Study on Blasting Vibration Effects of Shallow Tunnel Excavation

2011 ◽  
Vol 250-253 ◽  
pp. 2366-2370 ◽  
Author(s):  
Wen Xue Gao ◽  
Wen Long Sun ◽  
Hong Liang Deng ◽  
Xi Meng Sun
Keyword(s):  
Vibration Control ◽  
Ground Surface ◽  
Rock Fragmentation ◽  
Blasting Vibration ◽  
Shallow Tunnel ◽  
Tunnel Excavation ◽  
Surface Vibration ◽  
Multi Stage ◽  
Tunnel Blasting

Based on the practice of Huolang-yu tunnel of Mixing road reconstruction, this paper studies the monitoring of ground surface vibration and the technology of controlled blasting. The results show: (1) the ground surface vibration declines from constructed position to non-excavated areas along tunnel excavation direction. (2) The vibration control of wedge cutting holes blasting is the key to reduce or eliminate shallow tunnel vibrating calamity. And the replacement of the multi-stage small wedge cutting holes to the big wedge cutting holes ameliorates blasting vibration and rock fragmentation. (3) The overall monitoring of shallow tunnel blasting vibration and the effects, and optimum of the blasting design not only reduce blasting vibration but also ensure large circulation footage.

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 Influence of Small, Clear Distance Cross-Tunnel Blasting Excavation on Existing Tunnel below

2019 ◽  
Vol 2019 ◽  
pp. 1-16 ◽  
Author(s):  
Baofu Duan ◽  
Weizeng Gong ◽  
Guoshan Ta ◽  
Xuxu Yang ◽  
Xuewei Zhang
Keyword(s):  
Cross Section ◽  
Practical Significance ◽  
Blasting Vibration ◽  
Axial Distance ◽  
Tunnel Excavation ◽  
Vibration Effect ◽  
Blasting Excavation ◽  
Tunnel Blasting ◽  
Clear Distance ◽  
The Cross

The vibration effect generated during tunnel excavation can influence or damage adjacent tunnels. Studying and controlling the blasting vibration effect has important theoretical and practical significance, especially for new tunnels. This paper takes the tunnel project of Gao Jiu Lu-Jia Hua Cross Tunnel in Chongqing as the research background and assesses the blasting vibration influence in the up-down cross-tunnel. Onsite monitoring and numerical simulation were used to analyze peak particle velocity (PPV) changes, stress distribution, and crown settlement during the excavation process of Gao Jiu Lu I Tunnel at Jia Hua Tunnel Left Line in the cross-section. Influence laws of blasting excavation in a small, clear distance cross-tunnel on an existing tunnel below were obtained. Results show that new tunnel blasting vibrations exerted the largest influence on the crown of the existing tunnel below in the cross-section. The maximum tensile stress of the secondary lining of the existing tunnel below was mainly concentrated in the crown area. The maximum compressive stress during excavation was concentrated in the crown foot, and the stress value was less than the tensile and compressive strength of the concrete. The loosening of the surrounding rock from blasting excavation of the new tunnel caused secondary settlement of the existing tunnel crown below. The cumulative settlement value at the cross-section of the two tunnels was the largest. With an increase in axial distance from the cross-section of the existing tunnel crown, the settlement value gradually declined and became stable. These research results have reference value for the construction of a small, clear distance cross-tunnel and provide theoretical guidance for similar tunnel excavation projects in the future.

Study on Vibration Laws of Ground Particles Cause by Shallow Tunnel Blasting Construction

2013 ◽  
Vol 838-841 ◽  
pp. 1420-1424
Author(s):  
Jun Tao Wang ◽  
Qing Yang ◽  
Hai Liang Wang
Keyword(s):  
Velocity Vector ◽  
Peak Velocity ◽  
Ground Vibration ◽  
Measured Data ◽  
Vibration Monitoring ◽  
Blasting Vibration ◽  
Shallow Tunnel ◽  
Working Face ◽  
Resultant Velocity ◽  
Tunnel Blasting

In order to study ground vibration laws of shallow tunnel blasting construction, so in this paper, we put Third Bid of Qingdao Metro Line 3 as the engineering background, selecting the monitoring segment blasting vibration monitoring, studying blasting vibration peak velocity. Basing on the measured data, analyzing the variation regularity resultant velocity vector peak velocity along the tunnel axis direction. The study found that resultant velocity vector peak did not occur just above the tunnel workface, but away from the working face in 1m ~ 1.5m the range. resultant velocity vector peak located in front of the workface is 1.02 to 1.45 times of resultant velocity vector peak located behind of the workface. resultant velocity vector peak located in front of the workface is 2.26 to 2.5 times of resultant velocity vector peak above the workface. resultant velocity vector peak behind the workface is 2.3 to 3 times of resultant velocity vector peak above the workface.

