# Blasting Vibration Control and Signal Analysis of Adjacent Existing Deterioration Tunnels
## 1 Introduction  
With the continuous development of railway construction scale in our country, it is inevitable that new railway tunnels will come close to or cross existing lines. Existing tunnels with a long service life will have cracks and other deterioration phenomena appear under weathering and long-term train load. The stability of the deteriorated tunnel is reduced under the action of blasting load. Therefore, taking vibration reduction measures to reduce vibration at the source of the explosion is the key to ensuring the safety of existing deterioration tunnels. At present, the vibration reduction methods used in engineering mainly include control of maximum charge, differential blasting, staggered peak vibration reduction, and so on. Certain effects of vibration reduction can be obtained after corresponding measures are taken for different site conditions. In the blasting construction of the tunnel, [PERSON] [1] and [PERSON] [2] calculated the amount of explosive charge using the Sadovsky formula linear regression method and effectively controlled the blasting vibration velocity within the safe range; [PERSON] [3] and [PERSON] [4], respectively, used three-step blasting and double-step blasting toreduce the blasting vibration effect of urban underground tunnel construction. [PERSON] [5] and [PERSON] [6] pointed out that the key to decreasing the vibration of differential blasting is the control of differential time. [PERSON] [7] and [PERSON] et al. [8] used ANSYS/LS-DYNA software, version 19.2, to simulate the reasonable micro-difference time between deep hole blasting and shallow hole blasting. It is proved that the precision delay between holes based on a digital electronic detonator is better than the simultaneous detonation of holes. [PERSON] [9] found that the main vibration period of the digital electronic detonator can be staggered by half a cycle to reduce the blasting vibration. In addition to common vibration reduction measures, many scholars have also made innovations for specific projects. [PERSON] et al. [10] proposed a four-part excavation method. [PERSON] et al. [11] proposed setting vibration damping holes for vibration control. The double-layer hole layout suitable for the project is finally obtained. [PERSON] [12] pointed out that, for shallow buried tunnels, the use of digital electronic detonators for delayed blasting is not as effective as the use of electronic detonators in deep buried tunnels. Therefore, this paper proposes a new blasting method: mechanical cutting combined with detonators. With the development of science and technology, traditional Fourier transform cannot meet the requirements. Therefore, in the 1980s, wavelet transform was proposed by French scientists. Then, it gradually developed into a very important means in the field of signal processing. [PERSON] et al. [13] used a wavelet packet to analyze the frequency and energy distribution of vibration signals under each cut mode. In order to reduce the noise of blasting vibration signals, [PERSON] [14] and [PERSON] et al. [15] used wavelet packet analysis to further decompose the mode function of vibration signals into a series of wavelet packet coefficients of different scales. [PERSON] et al. [16] used wavelet packet transform with multi-resolution characteristics to decompose blasting signals in multiple layers and obtained detailed information on energy distribution. Aiming at the shortcomings of the Fourier transform in the analysis of non-periodic and non-stationary signals, [PERSON] et al. [17] proposed a calculation method for wavelet packet transform. This method accurately describes the frequency characteristics of blasting signals and effectively overcomes the disadvantages of the Fourier transform. [PERSON] et al. [18] used wavelet packet transform to analyze the time-frequency characteristics of the measured vibration signal, and the energy distribution characteristics of the vibration signal frequency band were obtained.