Improving Performance of Shield TBM for Subway Tunnel Passing Through Riverbed

As a technology of mechanical excavators is developed, an application of Shield TBM becomes variable and wide. As a result, shield TBM can be applied most geological conditions, such as soil condition with high water pressure, hard rock condition, and mixed condition. However, an extensive and detail geological investigation should be conducted to select most suitable equipment and cutting tools for high performance. This paper will focus on an improvement of shield performance in difficult condition by alternative plans and modifications of shield TBM.