Web care text

About HZMB

Project Uniqueness

Hong Kong – Zhuhai – Macao Bridge

The Hong Kong – Zhuhai – Macao Bridge (HZMB), straddled across Lingdingyang of Pearl River Estuary, linking the Hong Kong Special Administrative Region (HKSAR), Zhuhai City of Guangdong Province and Macao Special Administrative Region. The total length is about 42km, counting from the Hong Kong Boundary Crossing Facilities at the east to the Zhuhai/Macao Boundary Crossing Facilities at the west. The uniqueness of the project includes:

 

  1. The HZMB will be the longest bridge-cum-tunnel sea-crossing with dual 3-lane carriageway, which is about 35.6km in length from the shore of northern Lantau to the western shore of Pearl River Estuary.

  2. The HZMB is to be built with 120 years design life. The design and construction standard not only need to satisfy the requirements stated in Mainland's relevant regulations and the feasibility study report, but also suitably taking into account Hong Kong and Macao Standards.

  3. The HZMB construction environment is complicated. Frequent typhoons, crisscross navigation, airport height restrictions, high environmental standards, etc should be taken into considerations.

  4. To minimize the impact of the bridge design to river flow, navigation and hydrology, there is stringent requirement to control the water blockage ratio during the selection of options.


Using Large Span Sea Viaduct

Using Large Span Sea Viaduct

The western sea viaduct will be composed of long span bridge sections with main spans in the range of 75-180m. It passes over a navigation channel with a clearance of 41m. Turnaround facility will be provided on this dual 3-lane highway for emergency and operational usages.

Adopting Specific Measures to Minimize Impacts to the Natural Environment

Adopting Specific Measures to Minimize Impacts to the Natural Environment

To the east of the sea viaduct section, the HKLR runs into the Airport Channel between the Hong Kong International Airport and the North Lantau. Several measures of the HKLR have been adopted to minimize disturbance to the existing natural environment. These include spanning over the headland between San Shek Wan and Sha Lo Wan of Lantau Island by adopting longer span lengths without physical contact with Lantau Island, minimizing the number of piers of viaduct portion at Sha Lo Wan to reduce visual impact, burying pile caps of the viaduct under the sea bed to minimize disturbance to the existing current flow of Airport Channel and shifting the viaduct to the Airport Island once the airport height restriction allows.

Provision of Landscaping Works for At-Grade Road

Provision of Landscaping Works for At-Grade Road

This 1.6 km at-grade road will run along the east coast of the Airport Island with provision of extensive landscaping works.



Formation of a Strategic Road Network

As an integral part of the HZMB project, HKLR will be connected effectively to the HZMB Main Bridge, the nearby Hong Kong International Airport, as well as the Tuen Mun and North Lantau area, to form a strategic road network to achieve overall effectiveness and efficiency in land transportation.

 

Adoption of Tunnel Boring Machines for the Construction of the Sub-sea Tunnel

The proposed sub-sea tunnel crossing the Urmston Road between Tuen Mun South and the HKBCF, will be the longest tunnel in Hong Kong upon completion. It is also the first time in Hong Kong to deploy a 14m large diameter Tunnel Boring Machine (TBM) for excavation underneath the sea bed and the technical requirements are much higher than normal construction works.

 

Besides, for the tunnel section at the reclamation adjacent to Tuen Mun River Trade Terminal, a 17.6m diameter TBM, being currently the largest TBM in the world, has been deployed to provide an additional climbing lane for northbound tunnel (i.e. the number of traffic lanes will be increased from two to three). This TBM is as tall as a 6-storey building or stacking of 4 nos. of double decker.

 

As compared with the traditional immersed tube method, the use of TBM for the sub-sea tunnel construction can reduce the amount of dredging and disposal of some 11 Mm3 of marine sediment, significantly reducing the impact of construction on the environment. The adoption of TBM also saves the need to divert the existing power cables now serving the HKIA, and minimizes the impact on the busy Urmston Road and the marine habitat of the Chinese White Dolphin within and in the vicinity of the works area.

