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

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.

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 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.


2017 ◽  
Vol 2017 ◽  
pp. 1-13 ◽  
Author(s):  
XinPing Li ◽  
JunHong Huang ◽  
Yi Luo ◽  
Qian Dong ◽  
YouHua Li ◽  
...  

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.


2014 ◽  
Vol 501-504 ◽  
pp. 1846-1849
Author(s):  
Jin Kui Li ◽  
De Jun Wang ◽  
Yue Bo Fan

Mining method inevitably causes a certain degree of damage on the shaft and surrounding rock, and severe vibration can effect on the ground buildings. The Sectional blasting design was discussed on the base of stratigraphic features, field condition and the nearest distance from surrounding buildings to Cuchun Shaft of Dalian Subway 202 construction which is taken as blasting safety control distance in this paper. The control blasting technology with short footage, weak blasting was put forward to reducing blasting vibration. The ground vibration monitoring was carried through during shaft blasting. Particle vibration velocity was from 0.28 to 1.85 cm/s and main vibration frequency was from 16.97 to 42.24 Hz at different level blasting of the surrounding rock. The monitoring results show the blasting parameters and damping measures can meet requirements of Engineering and standardization of the industry. It can provide the scientific basis and technical support for subway construction damping optimization design.


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.


2019 ◽  
Vol 2019 ◽  
pp. 1-10
Author(s):  
Fei Xue ◽  
Caichu Xia ◽  
Guoliang Li ◽  
Baocheng Jin ◽  
Yongwang He ◽  
...  

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.


2011 ◽  
Vol 243-249 ◽  
pp. 5440-5443 ◽  
Author(s):  
Zhi Zheng Yin

In this paper, the blast vibration was monitored and the data from an underground engineering were analyzed. The empirical formula of the relation between the maximum vertical direction vibration velocity and the scaled explosive charge, the maximum horizontal radius direction vibration velocity and the scaled explosive charge, the maximum horizontal tangential direction vibration velocity and the scaled explosive charge were determined. According to the blasting safety regulations, the safety standard of the blasting vibration velocity is less than 7.0 cm/s. Through monitoring and inspection, the safety evaluation of the secondary lining of the highway tunnel was made. The safety evaluation of the protected highway tunnel is safety under the blasting vibration.


2020 ◽  
Vol 2020 ◽  
pp. 1-11 ◽  
Author(s):  
Feng Cao ◽  
Sheng Zhang ◽  
Tonghua Ling

Blasting-induced vibration during the excavation of transition section in a branching-out tunnel causes damage and hence affects the safety and stability of the supporting structure and surrounding rock. To examine the effects of excavation and blasting of the transition section in the posterior tunnel on the supporting structures of the anterior tunnel, the influences of the blasting-induced vibration in the posterior tunnel on the anterior tunnel were analyzed under different surrounding rock levels, excavation techniques, distances from explosive source, and net spans. This method was performed by combining numerical simulation with blasting-induced vibration monitoring according to the construction characteristics of the transition section in a branching-out tunnel of a highway. A control technique was investigated to assure the safety and stability of the anterior tunnel during the excavation and blasting of the posterior tunnel. Results demonstrate that (1) the vibration velocity peak behind the blasting excavation surface of the tunnel is higher than that in front. These results suggest paying much attention in monitoring vibration velocity within 10 m behind the excavation surface. (2) The blasting-induced vibration velocity peak on the spandrel at the side that faces the blasting in the anterior tunnel is 2.0–2.5 times than that at the side behind the blasting. Moreover, the blasting-induced vibration velocity peak on the haunch at the side that faces the blasting in the anterior tunnel is 6-7 times than that at the side behind the blasting. (3) Instead of the full-face excavation method, the use of center cross diagram (CRD) technique or side wall pilot tunnel method is suggested for the excavation of surrounding rocks of IV-level, V-level, and III-level with a net span smaller than 3 m. (4) Vibration control measures, such as double wedge-shaped cut blasting and floor blast-hole staged detonation, were adopted by designing and optimizing blasting parameters (e.g., total explosives, maximal segment explosive quantity, detonation order, and detonation interval) in posterior tunnel. According to the test, the blasting-induced vibration velocity peak, which is monitored in the anterior tunnel, can be controlled within 10 cm/s to assure the safety and stability of the supporting structure and surrounding rocks of the tunnel.


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.


2010 ◽  
Vol 163-167 ◽  
pp. 4037-4042 ◽  
Author(s):  
Chang Ping Yi ◽  
Wen Bo Lu ◽  
Ling Feng ◽  
Gang Wang

The wave function expansion method is used to analyze the interaction process of the blasting seismic wave and the adjacent circular tunnel with steel lining, the stress expression, displacement expression and vibration velocity expression of circular tunnel under the action of blasting vibration are deduced, the stress, displacement and vibration velocity distribution of surrounding rock mass and steel lining are presented under the definite condition. In terms of the stress and vibration velocity distribution and the tensile strength of the rock mass, the critical failure vibration velocity of surrounding rock mass is obtained.


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