Report No. : GEO Report No. 298
Report Title : Ground Control for EPB TBM Tunnelling (2014), 82 p.
Author : HKIE Geotechnical Division Working Group on Cavern and Tunnel Engineering and Geotechnical Engineering Office
In December 2009, the Geotechnical Engineering Office published GEO Report No. 249, "Ground Control for Slurry TBM Tunnelling". Consultation had been made widely with the tunnelling and geotechnical industries before publication. One of the most frequent comments received was the need for an equivalent set of guidelines for Earth Pressure Balance Tunnel Boring Machine (EPB TBM) tunnelling.
This report is to provide guidelines for the auditing of the design calculations and work procedures relating to ground control during EPB TBM tunnelling in Hong Kong. There have been a number of major reports on pressurised TBM tunnelling in the last ten years including BTS/ICE (2005) and publications by international and national tunnelling associations (ITA WG-14 (2007)). It is not intended to duplicate the general advice given in these documents, but to provide more specific guidelines on issues relating to ground control for EPB TBM tunnelling in Hong Kong. The focus of the report is on key issues that affect the magnitude of ground movement due to tunnelling, and therefore the potential impact on third parties.
This report should be used as a guide only. The content of this report may require further updating as more experience in EPB TBM tunnelling and performance data in local ground conditions become available. Users applying the guidance in this report should take into account the actual ground conditions, the monitoring and controls available for ground control in the TBM chosen for the project, and the specific risks that the TBM will introduce, in preparing the design calculations, risk registers and work procedures, and in planning the risk mitigation measures and contingency plans for ground control. In all cases, the risk owner and key personnel assigned to control ground risk posed by the TBM operation must be clearly identified, and experienced tunnelling and geotechnical professionals must be employed to carry out and take responsibility for the design, site supervision and risk management.