scholarly journals Blasting Energy Analysis of the Different Cutting Methods

2018 ◽  
Vol 2018 ◽  
pp. 1-13 ◽  
Author(s):  
Ke Man ◽  
Xiaoli Liu ◽  
Ju Wang ◽  
Xiyong Wang
Keyword(s):  
High Frequency ◽  
Low Frequency ◽  
Vibration Velocity ◽  
Blasting Vibration ◽  
Double Wedge ◽  
Factors Affecting ◽  
Good Utilization ◽  
Smooth Blasting ◽  
Blasting Method ◽  
Parallel Hole

Based on the smooth blasting method, the blasting parameters of the Beishan exploration tunnel have been designed. According to the principle of blasting parameters design, three kinds of cutting methods have been laid out, which are straight parallel hole cutting, single-wedge cutting, and double-wedge cutting. The other parameters such as the borehole number, the detonator segment, and the charge amount of each hole are also designed. Then, the blasting tests under different cutting methods were carried out in the field. The results show that all the three cutting methods can achieve good utilization ratio of blasting holes. The blasting effect of straight parallel hole cutting is good. The rock slag size of single-wedge and double-wedge cutting is uniform, which is beneficial to slag extraction. Moreover, the blasting vibration velocity and blasting energy have been analyzed. It is found that the energy distribution of single-wedge and double-wedge cutting is more uniform, mainly concentrated in the high-frequency part, while the energy of straight parallel hole cutting is more concentrated in the low-frequency part. Among many factors affecting blasting vibration velocity, besides the explosive quantity, it would also be easily influenced by the cutting way. It should be noticed that the blasting method includes numerous blasting parameters, which interact with each other. Those blasting parameters obtained were just limited to the cutting method, and the result and the theoretical knowledge could be applied to the blasting and excavation of the deep geoengineering and the HLW geo-disposal.

scholarly journals Frequency Spectrum and Wavelet Packet Analyses of Blasting Vibration Signals for Different Charge Structures in Blasting Peripheral Holes

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Ke Man ◽  
Xiaoli Liu ◽  
Zhifei Song
Keyword(s):  
Energy Distribution ◽  
Frequency Spectrum ◽  
Wavelet Packet ◽  
Low Frequency ◽  
Energy Concentration ◽  
Vibration Velocity ◽  
Blasting Vibration ◽  
Vibration Signals ◽  
The Stability ◽  
Smooth Blasting

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.

scholarly journals Experimental Investigation of the Propagation and Attenuation Rule of Blasting Vibration Wave Parameters Based on the Damage Accumulation Effect

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Huaibao Chu ◽  
Xiaolin Yang ◽  
Shuanjie Li ◽  
Weimin Liang
Keyword(s):  
Frequency Band ◽  
Damage Accumulation ◽  
Low Frequency ◽  
Experimental Results ◽  
Vibration Velocity ◽  
Blasting Vibration ◽  
Main Frequency ◽  
Wave Parameters ◽  
Accumulation Effect ◽  
Vibration Wave

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.

Study on Energy Distribution of Single-Hole Blasting Vibration Signal Based on Wavelet Packet Transform

2013 ◽  
Vol 321-324 ◽  
pp. 1284-1289
Author(s):  
Dong Tao Li ◽  
Li Xin Xu ◽  
Yuan Yuan Sun ◽  
Qiu Rui Jia ◽  
Jing Long Yan
Keyword(s):  
Energy Distribution ◽  
Concentration Distribution ◽  
Wavelet Packet ◽  
Low Frequency ◽  
Vibration Signal ◽  
Vibration Velocity ◽  
Blasting Vibration ◽  
Wavelet Packet Analysis ◽  
Vibration Signals ◽  
Single Hole

It is conducive to reducedamage of blasting vibration to realize energy distribution and attenuation lawof single-hole blasting vibration signal. With the measured single-holeblasting vibration velocity curves, used wavelet packet analysis technologywith high-resolution character, the law of energy distribution of single-holeblasting vibration signals in different frequency bands, and the effect ofblasting source and distance from the source on single-hole blasting vibrationsignal energy distribution were analysised. The results show that the energy ofsingle-hole blasting vibration signals attenuation very quickly in thefrequency domain concentration distribution in 0~100Hz; and distance from thesource has significant influence on energy distribution in the frequencydomain; The energy is mainly distributed in the low frequency band whendistance from the source is larger, which has guiding significance inmitigation of blast-induced vibrations.

