The Highways Department (HyD) said today (May 18) that the last unit of the tunnel box segment in the Scenic Hill Tunnel section of the Hong Kong-Zhuhai-Macao Bridge (HZMB) Hong Kong Link Road (HKLR), weighing about 5 000 tonnes (equivalent to the total weight of 27 Boeing 747 jumbo jets), was jacked into its final position underneath the Airport Express Line (AEL) on Tuesday (May 16), with all the tunnel excavation works completed. Together with the completion of the connection of the HKLR viaduct section in March this year, the 12 kilometre-long HKLR is now completely connected, signifying the achievement of a key milestone of the HZMB Hong Kong projects and reaching readiness for commissioning by end of this year.

     The Secretary for Transport and Housing, Professor Anthony Cheung Bing-leung, visited the site today to give his encouragement to the project team and frontline workers. He said that this resounding success was indeed a hard-earned achievement, the result of the concerted efforts and continuous hard work by the project team in overcoming various difficulties and challenges since the commencement of the HKLR project in mid-2012.

     Professor Cheung was briefed by the Director of Highways, Mr Daniel Chung, on the construction of the Scenic Hill Tunnel, which involved four different construction methods to overcome the different geological and site constraints. These were the drill and blast method through Scenic Hill, the mined tunnel method underneath the Airport Road section, the cut and cover method at the reclamation area, and the box-jacking method of the tunnel box segment underneath the AEL.

     The most complex and arduous work among the tunnel works was the box-jacking operation carried out underneath the AEL. It was the first time that this method was adopted for constructing vehicular tunnels in Hong Kong. In order to reduce the impact on the AEL, the ground underneath the AEL had to be strengthened for one year before the jacking works. The tunnel box segments were cast within the deep and narrow shaft first, followed by excavating the ground at the leading face of the box segments, which were then pushed forward one by one using hydraulic jacks along the tunnel alignment. This jacking operation required a precision computerised system to synchronise the movements of all the hydraulic jacks in pushing the gigantic box segments, with very stringent technical requirements. With the unremitting efforts of the project team, this tunnel section was successfully broken through.

     The stringent airport height restrictions, due to the close proximity of the viaduct to the Hong Kong International Airport, brought a lot of challenges to the viaduct construction. For instance, construction works of the viaduct section along the Airport Channel adjacent to the South Runway had to be carried out at nighttime when the runway was closed.

     The HKLR is a dual three-lane highway about 12km long connecting the HZMB Main Bridge in the Mainland and the Hong Kong Boundary Crossing Facilities (HKBCF). It comprises (i) about 9.4km of land and marine viaduct; (ii) about 1km of tunnel through Scenic Hill; and (iii) about 1.6km of at-grade roads at the reclamation area along the east coast of the airport.

     In the meantime, the road surfacing works and installation of associated road facilities for the HKLR are being completed successively as planned. Concurrently, the HKBCF facilities (including the passenger clearance building, ancillary buildings, bridges, vehicle clearance plaza and associated facilities) are also being carried out at full swing. In accordance with the current works progress, the HyD is confident that the HZMB Hong Kong projects could be completed by the end of 2017 and achieve readiness for commissioning.

Ends/Thursday, May 18, 2017
Issued at HKT 17:35

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