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.

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.

Safety Control of Blasting Construction in New Austrian Metro Tunnel

2012 ◽  
Vol 446-449 ◽  
pp. 2462-2465 ◽  
Author(s):  
Hong De Wang ◽  
Xiu Feng Shen
Keyword(s):  
Regression Analysis ◽  
Vibration Monitoring ◽  
Actual Condition ◽  
Vibration Velocity ◽  
Charge Weight ◽  
Blasting Vibration ◽  
Safety Control ◽  
Blasting Excavation ◽  
Tunnel Blasting ◽  
Metro Tunnel

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.

Dynamic Analysis of Tunnel Blasting Excavation Effect on Overpass

2014 ◽  
Vol 971-973 ◽  
pp. 992-996
Author(s):  
Chun Lei Xin ◽  
Bo Gao
Keyword(s):  
Three Dimensional ◽  
Simulation Method ◽  
Vertical Vibration ◽  
Vibration Velocity ◽  
Blasting Vibration ◽  
Strong Constraint ◽  
Protection Measures ◽  
Blasting Excavation ◽  
Tunnel Blasting ◽  
Complicated Conditions

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.

scholarly journals Numerical Analysis of the Influence of Foundation Pit Blasting on a Nearby Metro Tunnel

2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Haibo Wang ◽  
Yaoyao Wang ◽  
Mengxiang Wang ◽  
Qi Zong
Keyword(s):  
Dynamic Load ◽  
Horizontal Displacement ◽  
Vibration Velocity ◽  
Blasting Vibration ◽  
Lagrangian Analysis ◽  
Deep Foundation ◽  
Foundation Pit ◽  
Blasting Excavation ◽  
Metro Tunnel ◽  
City Construction

It is important to guarantee the safety of adjacent underground structures during the foundation pit blasting excavation of modern city construction. The blasting excavation construction of a large, deep foundation pit near an existing metro station of Guangzhou Metro Line 3 is used as the example in this study. Based on blasting vibration field test results, the influence of blasting dynamic load on the lining of an adjacent metro tunnel is numerically analyzed in simulation using Fast Lagrangian Analysis of Continua 3D (FLAC3D), and the relationships between the blasting vibration velocity and stress and the displacement of the metro tunnel lining are obtained. The results show that the stress of lining structure is within the allowable range under the experimental blasting conditions, the lining displacement increases linearly with the applied dynamic vibration velocity, and the vertical displacement of the lining is more obviously affected than the horizontal displacement by the dynamic load. This study can be used as a basis for the control of blasting vibration in a complex urban environment. Its practical application shows that the proposed blasting plan and parameters are reasonable and effective.

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.

scholarly journals Influence of Blasting Vibration on Young Concrete Bridge: A Case Study of Yesanhe Super Large Bridge

2017 ◽  
Vol 2017 ◽  
pp. 1-13
Author(s):  
Ming Chen ◽  
Jun Zhang ◽  
Wenbo Lu ◽  
Peng Yan ◽  
Ke Deng
Keyword(s):  
Numerical Simulation ◽  
Vertical Direction ◽  
Vibration Velocity ◽  
Blasting Vibration ◽  
Box Girder ◽  
Blasting Excavation ◽  
Young Concrete ◽  
Compressive Strength Of Concrete ◽  
The Impact

Influence of blasting vibration on young concrete structure is an important issue in the field of hydropower engineering, transportation, and so forth. Based on influence of blasting excavation on concrete pouring progress of box girder in nearby Yesanhe Super Large Bridge, which is located in Hubei Province of China, a method combining field test and numerical simulation is used to study influence of blasting vibration on young concrete super large bridge. The results show that blasting excavation of nearby Yesanhe Hydropower Station induced vibration response on Yesanhe Bridge and peak particle velocity (PPV) on the bridge was quite small under test conditions. Monitoring data and numerical simulation both indicate that PPV of box girder is 1 to 4 times larger than that of pier foundation; with the extension of bridge cantilever casting section, velocity amplification factors of different parts of the box girder have different changes and duration of vibration in vertical direction increases. Three days after concrete pouring, the impact of concrete ageing on PPV and damage distribution of the bridge is not obvious. When vibration velocity of pier foundation is within 2 cm/s, the maximum tensile and compressive stress of box girder concrete are less than the tensile and compressive strength of concrete, so that blasting vibration unlikely gives impact on the safety of bridge.

scholarly journals Mechanism Study on Elevation Effect of Blast Wave Propagation in High Side Wall of Deep Underground Powerhouse

2018 ◽  
Vol 2018 ◽  
pp. 1-15 ◽  
Author(s):  
Xinping Li ◽  
Junlin Lv ◽  
Yi Luo ◽  
Tingting Liu
Keyword(s):  
Side Wall ◽  
Calculation Model ◽  
Vibration Velocity ◽  
Blasting Vibration ◽  
Underground Powerhouse ◽  
High Side ◽  
Site Monitoring ◽  
Fluctuation Phenomenon ◽  
Blasting Excavation ◽  
Elevation Effect

