【作者】 徐锐；

【导师】 张继春；

【作者基本信息】 西南交通大学 ， 建筑与土木工程， 2015， 硕士

【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。更多还原

【Abstract】 On the design and construction of railway tunnel, design units have a wealth of experience and design results. But for the large section in shallow tunnel, expecially under the complicated construction environment, there are still many technical problems need to be solved. It is the primary how to effectively control the vibration damage and correctly handle the contradictions between vibration control and efficiency of projects.Focusing on the technical problem of the requirement of surface vibration control when Xiannvyan tunnel under-travel the area packed with houses, two control blasting program, staged cutting and with the interference of seismic waves, were proposed in this thesis through analyzing on the field monitoring data in Hilbert-Huang Transform. The program that the single circle footage of tunnel is 80cm can effectively control surface vibration by reduce signle delay charge. And the other program of single circle footage is 1.8m, also can control the vibration by axial decoupling charging, but the energy inputting to the building is higher than the former. The two programs can be selected according to field.Getting marginal spectrum and instantaneous energy spectrum of the detection signal by HHT, marginal spectrum reflect the energy concentration in different frequency, and instantaneous energy spectrum performance the instantaneous input energy for buildings. Energy will be improved if vibration velocity become bigger and frequency become lower. Energy is more suitable to be as safety criteria for blasting vibration because it is the common reflection of both vibration velocity and frequency.For Xiannvyan tunnel with large section in super shallow, comprehensive measures should be taken to decrease vibration. Many measures such as shorten single circle footage, create free face artificially and reduce single delay charge can be taken together. The key of the interference of seismic waves is the selection of delay time. In this thesis, the best time range is 10-20ms by signal averaging that the single segment single obtained through the numerical simulation. Through superposition single segment single at intervals of 10s, the vibration velocity can reduce 12%, and the result is not the best when the intervals is 1/2 cycle,but causing the effect that the peak of single is eliminated.Stimulate tunneling blasting with 0.6m sectional blasting,80cm sectional blasting and 1.8m axial decoupling charging with the interference of seismic waves. And the result reflect the surface vibration velocity is influenced importantly by depth of tunnel, signle delay charge and new free face.更多还原