On Vibrational and Dynamic Characteristics of Engines with Deactivated Cylinders

2020 ◽  
pp. 26-34
Author(s):  
A.I. Yamanin
Keyword(s):  
Dynamic Characteristics ◽  
High Frequency ◽  
Low Frequency ◽  
Vibration Velocity ◽  
Toxic Substances ◽  
Vibration Displacement ◽  
Engine Torque ◽  
High Frequency Vibration ◽  
Low Frequency Vibration ◽  
Loading Modes

The article examines some features of dynamics of engines with shut-off cylinders. This technology can promote reduction of fuel consumption and emission of toxic substances with exhaust fumes at partial speed and loading modes. However, the dynamics of such engines have hardly been considered in previous works. Using calculations (solid state modeling, simulation of motion using software for studying dynamics of mechanisms, as well as the finite element method), the indicators of uniformity of stroke and torque, vibration displacement and vibration velocity of various points of the structure at low- and high-frequency vibration are determined. It is shown that when deactivating a different number of cylinders, the uniformity of the engine torque worsens (to a varying degree) and the load on the crankshaft bearings increases. The average quadratic values of vibration velocity of the bearings at low-frequency vibration and the vibration velocity of the lateral walls of the housing parts at high-frequency vibration increases as well. While engines with deactivated cylinders definitely have advantages in efficiency and environmental performance, they do not improve vibrational and dynamic characteristics, which is particularly evident at low rotational speeds of the shaft and at small loads.

Еxperimental Studies of Sliding Bearings of Locomotive Turbochargers by Their Level of Vibration

2018 ◽  
Vol 7 (4.3) ◽  
pp. 81
Author(s):  
Andrii Pogrebnyak ◽  
Andrii Yеvtushenko ◽  
Andrii Кravets ◽  
Artem Kovtunenko ◽  
Igor Tilichko
Keyword(s):  
High Frequency ◽  
Vibration Spectrum ◽  
Experimental Studies ◽  
Low Frequency ◽  
Vibration Velocity ◽  
Diesel Locomotive ◽  
Diagnostic Features ◽  
Sliding Bearings ◽  
Low Frequency Vibration ◽  
Free Bearing

The diagnostic features and sources of vibration of sliding bearings of diesel locomotive turbochargers (disappearance of the negative allowance on bearing bushings, self-oscillation in the bearing, self-oscillation when the negative allowance on the bearing bushing disappears, excitation of blade harmonics, etc.) are described in brief. The results of experimental studies of diesel locomotive turbochargers equipped with cylindrical and elliptical sliding bearings are shown. The specific spectra of vibration velocity of the bearing housings (cylindrical and elliptical) in the low-frequency range are presented. Bearing frequencies have been detected in the low-frequency vibration spectrum of the turbocharger housing with cylindrical bearings, and the connection of the detected diagnostic features with defects in sliding bearings has been established. Blade frequencies of the compressor and turbines on turbochargers with cylindrical and elliptical sliding bearings have been found in the high-frequency part of the vibration spectrum. These frequencies are necessary for identifying rotor harmonics and bearing frequencies. It has been established that for a defect-free bearing of turbochargers with elliptical and cylindrical sliding bearings, the vibration velocity of the rotor harmonics and the bearing frequency should not exceed the rated values.  

