Abstract:

In order to control the scale of blasting in the excavation of a tunnel and mitigate the blast-caused adverse effects, especially on its neighboring tunnel, the particle velocities of the concrete lining of an excavated tunnel caused by the blasts in its adjacent operating tunnel, were analyzed in ANSYS/LS-DYNA software. The simulated results are consistent with the in-situ measurement results, and the results show that (1) the PPV in the left part of the right tunnel close to the blast source in the left tunnel is larger than that in the right part of the right tunnel away from the blast source; (2) the ratio of the PPV in the right tunnel from the left spring line to the right spring line is in a range of 1.36-5.90, and the ratio from left sidewall to the right sidewall is 1.87-5.59; (3) the region in the right tunnel against unexcavated area in the left tunnel are affected by blasting in the left tunnel more seriously than the region in the right tunnel against excavated area in the left tunnel, and the former is 1.11-2.45 times greater than the latter, with an average value 1.64. And the left part of right tunnel closed to the blasting position in the left tunnel and situated in the negative area should be paid much attention in the actual construction of tunnels.

1 Introduction

Until now, rock blasting has been dominant in hard rock tunneling (Nateghi, 2012; Yi et al., 2017). Unfortunately, tunnel blasting always causes adverse impact on its lining or the lining of another tunnel located nearby. Many linings of tunnels were damaged by blasting during their construction (NAKANO et al., 1993; Wang et al., 2004; Li et al., 2014). Therefore, vibrations induced by blast must be controlled in tunneling.

This content is only available via PDF.
You can access this article if you purchase or spend a download.