scholarly journals Vibration Effect Induced by Rock Breaking Technology Based on Dry Ice and Energy-gathered Agent in Trench Excavation

2022 ◽  
Vol 2148 (1) ◽  
pp. 012023
Author(s):  
Wu Ye ◽  
Yong Lu ◽  
Lingzhi Xi ◽  
Qiang Zhang ◽  
Shaobin Hu
Keyword(s):  
Rock Breaking ◽  
Vibration Velocity ◽  
Engineering Practice ◽  
Dry Ice ◽  
Hypocentral Distance ◽  
Oil Pipeline ◽  
Vibration Effect ◽  
Velocity Waveform ◽  
Site Test ◽  
Trench Excavation

Abstract Rock breaking technology based on dry ice and energy-gathered agent has been developed and successfully applied in trench excavation for construction of oil pipeline. The vibration velocity waveform induced by this technology was monitored in site test to determine the attenuation law of vibration velocity with hypocentral distance. The results show that this rock breaking technology is effective method of trench excavation. It does not excessively damage the adjacent rock mass, ensuring the integrity of ditch walls. The vibration velocity induced by this technology is decay with the increase of hypocentral distance. At the hypocentral distance of 10m, the vibration velocity reduces to less than 20mm/s, which meets the requirements of the safety standard of blasting vibration in general buildings engineering. The results of this experiment have an important guiding effect on the field engineering practice and application of rock breaking technology based on dry ice and energy-gathered agent.

scholarly journals Experiment and Analysis of Wedge Cutting Angle on Cutting Effect

2020 ◽  
Vol 2020 ◽  
pp. 1-16
Author(s):  
Deqiang Yang ◽  
Xuguang Wang ◽  
Yinjun Wang ◽  
Huaming An ◽  
Zhen Lei
Keyword(s):  
Construction Cost ◽  
Economic Benefits ◽  
Tunneling Rate ◽  
Vibration Velocity ◽  
Utilization Rate ◽  
Engineering Practice ◽  
Blasting Vibration ◽  
Cutting Depth ◽  
Vertical Side ◽  
Cutting Angle

In the process of tunnel excavation, large charge wedge cutting blasting is widely used to improve the effect of cut blasting and speed up the excavation rate, which is tantamount to increasing the construction cost. In order to save economic cost and improve cutting blasting effect, wedge cutting models with five different cutting angles were experimented and studied by using concrete materials on the basis of similarity theory analysis. The relationships among cutting depth, blasting volume, blasting fragment, and cutting angle are studied and deduced by the dimensional analysis method. The polynomial fitting of cutting depth, blasting volume, blasting fragment, and cutting angle is carried out according to the experimental data, and the corresponding fitting formula is obtained. The optimum cutting depth, hole utilization rate, blasting volume, and blasting fragment were obtained when the wedge cutting angle was 67° under the same charge. The values were 1.665 × 10−1 m, 92.5%, 8.390 × 10−3 m3, and 49.07 mm, respectively. With the use of TC4850N type blasting vibration meter, the blasting vibrations on the wedge in four directions are tested and analyzed. The results show that when wedge cutting inclination is 65 degrees, the peak vibration velocity is the minimum and the vibration intensity of the wedge cutting inclined side is generally smaller than that of the vertical side. Considering the cutting depth, blasting volume, blasting fragment, blasting vibration hazard, drilling error, tunneling construction cost, and other factors, the 65°∼69° wedge cutting blasting in engineering practice can improve the blasting tunneling rate and increase economic benefits. The experimental results show that the blasting tunneling rate is increased and the economic benefit is increased with the minimum construction tunneling cost, which has certain engineering significance.

Fractal Characteristics of Sandstone Cutting Fracture under Mechanical Shock Loading Conditions

2012 ◽  
Vol 226-228 ◽  
pp. 1789-1794 ◽  
Author(s):  
Shu Ren Wang ◽  
Paul Hagan ◽  
Yan Cheng
Keyword(s):  
Fractal Dimension ◽  
Size Distribution ◽  
Structural Integrity ◽  
Theoretical Calculations ◽  
Mesh Size ◽  
Rock Cutting ◽  
Weight Percent ◽  
Rock Breaking ◽  
Engineering Practice ◽  
Mechanical Shock

It is the key to guide rock-breaking design and engineering practice for how to obtain a reasonable test indicator to assess the cuttability of the rock. Some sandstone samples were tested by using the linear rock cutting machine in the school of mining engineering, University of New South Wales (UNSW), Australia. The curves characteristics for the weight percent of the broken debris with the mesh size distribution were obtained through the screening statistics. Furthermore, the fractal dimension of the specimen broken debris was derived through theoretical calculations and statistical analysis. The results showed that the rock cutting fragmentation is of significant fractal features under the mechanical shock loads. The broken debris fractal dimension of the structural integrity specimens is bigger, the range of the fractal dimension is smaller and the broken debris size distribution is more even than that of the poor structural integrity specimens. The fractal dimension is the ideal test indicator to assess and analysis the rock-breaking degree.

