software was used to further optimize the scheme to obtain the millisecond difference blasting of tunnel 80cm cutting and the 1.8 m length axial uncoupled air charge interference vibration reduction blasting scheme. Compared with the surface vibration velocities obtained from the delay detonation of different cut holes and the detonation with different charge, the surface near the empty surface is obtained, and the single charge and the tunnel depth have important influence on the surface vibration.
【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U455.4

【参考文献】