Attenuation Effects of Buildings Established near Sources of Ground-Surface Vibration

2001 ◽  
Vol 8 (1) ◽  
pp. 15-24
Author(s):  
Satokazu Sumitomo ◽  
Yasutoshi Kitamura
Keyword(s):  
Ground Surface ◽  
Surface Vibration

scholarly journals A Study on Dynamic Response of Tunnel Blasting Beneath Surface Buildings

2021 ◽  
Author(s):  
chen huang ◽  
youyi zhang ◽  
Jun Zhao
Keyword(s):  
Dynamic Response ◽  
Weight Bearing ◽  
Dynamic Responses ◽  
Frame Structure ◽  
Blasting Vibration ◽  
Exterior Wall ◽  
Adjacent Buildings ◽  
Propagation Law ◽  
Blasting Excavation ◽  
Tunnel Blasting

In order to study the dynamic response of adjacent buildings in the process of tunnel blasting excavation, taking Yangjia tunnel blasting through a five-story frame structure residential building as an example, the propagation law of blasting seismic wave was analyzed by using HHT method through on-site blasting monitoring. Then, the ALE algorithm in ANSYS/LS-DYNA software was used to establish a three-dimensional numerical model based on the surrounding rock-cutting section-structure coupling to study the dynamic response of adjacent buildings under the blasting vibration of tunnel. The results show that the HHT analysis method can clearly describe the energy distribution of vibration signals in the time and frequency domain. The energy carried by the blasting vibration signal is corresponding to the detonating section, and the maximum energy appears in the cutting section, which further verifying that the vibration effect caused by the cutting hole blasting is the strongest. In the process of tunnel blasting, the dynamic responses of beams, columns and exterior walls of adjacent buildings are not consistent and show different variation rules along the height direction. In addition, the stress centralization mainly occurs in the exterior wall of the building, the joint of the exterior wall and the column, the joint of the exterior wall and the beam, and the joint of the exterior wall and the floor and other non-weight bearing area, indicating that these parts are more likely to damage and crack in the process of tunnel blasting.

Research on Deformation Mechanism of Surrounding Rock during Excavation of Large-Span Shallow-Buried Double-Arch Tunnel

2013 ◽  
Vol 392 ◽  
pp. 890-894
Author(s):  
Shao Rui Sun ◽  
Ye Xu Lu ◽  
Shao Hua Zhang ◽  
Ji Min Wu
Keyword(s):  
Deformation Mechanism ◽  
Back Analysis ◽  
Ground Surface ◽  
Surrounding Rock ◽  
Tunnel Excavation ◽  
Large Span ◽  
Main Work ◽  
Time Space ◽  
Space Effect ◽  
Force Mechanism

The deformation mechanism of surrounding rock during excavation is difficult to stability evaluation for large-span shallow-buried double-arch tunnel. Take Fenghuang mountain tunnel in Suzhou city as an example, the main work and funding are as follow: The measured data in the middle of the tunnel, including settlement on the top of the tunnel and deformation between two lateral walls, were used to calculate mechanical parameters by back analysis method. The obtained parameters were used to calculate the deformation and stress of the main tunnel excavation in the different steps. The rules includes time-space effect during main tunnel excavation, force mechanism of the middle wall and settlement on the ground surface for the surrounding rock in the main tunnel. Finally, the calculated settlement and deformation were compared to the monitoring results. The safety coefficient of surrounding rock for double-arch tunnel was obtained by strength reduction theory.

scholarly journals Safety Threshold Determination for Blasting Vibration of the Lining in Existing Tunnels under Adjacent Tunnel Blasting

2019 ◽  
Vol 2019 ◽  
pp. 1-10
Author(s):  
Fei Xue ◽  
Caichu Xia ◽  
Guoliang Li ◽  
Baocheng Jin ◽  
Yongwang He ◽  
...  
Keyword(s):  
Surrounding Rock ◽  
Blasting Vibration ◽  
Vibration Data ◽  
Maximum Charge ◽  
Blasting Excavation ◽  
Tunnel Blasting ◽  
Before And After ◽  
Rock Tunnel ◽  
A Site ◽  
Site Test

The effects of tunnel blast excavation on the lining structures of adjacent tunnels are comprehensively studied for the Xinling highway tunnel project. First, the LS-DYNA software is applied to obtain the characteristics of vibration velocities and dynamic stresses at different positions of the tunnel liner. The results indicate that the maximum peak particle velocity (PPV) is located on the haunch of the lining facing the blasting source and that the PPV and peak tensile stress decrease with the increase in the surrounding rock grade. Second, a site test on blasting vibration is conducted to verify the simulation results. By using regression analysis of the measured vibration data, the calculation method of maximum charge per delay for optimizing blasting excavation under different surrounding rock grades is obtained. Finally, based on the statistical relationship between crack alteration and PPV on the lining before and after blasting, the safety thresholds of PPV for different portions of the tunnel are determined. The recommended safety threshold of PPV is 10 cm/s for intact lining and for B-grade and V-grade linings of the surrounding rock tunnel. However, if the lining crack grade falls between 1A and B, then the recommended safety thresholds of PPV for the III-grade and IV-grade surrounding rock tunnel are 5 cm/s and 6 cm/s, respectively. The threshold PPV proposed in this study has been successfully applied to restrict blast-induced damage during new tunnel excavation of the Xinling tunnel project.

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