Exploration of the best time to obtain rock structure information on the palm face during tunnel construction

Rapid acquisition of rock structure information during tunnel construction is crucial for optimizing subsequent construction strategies and avoiding engineering rock disasters. In this regard, this study proposes the best time to obtain rock structure information on the tunnel face during the construction period. By summarizing relevant studies on rock information acquisition locally and abroad and combining them with the actual situation during the construction of the Lushan Tunnel, this study analyzed the factors affecting the quality of rock information acquisition during the construction period and the approximate range of the optimal timing of acquisition. We also conducted experiments on the concentration of respiratory dust and the concentration of total dust on each section of the Lushan Tunnel construction site and explored the optimal timing of acquiring rock information on the tunnel face by conducting several dust experiments at the construction site. The results showed that the best time to obtain information was before the erection of the steel arch, which was also the best time for the engineers to conduct mechanical characterization of the tunnel face and the lining inspection of the tunnel. The optimal acquisition timing identified in this study is crucial for improving the accuracy of rock information acquisition and guiding subsequent construction programs.