Abstract
This paper presents result of analysis for operation of TBM made from the monitoring records obtained during the excavation for the DTSS in Singapore. The long distance and deep tunnel excavation of 7.3km was carried out for this project. The subsoil at the excavation depth of TBM is generally Old Alluvium underlying a relatively thin fill layer for 85% of whole distance. There were some exceptions where relatively thick layer of Kallang formation is lying at 15% at last excavation area. Tunneling was done totally within the Old Alluvium. However TBM were encountered five incidents. Four cases are caused by abrasion and operation. One case was caused by the unforeseen geological condition. According to the result of analysis for TBM operation data, added soil investigations help the understanding of geological conditions in detail and reducing risks for tunneling collapse with ground settlement.
