Numerical Study on the Mechanism and Application of Artificial Free Surfaces in Bedrock Blasting of Shield Tunnels
During the pretreatment construction of blasting in shield tunnel bedrock, in order to reduce the impact of blasting vibration on the surrounding environment and improve the effect of rock blasting, the method of creating an artificial free surface is proposed. From the point of creating an artifici...
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| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
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Wiley
2021-01-01
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| Series: | Geofluids |
| Online Access: | http://dx.doi.org/10.1155/2021/9988120 |
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| author | Yanjun Qi Linming Dou Zhaoxing Dong Zheng Jiang Bo Meng Junzhong Zhang |
| author_facet | Yanjun Qi Linming Dou Zhaoxing Dong Zheng Jiang Bo Meng Junzhong Zhang |
| author_sort | Yanjun Qi |
| collection | DOAJ |
| description | During the pretreatment construction of blasting in shield tunnel bedrock, in order to reduce the impact of blasting vibration on the surrounding environment and improve the effect of rock blasting, the method of creating an artificial free surface is proposed. From the point of creating an artificial free surface, this paper numerically studies the function mechanism and parameter optimization of artificial free faces in shield tunnel bedrock blasting construction. The propagation characteristics of explosion stress waves at the interface between the rock and the artificial free face and the effect of the artificial free face on the shield tunnel bedrock blasting were analyzed. The results indicate that, as the explosion stress wave transmits to the artificial free face, a part of the stress wave is reflected back to the bedrock, increasing the energy in the bedrock that needs blasting and improving the blasting effect and utilization rate of the blasting energy. The reduction degree of the peak velocity of the surface particle is more than 50%, and the reduction degree of the peak velocity of the particle near the artificial free face is more than 77%. The existence of the artificial free face reflects the stress wave and superimposes with the original stress waves, increasing the effective stress in the blasting area, and the effective stress can be increased by 5 MPa or more. The peak vibration velocity of the surface particle decreases with an increasing diameter of the empty holes and the distance between the empty holes and the blasting holes. The parameter design value of the artificial free face is put forward: the diameter of the hole is 200 mm, the distance between the empty holes and the center of the blasting holes is 60 cm, and the depth of the empty hole is the same as the blasting hole. |
| format | Article |
| id | doaj-art-8a89e8208aee4f378a9448ef41b2d84c |
| institution | Kabale University |
| issn | 1468-8115 1468-8123 |
| language | English |
| publishDate | 2021-01-01 |
| publisher | Wiley |
| record_format | Article |
| series | Geofluids |
| spelling | doaj-art-8a89e8208aee4f378a9448ef41b2d84c2025-08-20T03:37:51ZengWileyGeofluids1468-81151468-81232021-01-01202110.1155/2021/99881209988120Numerical Study on the Mechanism and Application of Artificial Free Surfaces in Bedrock Blasting of Shield TunnelsYanjun Qi0Linming Dou1Zhaoxing Dong2Zheng Jiang3Bo Meng4Junzhong Zhang5School of Mechanics and Civil Engineering, China University of Mining and Technology, Xuzhou 221116, ChinaState Key Laboratory of Coal Resources and Safe Mining, China University of Mining and Technology, Xuzhou 221116, ChinaSchool of Mechanics and Civil Engineering, China University of Mining and Technology, Xuzhou 221116, ChinaSchool of Mechanics and Civil Engineering, China University of Mining and Technology, Xuzhou 221116, ChinaSchool of Mechanics and Civil Engineering, China University of Mining and Technology, Xuzhou 221116, ChinaSchool of Mechanics and Civil Engineering, China University of Mining and Technology, Xuzhou 221116, ChinaDuring the pretreatment construction of blasting in shield tunnel bedrock, in order to reduce the impact of blasting vibration on the surrounding environment and improve the effect of rock blasting, the method of creating an artificial free surface is proposed. From the point of creating an artificial free surface, this paper numerically studies the function mechanism and parameter optimization of artificial free faces in shield tunnel bedrock blasting construction. The propagation characteristics of explosion stress waves at the interface between the rock and the artificial free face and the effect of the artificial free face on the shield tunnel bedrock blasting were analyzed. The results indicate that, as the explosion stress wave transmits to the artificial free face, a part of the stress wave is reflected back to the bedrock, increasing the energy in the bedrock that needs blasting and improving the blasting effect and utilization rate of the blasting energy. The reduction degree of the peak velocity of the surface particle is more than 50%, and the reduction degree of the peak velocity of the particle near the artificial free face is more than 77%. The existence of the artificial free face reflects the stress wave and superimposes with the original stress waves, increasing the effective stress in the blasting area, and the effective stress can be increased by 5 MPa or more. The peak vibration velocity of the surface particle decreases with an increasing diameter of the empty holes and the distance between the empty holes and the blasting holes. The parameter design value of the artificial free face is put forward: the diameter of the hole is 200 mm, the distance between the empty holes and the center of the blasting holes is 60 cm, and the depth of the empty hole is the same as the blasting hole.http://dx.doi.org/10.1155/2021/9988120 |
| spellingShingle | Yanjun Qi Linming Dou Zhaoxing Dong Zheng Jiang Bo Meng Junzhong Zhang Numerical Study on the Mechanism and Application of Artificial Free Surfaces in Bedrock Blasting of Shield Tunnels Geofluids |
| title | Numerical Study on the Mechanism and Application of Artificial Free Surfaces in Bedrock Blasting of Shield Tunnels |
| title_full | Numerical Study on the Mechanism and Application of Artificial Free Surfaces in Bedrock Blasting of Shield Tunnels |
| title_fullStr | Numerical Study on the Mechanism and Application of Artificial Free Surfaces in Bedrock Blasting of Shield Tunnels |
| title_full_unstemmed | Numerical Study on the Mechanism and Application of Artificial Free Surfaces in Bedrock Blasting of Shield Tunnels |
| title_short | Numerical Study on the Mechanism and Application of Artificial Free Surfaces in Bedrock Blasting of Shield Tunnels |
| title_sort | numerical study on the mechanism and application of artificial free surfaces in bedrock blasting of shield tunnels |
| url | http://dx.doi.org/10.1155/2021/9988120 |
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