Study on the Blasting Vibration Characteristics of Shallow Tunnel under Unsymmetrical Pressure

2012 ◽  
Vol 204-208 ◽  
pp. 1405-1408
Author(s):  
Wen Xue Gao ◽  
Xi Meng Sun ◽  
Bing Hui Hou ◽  
Ning Ning Chen
Keyword(s):  
Vibration Frequency ◽  
Resonance Effect ◽  
Low Frequency ◽  
Ground Surface ◽  
Vibration Velocity ◽  
Blasting Vibration ◽  
Tunnel Excavation ◽  
Surface Vibration ◽  
Lining Structure ◽  
Rock Tunnel

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.

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 ◽  
...  
Keyword(s):  
Vibration Frequency ◽  
Energy Input ◽  
Low Frequency ◽  
Vibration Velocity ◽  
Weak Rock ◽  
Blasting Vibration ◽  
Main Frequency ◽  
Tunnel Blasting ◽  
The Right ◽  
Rock Tunnels

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.

scholarly journals Effect of the Size and Position of a Damping Ditch on the Reduction of the Blasting Vibration

2020 ◽  
Vol 2020 ◽  
pp. 1-15
Author(s):  
Baofu Duan ◽  
Shizhan Shen ◽  
Guoshan Ta ◽  
Kebin Sun ◽  
Wei Hou ◽  
...  
Keyword(s):  
Nuclear Power ◽  
Simulation Software ◽  
Vibration Velocity ◽  
Second Phase ◽  
Blasting Vibration ◽  
Factors Affecting ◽  
Practical Applications ◽  
Vibration Data ◽  
Vibration Attenuation ◽  
Different Depths

The size and position of the damping ditch have a direct impact on the blasting vibration. In order to explore the effect of damping ditches of different sizes and positions, we investigated field blasting in the A3 area of the second phase of the Lufeng Nuclear Power Plant project. The simulation software ANSYS/LS-DYNA was used to simulate the vibration propagation of damping ditches with different depths, widths, and positions. Secondly, the vibration data of the corresponding measuring points were collected and the amplitude reduction was analyzed in different situations. An analysis of the numerical simulation results showed that an increase in the damping ditch width increased the vibration amplitude at the top of the building. The depth and position of the damping ditch were the main factors affecting the damping performance. A regression analysis was conducted using the Sadove equation for vibration velocity. It was found that the regression coefficient of the Sadove equation did not meet the required standards when a damping ditch was present. The vibration attenuation equations were fitted for the top and the base of the building. The results of this study provide reference data for the excavation and arrangement of damping ditches in practical applications.

Experimental Study on the Technology of Middle Empty Hole in Parallel Hole Cut Blasting

2012 ◽  
Vol 594-597 ◽  
pp. 1314-1317 ◽  
Author(s):  
Ren Shu Yang ◽  
Yu Long Che ◽  
Xing Tong ◽  
Yu Lin Mi ◽  
Lin Feng
Keyword(s):  
Adverse Effect ◽  
Eye Tracking ◽  
Vibration Velocity ◽  
Utilization Rate ◽  
Blasting Vibration ◽  
Test Results ◽  
Residential Areas ◽  
Blasting Excavation ◽  
Stress Concentration Effect ◽  
Parallel Hole

In order to reduce the adverse effect of the blasting vibration velocity to residents in the urban subway blasting excavation construction, and made it meet the requirements of design, based on the stress concentration effect of empty hole, carried out the research of middle empty hole in parallel hole cut blasting. Adopted the technology of middle empty hole in parallel hole cut blasting, by measuring the blasting vibration velocity, the utilization rate of borehole, the half eye tracking rate, and so on, the results showed that the blasting vibration velocity of cut blasting was 0.69cm/s, the blasting vibration of expansion slot blasting was 1.27cm/s, the borehole utilization was 90%, and the half eye tracking rate of periphery holes was 90%. The test results showed that this technology could effectively reduce the blasting vibration under the residential areas in blasting excavation, the effective experiences could be used in the similar projects.

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