University of Oulu

Zhang, Q., Zhang, Z., Wu, C., Yang, J., & Wang, Z. (2022). Characteristics of vibration waves measured in concrete lining of excavated tunnel during blasting in adjacent tunnel. Coatings, 12(7), 954. https://doi.org/10.3390/coatings12070954

Characteristics of vibration waves measured in concrete lining of excavated tunnel during blasting in adjacent tunnel

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Author: Zhang, Qingbin1,2; Zhang, Zongxian2; Wu, Congshi1;
Organizations: 1School of Civil Engineering, Changsha University of Science & Technology, Changsha 410014, China
2Oulu Mining School, University of Oulu, 90014 Oulu, Finland
3School of Civil Engineering, Central South University, Changsha 410075, China
Format: article
Version: published version
Access: open
Online Access: PDF Full Text (PDF, 3.7 MB)
Persistent link: http://urn.fi/urn:nbn:fi-fe2023021427232
Language: English
Published: Multidisciplinary Digital Publishing Institute, 2022
Publish Date: 2023-02-14
Description:

Abstract

The effect of a blasting vibration from an excavating tunnel on an adjacent excavated tunnel is of great importance for the stability and security of twin tunnels. Due to the relatively small distance between the tunnel face of the excavating tunnel and the concrete lining of the excavated tunnel, the impact of blasting could be significant and should be considered in a practical project. In order to control the blasting scales during the excavation of one tunnel and minimize the effect of blasting on the adjacent one, research based on field-blasting tests performed on twin tunnels is presented in this study. The particle velocities on the concrete lining of the excavating tunnel caused by blasting from the adjacent excavated tunnel were measured and analysed during six rounds of blasts. According to the measured vibration waves, it was clear that the peak particle velocity (PPV) from each blast was always induced by cut blasting, therefore, the maximum vibration due to each blast was mainly dependent on cut blasting. The measured maximum PPV for all the blasts was 15.55 cm/s, corresponding to a maximum tensile stress of 1.44 MPa observed on the concrete lining, which was smaller than the tensile strength of the concrete lining, in accordance with the one-dimensional elastic-wave theory. Moreover, the attenuation of the vibration waves varied in different regions, and they could be utilized to demonstrate the impact characteristics of the blasting; e.g., the particle velocities in the region along the excavating direction were 1.12 to 1.79 times larger than those in the region opposite to the excavating direction, and the difference increased with the increasing distance to the blasting source. The particle velocities on the side of the excavated tunnel close to the excavating tunnel were larger than those on the other side of the excavated tunnel. However, the particle velocities of the two aforementioned regions were similar when the distance between the measuring point and the blasting source was more than 6 m in the longitudinal direction of the tunnels. Furthermore, the measured vibration waves could be used to evaluate and improve the blast designs of tunnelling with the drill-and-blast method.

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Series: Coatings
ISSN: 2079-6412
ISSN-E: 2079-6412
ISSN-L: 2079-6412
Volume: 12
Issue: 7
Article number: 954
DOI: 10.3390/coatings12070954
OADOI: https://oadoi.org/10.3390/coatings12070954
Type of Publication: A1 Journal article – refereed
Field of Science: 216 Materials engineering
Subjects:
Funding: This work was supported by the National Nature Science Foundation of China (Grant Nos. 51508038, 51274049 and 51908065) and the Key Disciplines Research Funds for the Changsha University of Science and Technology (Grant No. 13ZDXK11).
Copyright information: © 2022 by the authors. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).
  https://creativecommons.org/licenses/by/4.0/