scholarly journals Vibration Compensation of the Frequency-Scanning-Interferometry-Based Absolute Ranging System

2019 ◽  
Vol 9 (1) ◽  
pp. 147 ◽  
Author(s):  
Fu-Min Zhang ◽  
Ya-Ting Li ◽  
Hao Pan ◽  
Chun-Zhao Shi ◽  
Xing-Hua Qu
Keyword(s):  
Standard Deviation ◽  
Vibration Frequency ◽  
Phase Modulation ◽  
Vibration Velocity ◽  
Sinusoidal Vibration ◽  
Vibration Effect ◽  
Frequency Scanning ◽  
Blind Area ◽  
Frequency Scanning Interferometry ◽  
Vibration Compensation

The frequency-scanning-interferometry-based (FSI-based) absolute ranging technology is a type of ranging technology possessing a high precision and no ranging blind area, so it can be used for non-cooperative targets. However, due to a tiny movement of a target, the Doppler shift and the phase modulation are introduced into the beat signal which results in ranging accuracy decrease. In order to solve this problem, first the model of vibration effect is established, and then the beat signals of two adjacent scanning periods are processed to produce a signal that is immune to vibration. The proposed method is verified by the experiments, and the experimental results show that the effect of vibration compensation is better for the target with a lower vibration velocity and at a lower vibration frequency (lower than 6 Hz). When the target is subjected to a sinusoidal vibration with an amplitude of 10 μm at a frequency of 1 Hz, by using the proposed method the standard deviation is reduced from 775 to 12 μm. Moreover, in the natural environment, by using vibration compensation the standard deviation is reduced from 289 to 11 μm.

Experimental Study on Bit Tooth Made of Nano-Cemented Carbide Composites in Air Hammer Drilling

2011 ◽  
Vol 233-235 ◽  
pp. 2955-2961
Author(s):  
Zhi Qiang Huang ◽  
Qin Li ◽  
Wei Li ◽  
Yi Zhou ◽  
Shi Jin Peng ◽  
...  
Keyword(s):  
Experimental Study ◽  
Wear Resistance ◽  
Rock Breaking ◽  
Cemented Carbide ◽  
Nano Composites ◽  
Transgranular Fracture ◽  
New Thought ◽  
Air Hammer ◽  
Comprehensive Performance ◽  
Site Test

It is fracture, wear and abscission of bit tooth that make up of the main failure forms for the air hammer bit, which have badly restricted the further popularization and application of the air hammer drilling. The main reason is that the ordinary cemented carbide tooth is difficult to meet the complex conditions of the air the hammer drilling. Therefore, this research puts forward a new thought that we strengthen the carbide tooth by adding the nano-Al2O3into the substrate materials of WC-Co. According to the study of several formulas of nano-composites, the test of sample performance, experimental study of impact abrasive wear and microstructure, we draw some conclusions that adding amount of nano-Al2O3can refine grain, make microstructure more uniform and improve the wear resistance of composites, but also can enhance the strength of boundaries of WC-Co and transform the fracture form from the intergranular fracture to the transgranular fracture. Meanwhile, it can also improve nano-composites comprehensive performance by adding rare earth. The result for site test of bit shows that comparing with the bit equipped the original carbide teeth, the efficiency of rock breaking of the bit equipped nano-composites teeth increase by 20% and the service life increase by 80%.

Assessment Study on Impact of Pile Driving Vibration on Surrounding Houses

2012 ◽  
Vol 457-458 ◽  
pp. 325-329
Author(s):  
Luo Yi ◽  
Sen Wei Xia
Keyword(s):  
Social Problems ◽  
Ground Vibration ◽  
Engineering Practice ◽  
Pile Driving ◽  
Effective Management ◽  
Vibration Effect ◽  
Vibration Detection ◽  
Assessment Study

It’s common to see the dispute caused by pile driving construction vibration effect, which has become a concern of social problems. The paper analyzes the mechanism and law of ground vibration caused by the pile driving construction. Combined with the engineering practice, discussion about the defects in the criteria of vibration detection is presented. It is necessary to do assessment study on impact of pile driving vibration on surrounding houses. Project practice indicates that application of assessment study on impact of pile driving vibration on surrounding houses is an effective management.

Research on Punched Pile Construction–Induced Dynamic Response of Bridge Pile Foundation

2011 ◽  
Vol 243-249 ◽  
pp. 2581-2585
Author(s):  
Yan Hua She ◽  
Hua You Su ◽  
Zheng Xue Xiao
Keyword(s):  
Dynamic Response ◽  
Impact Energy ◽  
Pile Foundation ◽  
Microseismic Monitoring ◽  
Vibration Velocity ◽  
Engineering Practice ◽  
Vibration Acceleration ◽  
Testing Data ◽  
Bridge Pile Foundation ◽  
First Time

By use of the microseismic monitoring system, the dynamic response of punched pile construction of bridge pile foundation is studied and discussed for the first time. Wave data of loads acting on the construction is group-collected by means of the microseismic experiment on site. Then the waveform, vibration frequency and energy of testing data are analyzed. On the basis of the results, the weaken rules of vibration acceleration and energy are studied, and the effect of impact energy on the vibration velocity is analyzed. It shows that impact energy attenuates exponentially with the distance from the epicentre. The conclusion establishes the theoretical basis for studying the vibrant characteristic of punched pile construction, and provides valuable reference for engineering practice to take effective measures to reduce construction vibration.