 

The use of large diameter TBMs of this size to build a sub-sea tunnel in Hong Kong is unprecedented and a great challenge to the construction industry in Hong Kong.

The non-dredge reclamation method

Conventionally, seawalls are constructed on firm foundations by replacing the soft marine mud in the seabed by sand fill. This process requires dredging and dumping of a large amount of soft marine mud.

 

With a view to minimizing the environmental impacts caused by the dredging and dumping for reclamation, Highways Department has developed a non-dredge reclamation for reclaiming the 150 ha artificial island for the HKBCF (including about 20 ha of land for Southern Landfall of Tuen Mun-Chek Lap Kok Link) from the open waters off the northeast of the Hong Kong International Airport. This is the first time this new construction method is used in Hong Kong.

 

Part of the seawall* of the artificial island will be formed by sinking large diameter circular steel cells through the soft marine mud. The steel cells will then be filled up by inert construction & demolition material or sand.

 

The adoption of the above non-dredge reclamation will greatly reduce the amount of dredging and dumping of marine mud by about 22Mm3, and will also reduce the use of about one half of the backfilling material. Furthermore, there will be less impact to the water quality and a large reduction in the construction marine traffic during construction of the reclamation works. This will help to preserve the marine ecology especially the Chinese White Dolphins habitat.

 

The non-dredge reclamation has lots of benefits over the conventional dredge seawall construction method, including:
(i) Avoid dredging and disposal of marine mud;
(ii) Reduce backfilling material by about one half;
(iii) Reduce suspended particles by about 70% and
(iv) Reduce construction marine traffic by about one half.

For more details about the non-dredge reclamation method versus the conventional dredge seawall construction method, please press here.

 

Remark* Seawalls of HKBCF includes non-dredged seawall with steel cells and rubble mound and non-dredged rubble mound seawall.

 

Design Features of Passenger Clearance Building

The Passenger Clearance Building (PCB), with construction floor area over 90,000 square meters, is the largest building of the HKBCF. The roof of the PCB is designed in wavy form to imitate undulating waves, matching the sea surrounding the HKBCF island. The roof is supported by tree-like structural columns with few interior structural columns to enhance the feeling of spaciousness in the arrival and departure halls. Controlled natural sunlight will fill the departure hall through skylights and then filter into the arrival hall, thus minimizing the need for artificial lighting. Other energy efficient and environmentally friendly designs will also be adopted to construct the HKBCF in an environmentally friendly manner. The PCB will provide convenient facilities, including convenient and efficient arrival and departure halls at its ground floor and first floor respectively, to be patronised by all HZMB passengers. Drop off lay-bys will be provided in front of the PCB entrances, and passengers can walk to the clearance halls after getting off the vehicle and after completing the clearance process, continue their journey all at same level until pick up. Also, commercial or retail facilities of an appropriate scale will be provided at the PCB to serve and meet passengers’ need.

 

In addition to the sophisticated architectural and structural design, the construction method for the roof of the PCB is also innovative. The roof has been prefabricated in massive modules, which is common in bridge construction but rare in roof construction. Moreover, different from ordinary prefabricated modules, the roof modules have been composed of not only the structural steel frame but also the pre-installed building services works and architectural builder works and finishes, such as aluminum claddings, skylights, smoke vents, baffle ceilings, drainage and lighting system, etc. With this large scale of prefabrication, most works can be completed at the prefabrication yard, hence speeding up the construction progress of the PCB and reducing the risk of working at height.

 

All roof modules are massive and heavy. The biggest and heaviest module is about 60m long, 25m wide and over 670 tonnes in weight. Delivery and installation of such huge roof modules which is the first time ever in Hong Kong, together with the airport height restriction (AHR) on construction works, presents great challenges to the project team. To tackle the AHR, a horizontal launching method has been adopted. The modules have been pushed into position by 4 sets of self-propelled modular transporters and horizontal hydraulic jacks to the top of the PCB and then installed one by one, similar to assembling toy blocks. Every step in the delivery and installation is carefully planned and calculated, so as to ensure smooth connection of all modules.