HyD's response to media enquiries on progress of Hong Kong-Zhuhai-Macao Bridge and Tuen Mun - Chek Lap Kok Link
Regarding media enquiries on the latest progress of the Hong Kong-Zhuhai-Macao Bridge (HZMB) project and Tuen Mun - Chek Lap Kok Link (TM-CLKL) project, the Highways Department (HyD) today (October 31) responded as follows:
The entire HZMB project consists of two parts: (i) the HZMB Main Bridge (i.e. a 22.9km-long bridge and 6.7km-long subsea tunnel) situated in Mainland waters which is being taken forward by the HZMB Authority; and (ii) the link roads and boundary crossing facilities responsible by the three sides. Regardless of whether it is the HZMB Main Bridge or the related projects of the three sides, challenges in the construction and in meeting the programme schedule have been encountered. With safety and quality assurance as the major premise, the HZMB Authority and the three governments have been reviewing the progress of the projects as well as overcoming the difficulties and challenges concerned.
Regarding the bridge section of the Main Bridge, the difficulties encountered under the extreme conditions in the open sea during the construction stage have been overcome. All precast bridge deck units of the bridge section were connected in end September 2016. Meanwhile, construction of the tunnel section of the Main Bridge is still on-going (the works mainly consist of placement of the outstanding sub-sea tunnel segments and its final connection). As the placement of sub-sea tunnel segments can only proceed under prerequisite wind speed and under-water current conditions, challenges include overcoming inclement weather and sedimentation of the tunnel bedding conditions. It is anticipated that construction of the HZMB Main Bridge will enter the most critical stage next year.
As for the HZMB local projects in Hong Kong (i.e. the Hong Kong Boundary Crossing Facilities (HKBCF) and the Hong Kong Link Road (HKLR)), construction workers have been working hard to overcome the construction difficulties and challenges such as the unstable supply of materials, shortage of labour, constraints in construction due to height restriction, the environmental protection requirements and the slower-than-expected consolidation rate of reclamation works. According to the latest progress, the HyD anticipates that the target of completion of essential works for commissioning of local projects by end-2017 remains unchanged. The HyD and its resident site staff have been closely monitoring the works progress of the local projects in Hong Kong and will adopt appropriate measures where necessary.
Having regard to the progress of the HZMB Main Bridge and the related projects of the three sides, the three governments of Guangdong, Hong Kong and Macau as well as the HZMB Authority have been compiling and assessing the works programme and have reported to the Inter-departmental Task Force of the HZMB, which is chaired by the National Development and Reform Commission. The Task Force attached great importance to the HZMB project and requested the three sides, with safety and quality assurance as the major premise, to overcome the difficulties and challenges concerned and to conduct a final assessment with a view to coming up with the target commissioning date of the entire HZMB project for reporting to the Central People's Government. The assessment of the works programme of the HZMB project is at a critical stage and would require confirmation by the Task Force.
The total length of TM-CLKL is about 9km. Upon completion, it will provide a strategic link connecting the North West New Territories (NWNT) with the HZMB HKBCF, North Lantau and the Hong Kong International Airport (HKIA).
The works of TM-CLKL are currently in full swing. For the Southern Connection, construction of piers for marine viaducts and land viaducts at North Lantau was mostly completed while erection of precast deck segments for the viaducts is also in progress. To cope with complex construction environment, the contractor is required to cast about 2 600 number of large size precast deck segments within a tight construction programme, and to adopt various construction plants and methods to erect these precast deck segments. Since the viaducts are spanning over Tung Chung Navigation Channel, Airport Express Line, Tung Chung Line and North Lantau Highway, the contractor shall ensure safe and proper operation of all these major navigation channel/railways/highway during the construction. As the site area is located in close proximity to HKIA, the construction works shall also be executed in compliance with the airport height restriction.
As for the sub-sea tunnel of the Northern Connection, excavation works underneath the sea bed by Tunnel Boring Machines (TBMs) are currently in progress. Upon completion, it will be the longest tunnel in Hong Kong. It is also the first time in Hong Kong to deploy a 14m large diameter TBM for tunnel excavation underneath the sea bed and the technical requirements are much higher than normal construction works. During excavation, the hardness of rock may be higher than expected, hence affecting the excavation progress. Also, high water pressure would be encountered in the course of excavation underneath the sea bed, necessitating the use of compressed air of up to 6 bar pressure for carrying out excavation works. The contractor is required to employ specialized workers having undergone training on compressed air works to carry out inspection of TBM cutter disc and maintenance works. In Tuen Mun Area 46, the erection of precast beams for construction of toll plaza deck was completed. Also, site formation, construction of piers for land viaducts and footbridge, retaining walls and vehicular underpass are in progress.
According to the original plan, the completion time of the Southern Connection will tie in with that of the HZMB Main Bridge whilst the Northern Connection is targeted for completion in end 2018. However, in view of the above technical difficulties, the construction programme is very tight. Hence, it is believed that the TM-CLKL project cannot be completed according to the above original plan. The HyD has been closely monitoring the progress of the works to overcome the technical difficulties, and will endeavor to catch up with the progress, and carry out a comprehensive review on the commissioning of TM-CLKL.
When the HZMB is commissioned, the traffic between the HKBCF and Lantau Island can route through the existing roads on the airport island. As such, although the Southern Connection of TM-CLKL could not be completed timely, the commissioning of the HZMB will not be affected.