Dynamic Analysis of Tunnel Blasting Excavation Effect on Overpass

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.

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.


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.


Author(s):  
chen huang ◽  
youyi zhang ◽  
Jun Zhao

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.


2019 ◽  
Vol 2019 ◽  
pp. 1-16 ◽  
Author(s):  
Baofu Duan ◽  
Weizeng Gong ◽  
Guoshan Ta ◽  
Xuxu Yang ◽  
Xuewei Zhang

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.


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.


Author(s):  
Severino Fonseca Silva Neto ◽  
Silvia Ramscheid Figueiredo ◽  
Marta Cecilia Tapia Reyes ◽  
Luiza de Mesquita Ortiz

This study aims to analyze the influence of the kinetic energy of the fluid adjacent to the hull of a tanker ship in its vertical vibration frequencies, comparing them with experimental measurements obtained during sea-trials. The one-dimensional modeling of ships allows the construction of simple finite element models from the structural elements of its master section, with structural and added masses, and their frequencies are verified by full-scale measurements, during the sea-trials. The numerical results of these models, with the value of the effective shear area as a fraction of the total area of the strength steel are compared to those obtained in full-scale measurements during sea trials of an oil tanker to be converted to Offshore Construction Vessel. Global vibration measurements were carried out in two of the six ships with the same hull. Accelerometers were installed in eleven strategic points of each hull. Vibration data acquisition was performed simultaneously for these locals in thirteen rotations of the main engine. The amplitude spectra of vibration velocity on the frequency range of measurements were obtained and were plotted graphs of the evolution of the main harmonics, depending on the rotation of the main engine, in order to identify four natural frequencies of the overall vibration of the hull, which were compared to the numerical model. The calculation is performed by the added mass formulations from Burrill, Todd, Kumay and Lewis/Landweber [8] curves, including in all three-dimensional effect by Townsin [17] coefficients, which is checked against the experimental results. The comparison between numerical and experimental results allows assessing the influence of the kinetic energy of the fluid surrounding the hull in the natural frequencies of vibration of the numerical model of the tanker ship and simulating their dynamic behavior after conversion in Offshore Construction Vessel.


2011 ◽  
Vol 199-200 ◽  
pp. 870-873
Author(s):  
Hai Liang Wang ◽  
Shu Cui Cong ◽  
Bi Jun Wang ◽  
Lin Sheng Liu

According to the tunnel blasting vibration test at Kiaochow bay Cross-harbor Tunnel Guide Line Project, the regulation of the tunnel vibration velocity has been studied. Based on the analytical results, this paper finds that the change regulation of vertical, horizontal radial and tangential vibration velocity as the different distances from the work face. The tunnel vibration velocity of the rear work face is greater than the unexcavated area. The peak value of the rear work face is 2-2.5 times as large as that of the front work face, vibration velocity of the front work face attenuates gently. The paper figures out the relationship between vibration velocity and distance from sensor to the work face, which can offer a reference to similar studies.


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.


2010 ◽  
Vol 163-167 ◽  
pp. 2608-2612 ◽  
Author(s):  
Hai Liang Wang ◽  
Tong Wei Gao

According to fire station of Tuandao road along to the Yunnan road tunnel of Qingdao Cross-harbor Tunnel Guide Line Project, the blasting vibration test was carried on. This building is three-storied brick-and-concrete building. Then monitoring data of particle vibration velocity was analysised and researched. The results showed that there is magnifying effect of vertical vibration velocity on the roof of the building, but its value is lesser than particle vibration velocity of the first layer. Horizontal tangential vibration velocity was existed on the central of the building. However there was no magnifying effect of horizontal radial vibration velocity. And its value is decreased rapidly from the first layer to the second layer, and then other floors basically keep steady.


2013 ◽  
Vol 353-356 ◽  
pp. 1484-1489
Author(s):  
You Mo ◽  
Bin Teng ◽  
Zu Yin Zou ◽  
Lin Li ◽  
Mei Zhong

Kinetic research of Small spacing tunnel blasting excavation is always the hot issue both at home and abroad. In this paper, the entrance section of a small spacing tunnel is chose as an example, the Explicit dynamic finite element model and the Euler method is adopted to accurately simulate the process of blasting vibration, and the peak vibration velocity response of the tunnel is gotten. Studies has shown that, the peak velocity is more sensitive to space change when clear distance is less than 1.5 times of the hole diameter; various depth of tunnel causes different clamping action of surrounding rock, thus has different effects on peak velocity; vibration velocity at head-burst side is 5-8 times more than that at back side, vibration velocity at tunnel waist is 1.98-2.23 times more than that at up side, vibration velocity at tunnel shoulder is 1.68-1.85 times more than that at up side, so the waist position at head-burst side should be given exclusive attention.


Sign in / Sign up

Export Citation Format

Share Document