Ground subsidence due to the backfill pressure in tunnel boring machine

• Main Authors: C.-K. Ahn, S.-W. Lee
• Format: Article
• Language: English
• Published: Copernicus Publications 2020-04-01
• Series: Proceedings of the International Association of Hydrological Sciences
• Online Access: https://www.proc-iahs.net/382/19/2020/piahs-382-19-2020.pdf

<p>In shield tunnel boring machine constructions, backfill pressure affects surface settlement and the stability of other underground structures nearby. Therefore, it is essential to pre-calculate backfill pressure in the design stage. This study examines and compares the seven internationally known backfill pressure calculation theories and calculates and analyzes the backfill pressures in six virtual ground conditions. The calculated backfill pressure increased as the ground cover increased, but the increase rate decreased. Also, this study performs a numerical analysis to identify the impact on ground settlement and tunnel crown settlement. In the end, settlement was more impacted by face pressure than backfill pressure in the unsaturated and saturated ground conditions. Also, as the ground cover increased, the impact of backfill pressure decreased, and as the applied face pressure decreased, the impact of backfill pressure increased.</p>