Extraction of vibration waveform characteristics of dry ice powder pneumatic rock breaking using Hilbert-Huang transform

2021 ◽  
Vol 15 (1) ◽  
Author(s):  
Xiaofei Wang ◽  
Shaobin Hu ◽  
Enyuan Wang ◽  
Qiang Zhang ◽  
Bing Liu
Keyword(s):  
Rock Breaking ◽  
Dry Ice ◽  
Hilbert Huang Transform ◽  
Ice Powder

Site Test and Analysis of Vibration Attenuation Effect of Steel Spring Floating Slab Track

2014 ◽  
Vol 1065-1069 ◽  
pp. 388-392
Author(s):  
Heng Zhang ◽  
Miao Miao Huo ◽  
Lei Meng ◽  
Xiao Shi An
Keyword(s):  
Frequency Domain ◽  
Time Domain ◽  
Vertical Vibration ◽  
Vibration Acceleration ◽  
Steel Spring ◽  
Slab Track ◽  
Vibration Effect ◽  
Acceleration Level ◽  
Vibration Attenuation ◽  
Site Test

Through site test, the paper conducts site test to vertical vibration accelerations when a train passes through steel rails and tunnel walls at a steel spring floating slab track section and a general track section in the tunnel of Yizhuang Line of Beijing Metro. The paper also conducts comparative analysis of the accelerations in time domain and frequency domain. It is shown in results that the vibration acceleration level of the steel spring floating slab track in time domain is reduced by 22 dB in tunnel walls in comparison with the general track; in the frequency domain, the vibration effect is gradually increased with frequency increase and reaches the optimal effect in medium-high frequency. The maximum vibration attenuation quantity of frequency division reaches up to 40 dB; and the maximum Z weighted vibration acceleration level is reduced by 22 dB.

scholarly journals Study on Optimization of Delay Method of Wedge Cut Blasting in Tunnel

2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Wenle Gao ◽  
Zhicheng Liu ◽  
Yanping Wang ◽  
Zhenwei Yan ◽  
Zehua Zhang
Keyword(s):  
Numerical Simulation ◽  
High Speed ◽  
Vibration Reduction ◽  
Rock Breaking ◽  
Vibration Velocity ◽  
Railway Tunnel ◽  
Tunnel Blasting ◽  
Breaking Mechanism ◽  
Coupling Algorithm ◽  
Surrounding Rock Stress

Relying on the entrance section of a high-speed railway tunnel blasting project, the fluid-solid coupling algorithm based on ANSYS/LS-DYNA was used to optimize the parameters of wedge cut blasting, and the vibration could be reduced on the basis of ensuring the blasting effect. Through the combination of visual numerical simulation results and rock-breaking mechanism of wedge cut blasting, the maximum vibration velocity of different monitoring points in the model under different segmented time delay was analyzed. The results show that the best method for detonation is dividing the blastholes into three segments from upper to lower and dividing the left and right symmetrical blastholes into one segment. When the delay time is 10 ms, the average vibration reduction ratio is the best, which is reduced by 18% compared with the six-hole simultaneous blasting. In addition, the actual surrounding rock stress has a clamping effect on the cut blasting area. The wedge cut blasting footage obtained by numerical simulation was basically consistent with the field results, which proved that the model is reasonable and effective. This study intuitively and accurately demonstrated the process of cut blasting, the superposition curve of vibration velocity and the vibration reduction results under different delay times, and the effect of cut blasting. The results can be directly applied to similar projects, and the optimal blasting parameters and related issues can be solved more accurately with the help of this engineering analysis method.

Study on Vibration Effect in Deep Underground Reservoir Blasting

2014 ◽  
Vol 1065-1069 ◽  
pp. 393-396
Author(s):  
Bo Huang ◽  
Jian Guo Wang ◽  
Hong Bo Wang ◽  
Han Lu Fu ◽  
Rong Bin Zhou ◽  
...  
Keyword(s):  
Vertical Direction ◽  
Horizontal Direction ◽  
Vibration Velocity ◽  
Blasting Vibration ◽  
Wave Impact ◽  
Vibration Effect ◽  
Blasting Excavation ◽  
Underground Reservoir ◽  
Deep Underground ◽  
Peak Value

Relying on the construction of a deep underground reservoir, vibration effects of ground were studied from two aspects: the peak value of vibration velocity and the basic frequency of blasting seismic waves, and were compared with the blasting vibration effect on the flat terrain surface. Research shows that blasting seismic wave’ impact on the surrounding building is relatively small because of its high frequency for the blasting excavation of underground reservoir. The frequency distribution in vertical and horizontal direction with scaled distance is roughly the same. And the peak value of vibration velocity in vertical direction is greater than that in horizontal direction, so blasting vibration effect in vertical direction is bigger than that in horizontal direction.

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