Analysis of Abnormal Use of Cement Paste in Perfusion during Tunnel Construction using TBM

Abstract

During underground tunnel construction, rock burst causes substantial problems and impacts on the perfusion material use. This article explores the influences of rock burst on a construction project in a highly complex geological area in Tibet, including segment oscillation, injection port design, segments sealing, and slurry leakage, which contribute to the abnormal use of cement slurry during TBM tunneling. After comprehensively examined the reasons for the abnormal cement slurry filling during the TBM tunneling, we reach the conclusions that, in this tunnel, it is normal for the cement slurry volume to exceed its originally designed volume. The multiple factors affecting the cement slurry perfusion can be classified into three categories, including geological factors such as high ground stress, rock burst, and the complexity of the tectonic structure, human-made factors such as imperfect segment design and infusion hole design, and mechanical factors such as the reserved deformation and excavation adjustment due to rock burst. Abnormal perfusion does not result in any decreased quality in the backfill perfusion. Based on these conclusions, this paper also proposes recommendations to solve the abnormal use of the cement filling during the tunneling.