scholarly journals Propagation Laws of Blasting Seismic Waves in Weak Rock Mass: A Case Study of Muzhailing Tunnel

2020 ◽  
Vol 2020 ◽  
pp. 1-15
Author(s):  
Lijun Chen ◽  
Jianxun Chen ◽  
Yanbin Luo ◽  
Yalong Guo ◽  
Yongjun Mu ◽  
...  

In order to study the propagation laws of blasting vibration waves in weak rock tunnels, the longitudinal and circumferential blasting vibration tests in Muzhailing Tunnel were carried out, and the measured data were analyzed and studied using the methods of Sadov’s nonlinear regression, Fourier transform, and Hilbert–Huang transform (HHT) to provide a reference for the optimization of blasting design of Muzhailing Tunnel or similar weak rock tunnels. The results showed that the tangential main frequency decreases rapidly and the radial main frequency decreases slowly with the increase of proportionate charge quantity. Under a certain charge quantity, as the distance from the explosion source increases, the spectrum width of the blasting vibration frequency becomes narrower, the overall energy is more concentrated, and the vibration frequency tends to be closer to the low frequency. At a certain distance from the explosive source, the frequency of blasting vibration decreases gradually, and the amplitude of low-frequency region increases with the increase of charge quantity. The vibration velocity on the left side of the tunnel is larger than that on the right side, and the vibration velocity at the vault and the arch foot of lower bench decreases rapidly, while the vibration velocity at the arch feet of upper bench and middle bench decreases slowly. The vibration frequencies of the left arch foot of the middle bench and the right arch foot of the upper bench are higher than those of other positions, while the frequencies of the left arch foot of the upper bench are the lowest. During tunnel blasting, the energy input to the strata media is mainly concentrated in the stage of the blasting of the cut hole. The blasting has more energy input to the left arch foot of the upper bench and the tunnel vault, which is consistent with the conclusion of frequency analysis.

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Huaibao Chu ◽  
Xiaolin Yang ◽  
Shuanjie Li ◽  
Weimin Liang

The propagation and attenuation rule of blasting vibration wave parameters is the most important foundation of blasting vibration prediction and control. In this work, we pay more attention to the influence of the damage accumulation effect on the propagation and attenuation rule of vibration wave parameters. A blasting damage accumulation experiment was carried out, the ultrasonic wave velocity of the specimens was measured, and the damage value was calculated during the experiment. The blasting vibration wave was monitored on the surface of the specimens, and its energy was calculated by using the sym8 wavelet basis function. The experimental results showed that with the increase in the number of blasts, the damage continues to increase; however, the vibration velocity and the main frequency decrease continuously, the unfocused vibration wave energy in the zone near to the blasting source is rapidly concentrated in the low-frequency band (frequency bands 1 to 3), and the energy is further concentrated in the low-frequency band in the intermediate zone and zone far from the blasting source. There is a distortion process in which the vibration velocity and the main frequency increase slightly and the energy of the blasting vibration wave converges to the high-frequency band (the 5th band) before the sudden unstable fracture failure of the specimens. The experimental results indicate that the prediction and evaluation of blasting vibration should consider the variation rule of blasting vibration wave parameters synthetically based on the cumulative damage effect, and it is not safe to use only one fixed vibration control standard for the whole blasting operation.


2012 ◽  
Vol 204-208 ◽  
pp. 1405-1408
Author(s):  
Wen Xue Gao ◽  
Xi Meng Sun ◽  
Bing Hui Hou ◽  
Ning Ning Chen

Based on Huolangyu tunnel of Mixing road, this paper researches the monitoring of ground surface vibration and the technology of controlled blasting. Monitoring and analysis results show: The ground surface vibration decline from constructed position to un-constructed position along tunnel excavation direction. The maximum ground surface vibration locates at the shallow position along tunnel cross section. The surface vibration velocity main vibration frequency has more than one advantage frequency, main vibration frequency concentration distribution in 20~40Hz low frequency band. Tunnel driving, the emphasis of the blasting vibration should focus on control of tunnel excavation area has the upper, lining structure and shallow buried in the influence of the surrounding rock; Tunnel through the surface buildings, cannot ignore already forming of blasting seismic effects of tunnel amplification and resonance effect.


