MULTI-MODE TBMs-STATE OF THE ART AND RECENT DEVELOPMENTS

摘要

Tunnel alignments with variable ground conditions have become commonplace challenges for many underground projects. The conditions along the course of the tunnel often range from stable rock faces to soft, water bearing soils. Standard technologies for shielded TBMs have been optimized to handle a wider range of specific ground conditions. Technical and commercial limits are often reached when variable ground conditions become too extensive. Multi-Mode or hybrid machines incorporate the possibility to operate in different modes and therefore adapt the excavation technology in the tunnel to the actual ground conditions encountered. The paper will highlight case histories and latest developments, especially the new Herrenknecht Variable Density TBM design.