YU J X, LIU W J, ZHANG X,et al.Blasting vibration response characteristics of tunnel support structures in horizontally layered rock masses under initial in-situ stress[J].Journal of Henan Polytechnic University(Natural Science) ,2025,44(5):100-110.

DOI:10.16186/j.cnki.1673-9787.2023070026

Received: 2023/07/16

Revised: 2024/03/08

Published:2025/07/23

Blasting vibration response characteristics of tunnel support structures in horizontally layered rock masses under initial in-situ stress

Yu Jianxin1, Liu Wenjin1, Zhang Xin2, Zhang Hao3

1.School of Civil Engineering， Henan Polytechnic University， Jiaozuo  454000， Henan， China；2.China Railway 18 Bureau Group Co.， Ltd.， Tianjin  300222， China；3.Shandong Provincial Key Laboratory of Civil Engineering Disaster Prevention and Mitigation， Shandong University of Science and Technology， Qingdao  266590， Shandong， China

Abstract: Objectives To analyze the stability of surrounding rock during tunnel blasting excavation in horizontally layered rock masses under initial in-situ stress. Methods Using LS-DYNA finite element software， numerical models were established under three different in-situ stress levels and three sets of blasting parameters. The dynamic stress distribution and vibration velocity response at typical positions of the tunnel support structures were computed and analyzed. Results The results show that during tunnel blasting excavation in horizontally layered rock masses， the peak particle velocity （PPV） of surrounding rock behind the tunnel face increases with higher in-situ stress and changes in blasthole types. For cut-hole blasting， the maximum PPV increases by 1.86 times at 10 m behind the tunnel face， and for auxiliary-hole blasting， by 1.83 times at 15 m. The PPV at the spandrel of the tunnel face under cut-hole blasting is 4.61 times higher than that of auxiliary-hole blasting and 41.17 times higher than that of peripheral-hole blasting. As the in-situ stress increases，  the difference between lateral and vertical compressive stress in various parts of the support structure also increases. At 30 MPa in-situ stress， the maximum lateral and vertical compressive stresses in the support structure reach 186.55 MPa and 176.39 MPa， respectively. Among the three blasting types， cut-hole blasting induces the highest PPV at the vault and spandrel， while peripheral-hole blasting yields the lowest. The dynamic tensile stress of anchor bolts shows a nearly linear relationship with different blasting parameters： the peak tensile stresses are 14.21 MPa for cut-hole blasting， 5.88 MPa for auxiliary-hole blasting， and 1.36 MPa for peripheral-hole blasting， displaying a decreasing trend.  Conclusions In tunnel excavation of a horizontally layered rock masses， increased in in-situ stress leads to higher peak stresses in the support structures. Among different blasting parameters， cut-hole blasting produces the strongest vibration response.

Key words:layered rock mass;tunnel blasting;in-situ stress;blasting parameters;numerical simulation