Effect of Blasting During Tunnel Excavation on an Existing Adjacent Tunnel

Abstract

In recent decades, the effects of blast loads on existing structures have gained considerable attention due to the increase in threat from various activities. Site-specific empirical relationships for calculation of blast-induced vibration parameters like Peak Particle Velocity (PPV), Peak Particle Acceleration (PPA), and Peak Particle Displacement (PPD) are commonly used for the estimation of the impact of blasting vibration on an existing adjacent tunnel. However, these relationships are not able to consider the variation in rock parameters and uncertainty of in situ conditions such as modern rock mass classifications (i.e., RMR, Q-system, RQD). In this paper, a published blast data of various researchers in different rock sites at Croix-Rousse tunnel in France have been collected and used to propose a generalized regression model for PPV by considering the effects of rock parameters like Rock Mass Rating (RMR) system, damping ratio "", Dynamic Young's modulus "E d ". By using the numerical analysis method, the proposed regression model of PPV (Empirical Formula) function of a variable and multivariate can be directly used in the prediction of blast-induced vibrations in rocks.

Optimization of Blasting Parameters Considering Both Vibration Reduction and Profile Control: A Case Study in a Mountain Hard Rock Tunnel

“…Some of the literature shows that PPV changes with detonation distance and charge amount, but this trend is not obvious from the analysis of collected blasting vibration data. This is due to uncontrollable factors such as the complexity of geological conditions [11,50]. Although the acquisition of monitoring data is performed in the excavation section with similar geological conditions, it is still affected by other uncontrollable variables.…”

“…Xia et al [10] took the Damaoshan Highway tunnel project as an example to comprehensively study the impact of tunnel blasting excavation on the surrounding rock and lining system of adjacent tunnels and proposed a tunnel damage control method based on PPV threshold control via on-site experiments. Van Kien Dang et al [11] argue that the empirical formula derived from singleparameter Peak Particle Velocity (PPV) does not take into account the changes between rock parameters and in situ conditional parameters. Therefore, rock parameters such as the Rock Mass Rating (RMR) and dynamic Young's modulus are introduced into the establishment of a multivariable PPV generalized regression model.…”