Cross-boundary and district-level traffic are set to be reduced thanks to the construction of the Liantang/Heung Yuen Wai Boundary Control Point and its connecting road.
The project will be completed by the end of next year and is employing unique engineering techniques to improve efficiency, some being used in Hong Kong for the first time.
When completed, the works will shorten the travel time between Hong Kong and the Mainland, and improve traffic conditions in North District.
Tunnel vision
The 11km Liantang/Heung Yuen Wai link, which includes the 4.8km Lung Shan Tunnel, is a major project linking Fanling Highway and the boundary control point.
The tunnel will be the longest road tunnel in Hong Kong. Its construction has been divided into two sections.
The section between Fanling Highway and Lau Shui Heung requires the drill-and-blast excavation method, which uses explosives to break the hard rock in the area.
The rock in the Lau Shui Heung to Loi Tung section is weaker, so a tunnel boring machine can be used.
To shorten construction time, both sections are being excavated simultaneously.
Civil Engineering & Development Department Engineer Galen Tse said the largest dual-mode earth pressure balance boring machine ever used in Hong Kong is being employed to cut the tunnel. It has a diameter of over 14 metres.
"This machine can operate under different geological conditions and regulate its excavation mode to maintain the balance of the tunnel face pressure in front of the cutterhead. So the excavation progress can be maintained even in different ground conditions.
"Its systems monitor cutter disc wear. The discs are replaced by a robotic arm, reducing the need for manual inspections and repairs, thereby enhancing safety and efficiency."
U-turn
In November 2015 the boring machine started excavating the southbound tunnel from the north portal. In March this year, the machine broke through the end of the southbound tunnel.
At Lau Shui Heung, the contractor has excavated a huge cavern that's 40 metres long, 27 metres wide and 23 metres high. It allows the boring machine to turn from the southbound tunnel to the northbound tunnel to continue excavating.
"The boring machine weighs 3,200 tonnes and is 100 metres long. To turn it around without hitting the cavern requires advanced working methods," Mr Tse said.
The machine is separated into five parts and each is put onto a turntable and turned around. The turntable has a diameter of six metres and weighs about 130 tonnes. The turning process takes three months.
"This method was first applied in Hong Kong and is rare around the world. It saves the cost of producing one more machine and enhances the cost effectiveness of the entire project."
Overhead works
The south portal of Lung Shan Tunnel connects with the Fanling Highway Interchange. It includes the construction of four viaducts that are 4.3km long in total.
The interchange's construction is the largest and most complicated project among the four interchanges along the connecting road.
Civil Engineering & Development Department Engineer Lau Chung-shing said the interchange crosses Fanling Highway and the MTR East Rail.
To reduce the impact of construction work on traffic, the interchange is being constructed by erecting a viaduct segment. The segment lifting frame is used to install the viaduct segment. A segment weighs 46 tonnes.
"To ensure the safety of road users, the installation process needs to be completed in two hours overnight. We have to make sure no objects or tools fall from the work platform to the rail and road."
Direct access
The Liantang/Heung Yuen Wai Boundary Control Point occupies 180,000 square metres at Chuk Yuen near Heung Yuen Wai. It will connect to the eastern part of Shenzhen.
Architectural Services Department Project Manager Keith Tam said it is the first boundary control point with direct access facilities, including drop-off areas for private cars, a 400-space public carpark, a public transport interchange and a pedestrian walkway connecting to Lin Ma Hang Road.
"Passengers can go to the new control point directly by public transport, private car, or on foot which allows for more efficient and convenient travel between the two places."
The passenger terminal buildings on the Hong Kong and Shenzhen sides are connected by a pedestrian footbridge and integrated as one structure.
The new control point will adopt various energy-efficient features and renewable energy technologies, including escalators with motion sensors, water-cooled chillers, a solar water-heating system, and a sewage recycling plant.
Mr Tam said: "The sewage can be used for irrigation after treatment. It can reduce the sewage discharged into the Shenzhen River."
Mr Tse added the Liantang/Heung Yuen Wai Boundary Control Point will be the seventh land-based crossing between Hong Kong and Shenzhen, and will handle 30,000 passengers and almost 18,000 vehicles per day.
The boundary control point and its connecting road will significantly reduce the travel time between Hong Kong and eastern Guangdong, Fujian and Jiangxi.
He added this will not only make a better connection between the economic hinterland of Hong Kong and the Mainland, but also further reinforce the status of Hong Kong in the Pearl River Delta's regional development.