2010 ◽  
Vol 163-167 ◽  
pp. 2613-2617
Author(s):  
Hai Liang Wang ◽  
Tong Wei Gao

According to the 33 floors high building, blasting vibration monitoring had been carried on. The building, along Yunnan road tunnel of Qingdao Cross-harbor Tunnel Guide Line Project, has concrete frame structure. Monitoring data had been analyzed. Results showed that rules of vertical vibration velocity and main vibration frequency have similar relevance. Amplification effect of them was existed on the middle and top of the building. From the 2nd floor of downward ground to ground, the value of them suddenly decreased. Main vibration frequency is in the range of 101~102 order of magnitude.


2015 ◽  
Vol 744-746 ◽  
pp. 982-987
Author(s):  
Yong Ming Han ◽  
Yi Zhou ◽  
Hai Liang Wang

Put the first Phase Project of Qingdao Metro (line 3) civil 03 bid section TAI-YAN interval of blasting construction as the background In this paper,select the test section to blasting test,in groundposition on the ais of the tunnel workface arrange the measuring points and location of measuring points remain the same.Based on the measured data, studied on the law of blasting vibration of cutting parts of each of the driving cycle.The research result show that the cutting part of vibration velocity peak appeared in behind the tunnel woekface 1~3m;Rear vibration composite speed of the tunnel workface is speed of the tunnel workface is 1.0~1.4 times in front of the particle vibration composite speed;The main vibration frequency in front of tunnel workface and rear particles are above 15HZ.


2012 ◽  
Vol 446-449 ◽  
pp. 2462-2465 ◽  
Author(s):  
Hong De Wang ◽  
Xiu Feng Shen

Abstract. Through the analysis and research on the vibration effect caused by the urban New Austrian (shallow embedded) metro tunnel blasting construction, the main harming effect of the blasting vibration on the surface buildings is summarized. According to the actual condition on the site of blasting construction in No.2 line of Dalian metro tunnel, the reasonable vibration monitoring plan for blasting vibration wave is established. At the same time, by means of the regression analysis about the monitoring results of blasting vibration, the vibration wave’s regression formula are set up, which can expression the correlation among the vibration velocity, the charge weight, the distance between the blasting fountains and the buildings. The results show that the Sadaovsk formula can be use to describe the effect of the metro tunnel blasting construction on the surface buildings accurately and reasonably in this construction segment. This kind of regression analysis method can be use to direct subsequent blasting excavation.


2011 ◽  
Vol 199-200 ◽  
pp. 870-873
Author(s):  
Hai Liang Wang ◽  
Shu Cui Cong ◽  
Bi Jun Wang ◽  
Lin Sheng Liu

According to the tunnel blasting vibration test at Kiaochow bay Cross-harbor Tunnel Guide Line Project, the regulation of the tunnel vibration velocity has been studied. Based on the analytical results, this paper finds that the change regulation of vertical, horizontal radial and tangential vibration velocity as the different distances from the work face. The tunnel vibration velocity of the rear work face is greater than the unexcavated area. The peak value of the rear work face is 2-2.5 times as large as that of the front work face, vibration velocity of the front work face attenuates gently. The paper figures out the relationship between vibration velocity and distance from sensor to the work face, which can offer a reference to similar studies.


2021 ◽  
Vol 12 (1) ◽  
pp. 12
Author(s):  
Fan Chen ◽  
Gengsheng He ◽  
Shun Dong ◽  
Shunjun Zhao ◽  
Lin Shi ◽  
...  