In view of the influence of blasting excavation in the deep burial underground powerhouse on the dynamic disturbance and blasting vibration of side wall and surrounding rock, the blasting vibration test method is often used for on-site monitoring and control. Taking the blasting excavation of the high side wall of an underground powerhouse of a hydropower station as the engineering background, a long-term blasting vibration test is carried out on the site. The measuring points are arranged along the elevation direction and horizontal direction of the high side wall of the powerhouse. Through analyzing and comparing the blasting vibration velocity values extracted from a large number of on-site measured data in the elevation direction, an interesting phenomenon is found. The measured vibration velocity of the rock anchor beam in the area far away from the blasting is greater than that in the area near the blasting, and the vibration velocity after the casting of the rock anchor beam is greater than that before the casting. In order to avoid the randomness and contingency of the measured data, based on the blasting parameters, loading quantity, and rock mechanical characteristics used in the field, the elevation effect of the numerical model of the underground powerhouse is established by using the dynamic finite element software. By comparing the numerical simulation and the on-site monitoring of the elevation direction vibration velocity at the same location, it is found that the two have the same law, which verifies the reliability of the numerical calculation model. By changing the elevation and horizontal distances to select the measuring points in the numerical model, the propagation curve of the blasting vibration of the high side wall of the underground powerhouse in the elevation direction is obtained and the wave propagation phenomenon and the local elevation amplification effect of blasting vibration velocity in the side wall of the powerhouse are found. By means of changing the morphology characteristics of the rock anchor beam, a numerical calculation model of the rock anchor beam before casting is established, and the blasting vibration velocity in the elevation direction of the same measuring point as the original model is extracted. The analysis and comparison results show that the “whiplash effects” caused by the reflection superposition of the convex morphology characteristics of the rock anchor beam on the blast wave and the vibration response of the rock mass at the step part is the main factor for the elevation effect. The fluctuation phenomenon of the vibration velocity in the elevation direction is caused by the natural frequency and the main vibration mode of the high side walls, and the reflection superposition of the convex geomorphology characteristics of the rock anchor beam will aggravate this fluctuation phenomenon. Therefore, in the construction of deep underground powerhouses, attention should be paid to the blasting construction and support design of the rock anchor beam.

scholarly journals Numerical Simulation of Blast Vibration and Crack Forming Effect of Rock-Anchored Beam Excavation in Deep Underground Caverns

2017 ◽  
Vol 2017 ◽  
pp. 1-13 ◽  
Author(s):  
XinPing Li ◽  
JunHong Huang ◽  
Yi Luo ◽  
Qian Dong ◽  
YouHua Li ◽  
...  
Keyword(s):  
Rock Mass ◽  
In Situ Stress ◽  
Surrounding Rock ◽  
Vibration Velocity ◽  
Blasting Vibration ◽  
Finite Element Software ◽  
Underground Cavern ◽  
Underground Caverns ◽  
Blasting Excavation

Aiming at surrounding rock damage induced by dynamic disturbance from blasting excavation of rock-anchored beam in rock mass at moderate or far distance in underground cavern, numerical model of different linear charging density and crustal stress in underground cavern is established by adopting dynamic finite element software based on borehole layout, charging, and rock parameter of the actual situation of a certain hydropower station. Through comparison in vibration velocity, contour surface of rock mass excavation, and the crushing extent of excavated rock mass between calculation result and field monitoring, optimum linear charging density of blast hole is determined. Studies are also conducted on rock mass vibration in moderate or far distance to blasting source, the damage of surrounding rock in near-field to blasting source, and crushing degree of excavated rock mass under various in situ stress conditions. Results indicate that, within certain range of in situ stress, the blasting vibration is independent of in situ stress, while when in situ stress is increasing above certain value, the blasting vibration velocity will be increasing and the damage of surrounding rock and the crushing degree of excavated rock mass will be decreasing.

scholarly journals Prediction of Bench Blasting Vibration on Slope and Safety Threshold of Blasting Vibration Velocity to Undercrossing Tunnel

2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Li He ◽  
Dongwang Zhong ◽  
Yihe Liu ◽  
Kun Song
Keyword(s):  
Element Model ◽  
Surrounding Rock ◽  
Vibration Monitoring ◽  
Vibration Velocity ◽  
Blasting Vibration ◽  
Slope Surface ◽  
Safety Criterion ◽  
Construction Period ◽  
Blasting Excavation ◽  
Blasting Load

The reconstruction and expansion project of oil reserve base often faces the excavation and blasting of the slope and undercrossing tunnel at the same time. Due to the flammable and explosive liquid storage nearby, the tight construction period, and the high requirements of collaborative construction, once the blasting accident occurs, the consequences are unimaginable. To facilitate safe and timely cooperative blasting construction of the slope and undercrossing tunnel, a vibration monitoring test of the slope and tunnel surrounding rock is conducted. The vibration response characteristics of the rock surrounding the slope and tunnel are analyzed, and a mathematical prediction model for the peak particle velocity (PPV) with consideration of the influence of the relative slope gradient (H/D) is established based on dimension analysis theory, which improves the prediction accuracy of PPV at the slope surface. ANSYS/LS-DYNA is used to establish a 3D finite element model for the slope and tunnel, and the dynamic response of the tunnel surrounding rock under blasting load is verified through field monitoring data. A linear statistical relationship between PPV and effective tensile stress (ETS) of the tunnel surrounding rock is established. The PPV safety criterion of the tunnel surrounding rock under blasting load is proposed to be 10 cm/s according to the first strength theory, and hence, the minimum safety distance from the tunnel working face to the slope surface is calculated to be 36 m. Finally, the excavation timing arrangement of the slope and tunnel is proposed, which has been successfully applied to the expansion project, and the construction period has been effectively shortened by 45 days while ensuring construction safety. The research results have great guiding significance to similar cooperative blasting excavation engineering for high slope and adjacent tunnel with safety and efficiency.

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.

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