By Miss S S TO 
On 27 August 2005, the CV Division organised a technical visit to the Route 8 Stonecutters Bridge Project with 28 members attended.

The visit started with an introduction by Mr Bob Lind, the PRE of Ove Arup & Partners Hong Kong Ltd (OAP). He outlined the scope of work, and we toured the construction site at Container Terminal 8 with pile foundation and temporary work for span erection.

This new bridge provides access between Container Terminal 8 (CT8) and Container Terminal 9 (CT9), which forms part of a new east-west route linking the eastern part of the New Territories to the Airport on Lantau Island. The bridge has a clear span of 1,018 m with back spans of 289 m each located at the backup land of CT8 on Stonecutters Island and of CT9 on Tsing Yi Island.

Bored pile is adopted as the foundation scheme with diameter of 2 m to 2.8 m. Pre-drilling works started in the early stage of construction to investigate and confirm the founding stratum. From pre-drilling, rock stratum was found at around -50 mPDat CT8 and varies from -50 mPD to -80 mPD at CT9. Fault zones were also discovered during pre-drilling. Re-design of pile foundation was required.

This cable-stayed bridge is a concrete and steel composite structure. It has a steel deck main span with the concrete deck back spans. For the tower, the concrete part is erected to +175 mPD, and the steel part which is made by carbon steel and stainless steel is erected from +175 mPD to +293 mPD. 

Wind tunnel tests were carried out to verify the bridge wind loading and aeroelastic stability during construction. All temporary structures and erected equipment would be presented in the models with and without temporary measures added to damp undesired wind effects. Both section and full aeroelastic bridge model testing were undertaken.

Concrete back span will be erected approximately 70 m from ground level. Grade 40/20D concrete falsework with temporary pile foundation together with steel braces instead of typical steel falsework is used. This method is found to be more economical when compared with the traditional method in this project. Concrete falsework will finally be removed upon the deck erection completion and it may be reused for environmental purpose.

The visit was successful and valuable. On behalf of the CV Division and all participating members, we would like to thank Mr Bob Lind, Mr Wing Luk and their colleagues for kind arrangement and informative visit.