Opportunity
The bridge will support a dual three-lane carriageway over the Pearl River Estuary – one of the world’s busiest shipping channels. Formed from pre-stressed concrete box sections, the bridge will be constructed using the balanced cantilever method. The total length of the crossing is approximately 41.6km, of which 12km is in Hong Kong territory and 29.6km is in Guangdong. A scheme using a bridge and tunnel combination has been adopted for the main part of the crossing within mainland territory.
As well as the large scale of the project, there was a range of physical conditions to be overcome during the construction of HZMB, including the sub-tropical weather, typhoons and heavy rain and the hydrology and hydrodynamic aspects of the Pearl River estuary. Other factors included the geotechnical complexity of the site, the multiple navigation channels with high numbers of shipping movements and height restrictions for nearby airports. The HZMB also crosses environmentally sensitive areas — particularly the conservation area of the Chinese White Dolphin — which meant that high standards of environmental protection were set to minimise any effects on the marine ecosystem and fishery resources.
Solution
We were appointed by Dragages-China Harbour-VSL Joint Venture as the lead designer for a 9.4km viaduct at the Hong Kong end of the bridge. The consultancy also provided geotechnical, highways, electrical and mechanical, utilities and other civil engineering services on this section of the project.
We were appointed by the Authority as the quality management advisor for the Hong Kong-Zhuhai-Macao Bridge, which meant reviewing contractors’ quality control plans and monitoring construction of the first component of each item within the list defining our scope of work. We also conducted regular site inspections of the work to assess the implementation of quality control measures.
We also supervised the design and construction of the 30km Chinese section of the link, including a major cable-stayed bridge, two man-made islands and a 6km long immersed tube tunnel across the Pearl River estuary.
Outcome
HZMB was clearly a project of national and international significance and the desire was to ensure that it was constructed to the highest standards. The Three Governments and the Authority had a target to achieve a 120-year design life for the crossing, with normal levels of regular maintenance.
As lead contractor designer of the 9.4km viaduct at the Hong Kong end of the bridge and quality management advisor of the China Section, we helped the HZMB Authority ensure the construction of a substantial section of the HZMB bridge is completed to world class standard. Once operational, HZMB is expected to reduce travelling times between Hong Kong and Zhuhai or Macau by road to approximately 40 minutes, down from the current time of four and a half hours. HZMB will also enhance economic and sustainable development around the Pearl River estuary, one of the world’s biggest shipping channels.