Hong Kong–Zhuhai–Macau Bridge

INTRODUCTION

The Hong Kong–Zhuhai–Macau Bridge (HZMB) is a 55-kilometre (34 miles) bridge-tunnel system consisting of a series of three cable-stayed bridges, an undersea tunnel, and four artificial islands. It is both the longest sea-crossing and the longest open-sea fixed link in the world. The HZMB spans the Lingding and Jiuzhou channels, connecting Hong Kong, Macau, and Zhuhai — three major cities on the Pearl River Delta.

Originally set to be opened to traffic in late 2016, the structure was completed on 6 February 2018 and journalists were subsequently taken for a ride over the bridge. On 24 October 2018, the HZMB was opened to the public after its inauguration a day earlier by Chinese leader Xi Jinping.

The functions of the bridge are to meet the demand of passenger and freight land transport among Hong Kong, the mainland (particularly the region of Pearl River West) and Macao, to establish a new land transport link between the east and west banks of the Pearl River, and to enhance the economic and sustainable development of the three places. The bridge reduces the transit time from Hong Kong to Zhuhai from several hours to around 30 minutes.

SECTIONS OF THE BRIDGE

Construction of the HZMB project began on 15 December 2009 on the Chinese side and construction of th hie Hong Kong section of the project began in December 2011 after a delay caused by a legal challenge regarding the environmental impact of the bridge.

The 55km HZMB consists of three main sections: the Main Bridge (29.6 km) in the middle of the Pearl River estuary, the Hong Kong Link Road (12 km) in the east and the Zhuhai Link Road (13.4 km) in the west of the estuary.

Main Bridge

The Main Bridge, the largest part of the HZMB project, is a bridge-cum-tunnel system constructed by the mainland Chinese authorities. It connects an artificial island, housing the Boundary Crossing Facilities (BCF) for both mainland China and Macau in the west, to the Hong Kong Link Road in the east.

Hong Kong Link Road

Under Hong Kong jurisdiction, the Hong Kong Link Road was built by the Highways Department to connect the Main Bridge to an artificial island housing the Hong Kong Boundary Crossing Facilities (HKBCF). This section includes a 9.4-km (5.8 mi) viaduct, a 1-km (0.62 mi) Scenic Hill Tunnel and a 1.6-km (1.0-mi) at-grade road along the east coast of the Chek Lap Kok.

Zhuhai Link Road

The Zhuhai Link Road starts from an artificial island housing Macau, passes through the developed area of Gongbei via a tunnel towards Zhuhai, and connects to three major expressways, namely, the Jing-Zhu Expressway, Guang-Zhu West Expressway and Jiang-Zhu Expressway.

CONSTRUCTION METHODS

Long-span viaducts

The HKLR viaduct section features long spans as the carriageway crosses two navigation channels and Sha Lo Wan Headland, a designated Site of Archaeological Interest, where no construction works were allowed. A massive, bespoke straddle carrier was used to construct the long-span viaduct of 180m in length. At the time it was erected, it was the longest, dual three-lane prestressed precast concrete bridge.

Automated People Mover (APM)

An APM transport travellers from the Hong Kong BCF to the Hong Kong International Airport Island via a tunnel. The tunnel has been constructed with the cut-and-cover method and mining method similar to the Hong Kong LR tunnel. However, for the marine portion of the tunnel, the immersed tube method has been used. The immersed tube method consists in the immersion of several premade tunnel units that are then assembled with the underground portions of the tunnel.

Environmental innovative reclamation technology

Non-dredge reclamation was the first-ever reclamation method adopted in Hong Kong. It greatly cut the amount of dredging and dumping of marine mud by about 22 million m3 and reduced the use of approximately half of the backfilling material.

This led to a lower impact on water quality and less marine construction traffic during the building stage. This helped to preserve marine ecology, especially the habitat of the Chinese white dolphins.

Other Innovative methods adopted

• Floating concrete batching plant was introduced, which was the first of such facilities in Hong Kong and significantly reduced the logistics and ensured the best quality of concrete produced.
• The construction of two separate tunnel tubes of the HKLR to cross under the existing Airport Express Line (AEL) is one of the most challenging works for the HZMB project in Hong Kong.
• As the AEL is an important railway link between Hong Kong International Airport and the central business district, the normal and safe operation of the AEL must be maintained at all times.
• To ensure undisrupted operation of AEL during the tunnelling works, box jacking was adopted — the first time it was used at such scale in Hong Kong. It involved pushing the constructed tunnel box segments forward by hydraulic jacks sequentially in a “caterpillar” motion, with a design jacking force of 19,400 tonnes — enough to lift 70 empty Airbus A380s in one go.

IMPACT ON WILDLIFE

Environmental groups say the project may have caused serious harm to marine life in the area, including the critically rare Chinese white dolphin. Conservationists at WWF Hong Kong blamed the construction of the HZMB for the falling number of white dolphins in the waters near the bridge. The dolphins found near waters of Lantau were worst hit with numbers dropping by 60 per cent between April 2015 and March 2016.

SOME MORE FACTS ABOUT HZMB

• Designed to withstand earthquakes and typhoons, it was built using 400,000 tonnes of steel, enough to build 60 Eiffel Towers.
• The bridge cost about $20bn (£15.3bn)
• Chinese officials say it will generate up to 10 trillion yuan ($1.44tn)
• The HZM Bridge is designed to last for 120 years and an addition of 40 years with proper maintenance.
• Only 19 workers died during the construction while more than 600 were injured

Even though critics have called the bridge a “big white elephant” that guarantees no economic return. But it is also true that the construction methods used to build the world’s longest sea-crossing are magnificent. Truly the bridge is an inspiration to the future civil engineering projects and there’s no doubt in the beauty and performance of the Hong Kong-Zhuhai-Macau Bridge.

Author: Gurleen S

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