Event archive

Event Organiser: ICE

New advances in civil engineering – New developments in Tunneling Works in Hong Kong

  • Lecture
  • Hong Kong
  • 27 September 2017
  • 19:00 - 20:30
New advances in civil engineering – New developments in Tunneling Works in Hong Kong

About this event

Large span mined tunnels in soft ground: support design, instrumentation and observational approach:

The northern 200m of the Liantang Lung Shan road tunnels in Hong Kong comprises large span mined tunnels excavated through poor ground with low cover. Conventional staged tunnel excavation techniques, with heading (160m2) and bench (115m2), were adopted. An instrumented observational approach was developed to verify an optimised temporary support system for these challenging ground conditions.

Ribs were instrumented and limit settlement and load values defined which, if respected, allowed the omission of top heading invert beam and increased bench advance lengths equating to a more efficient construction progress. This comprehensive monitoring scheme enhanced control and safety of the works allowing a clearer understanding of load evolution through the various stages. A comparison of the initial and optimised design together with the monitoring measures implemented will be presented.

Pilot TBM tunnel enlargement:

Due to a tight 350m horizontal curve, the northern 500m of the Liantang Lung Shan road tunnels comprise mined tunnels of larger span (3m wider than the standard two lanes 14m TBM diameter bored tunnel), in order to provide sufficient visibility to the road users.

For programme reasons it was not possible to wait for the 500m long mined tunnel to be completed before the 14m diameter TBM was launched in the southbound tunnel to bore the 2,400m long segmental lining tunnel towards the mid-ventilation junction cavern.

As a consequence the TBM was launched within the horizontal curve, at 200m from the North Portal, and the 300m long 14m diameter TBM "pilot" tunnel within the curve subsequently had to be enlarged using mined tunneling technique to its final shape.

A 320m long temporary steel gallery was installed within the 14m diameter segmental lining tunnel, allowing the TBM logistics & continuous segments feeding through the gallery, while the tunnel enlargement of the top heading could carry on from the top of the gallery.

The concrete segments were broken ring by ring and a special impact gantry tool was used to control the segments fall onto the steel gallery. Further enlargement excavation and temporary supports installation were done, following various designs according to the variable ground conditions encountered. The enlargement of the bench was carried out in sequence with the dismantling of the temporary gallery and the TBM logistics equipment rearrangement.

Capacity: 120pax
Free of charge


*Priority will be given to ICE members.
*ICE will send confirmation e-mail to successful applicants.

Event venue

CityU SCOPE Admiralty Learning Centre
8/F United Centre
95 Queensway
Hong Kong
Hong Kong

For more information please contact:

Crystal Fung

e: crystal.fung@icehk.org.hk