The vibration produced by blasting excavation in urban underground engineering has a significant influence on the surrounding environment, and the strength of vibration intensity involves many influencing factors. In order to predict the space-time effects of blasting vibration more accurately, an automatic intelligent monitoring system is constructed based on the rough set fuzzy neural network blasting vibration characteristic parameter prediction model and the network blasting vibrator (TC-6850). By setting up the regional monitoring network of monitoring points, the obtained monitoring data are analyzed. An artificial intelligence model is used to predict the influence of stratum condition, excavation hole, and high-rise building on blasting vibration velocity and frequency propagation. The results show that the artificial intelligence prediction model based on a rough set fuzzy neural network can accurately reflect the formation attenuation effect, hollow effect, and building amplification effect of blasting vibration by effectively fuzzing and standardizing the influencing factors. The propagation of blasting vibration in a soil–rock composite stratum is closely related to the surrounding rock conditions with a noticeable elastic modulus effect. The hollow effect is regional, which has a significant influence on the surrounding ground and buildings. Besides, the blasting vibration of the excavated area is stronger than that of the unexcavated area. The propagation of blasting vibration on high-rise buildings was complicated, of which the peak vibration velocity is maximum at the lower level of the building and decreased with the rise of the floor gradually. The whip sheath effect appears at the top floor, which is related to the blasting vibration frequency and the building’s natural vibration frequency.


2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Ke Man ◽  
Xiaoli Liu ◽  
Zhifei Song

Based on the blasting principle of the cutting seam cartridge, smooth blasting with the charge structures of the usual cartridge and cutting seam cartridge has been designed and implemented, respectively, for different peripheral holes in the same face. Meanwhile, the blasting vibration has been monitored. Through the analysis of the frequency spectrum of blasting vibration signals, it is found that the maximum blasting vibration velocity of the cutting seam cartridge charge is lower than that of the usual cartridge charge, from 0.21 m/s to 0.12 m/s. Moreover, the blasting energy distribution is more balanced. Especially in the low-frequency part, the blasting energy is less, and there is a transferring trend to the high-frequency part, which shows that the cutting seam cartridge charge has a better optimization effect. Furthermore, using wavelet packet analysis, the cutting seam cartridge charge could effectively reduce the energy concentration in the low-frequency part. The energy distribution is much more dispersed, and the disturbance to the structure could be less, which is conducive to the stability of the structure. According to the blasting effect, the overbreak and underexcavation quantity at the cutting seam cartridge charge is better than that at the usual cartridge charge.


2011 ◽  
Vol 90-93 ◽  
pp. 2301-2306
Author(s):  
Zheng Guo Zhu ◽  
Ming Lei Sun ◽  
Yong Quan Zhu ◽  
Xing Liang Sun

In accordance with characteristics of super-small-distance tunnels in Nanjing metro, the peak value distribution of vibration velocity for existing tunnel was investigated when cut-hole blasted under the conditions of different surrounding rock Grades, followed by dynamic response rule of super-small-distance tunnels blasting. In addition, monitoring emphasis should be placed on upper bench for right tunnel blasting. Therefore, controlled measures of the small-distance tunnels were obtained during construction. Not only is the result fit for the metro tunnel, but it can be as reference for similar engineering.


2014 ◽  
Vol 971-973 ◽  
pp. 992-996
Author(s):  
Chun Lei Xin ◽  
Bo Gao

Although drilling and blasting method is widely used to excavate tunnel structures, it has great effect on adjacent ground structures. In order to find out the influence sphere and features of this construction method on overpass, three-dimensional numerical simulation method was used to analyze the displacement, stress and blasting vibration velocity of overpass. The results show that: (1) Drilling and blasting excavation method can cause differential settlement of stratum and overpass which is above the crown of tunnel. (2) The strong constraint structures of overpass are obviously affected by blasting vibration than other parts. (3) It should be taken extra protection measures at connection points between piers and decks as well as connection points between piers and stratum. (4) Horizontal vibration velocity caused by blasting excavation is lower than vertical vibration velocity. To control the vertical blasting vibration velocity is the essential to control the security of tunnel structure and upper structures. The above results certainly contribute to construct tunnel structures by using drilling and blasting excavation under complicated conditions.


Sign in / Sign up

Export Citation Format

Share Document