Route 3

from Ting Kau to Au Tau

The 11.8 km Route 3 Country Park Section expressway is divided into four major distinctive sections: Ting Kau Bridge and the approach viaduct, the road section leading to the southern entrance of Tai Lam Tunnel, the Tai Lam Tunnel, and the approach road and interchange system at the northern end of the tunnel. This is the most complex highway and tunnel system in Hong Kong.

The 880-metre waterway of the Rambler Channel, which separates the Tsing Yi Island and Ting Kau, is now connected by a cable-stayed bridge which is supported by three independent towers. The foundation of the towers is composed of large-diameter bored piles, anchored to provide better stability in resisting wind. The structure of the towers was constructed in slipforms with the use of 65 mpa high-strength concrete.

Between Ting Kau Bridge and Tuen Mun Highway there is a 510 m approach viaduct that spans Castle Peak Road and Tuen Mun Highway before it reaches the road sections leading to the southern entrance of Tai Lam Tunnel. This approach viaduct was constructed of box-section, cast-in situ concrete by a balanced cantilever method with the use of a traveler formwork system. A slip road made of precast concrete beams supported on high level piers and portals leads traffic from Tuen Mun Highway to Tai Lam Tunnel.

The 3.8 km Tai Lam Tunnel consists of three tubes. Two tubes handle three lanes of traffic each, while the smaller diameter middle tube is a servicing duct for ventilation and maintenance purposes. The Tai Lam Tunnel was excavated using the drill-and-blast method. The contractor employed a series of computer-operated drilling rigs so that the drilling pattern could be accurately calculated.

The drill holes were then filled with emulsion compound and gassing agent to produce the necessary explosion. The crushed rock was excavated and transported to the exit of tunnel by conveyor belt for disposal. The progress of excavation was about 5 m per day at the peak. As soon as the excavation was completed, a concrete lining was formed by the use of a large mechanical form system so as to strengthen and seal the exposed rock surface permanently.

The tunnel excavation started simultaneously at both north and south ends. The works at the south and north ends were carried out by Dragages and Nishimatsu, respectively. Unlike other tunnel designs, there is a ventilation building on both ends of the Tai Lam Tunnel. This building is so designed that it also serves as the entrance to the Tunnel.

There is a 6.2 km approach road leading traffic from the northern end of the Tai Lam Tunnel to Au Tau through Kam Tin area. In addition to the construction of the approach road, this part of the project also included the construction of the toll square and the administration building for the tunnel joint-venture consortium, as well as a slip road and interchange system leading to Yuen Long Bypass and Kam Tin Road.

As for the construction of the approach road, there were several major rock cuts between Shek Wu Tong and Ko Po. Difficulties encountered in this part of work were mainly due to the scale of rock cutting as well as some major fractures in the cut rock requiring further stabilisation using anchor systems.

main contractor
Route 3 Contractors Consortium
Nishimatsu Construction Co Ltd/Dragages et Travaux Publics (HK) Ltd

 

Country Park Section:
A Very Special Highway Project


Ting Kau Bridge, at the northern end of the Rambler Strait, is one of the major sections linking Route 3 from the north-western New Territories to Kowloon. This photo was taken in July 1997, when the first section of the bridge deck in the middle tower could barely be seen.

The steel tower head rests on the 29 m radius cofferdam on the Tsing Yi side. It will be lifted to the top of the tower after final inspection. The lifting bracket on the right side has already had the strands tightened to the strand-jack on top of the tower.

Detail of the climbing form used to construct the Ting Kau bridge tower. The form is hydraulically lifted and is on a 2-3 day cycle; each lift is about 3.8 m. The tube within the reinforcing bars is for the placement of steel tendons for post-tensioning work at a later stage.

A detailed look at the top of the bridge tower. A steel gantry with two pairs of strand-jacks was erected on top of each tower to lift the 190-tonne steel tower heads on which the cable anchors are housed. The 4.5 m x 31 m slot on the top of the tower is for the placement of the tower heads.

Detail of the steel gantry on top of the bridge tower. The strand-jacks seen at the far end are mounted on a sliding platform. The two steel tower heads have been initially positioned at this stage. A pair of one-metre-thick concrete tie walls, one on each side, will be placed at the back of the tower head, securing them in position and stiffening the top of the bridge tower.

December 1997: the bridge as seen from the Tsing Yi side looking towards Ting Kau. The 1,177-metre cable-stayed bridge is supported by three towers, with the 200 m middle tower being the tallest. Erection of the steel/concrete composite deck started from the tower on Ting Kau towards the Tsing Yi side, with a lapse of about a month between each tower. At the peak of construction, six frontages were provided at the ends of the deck sections, making the progress of work extremely fast.

Workers using hand block are preparing to fix a PE sheath to the anchor head at the bottom of the tower head. The PE sheath is for the protection of the stay cable. The black nozzle-like tube is the anchor head.

The bridge tower with the radiating network of stay cables.

Inside the steel tower head, the stay cables (each composed of up to 60 15-mm strands) are stressed to pre-determined strengths using a hydraulic jack. The stress load for each cable depends on its position on the bridge deck.

As the bridge is a single-tower design with decks on both sides, a separating slot connected by cross girders, is formed between the two decks. This slot provides an aerodynamic effect and helps stabilise the bridge structure under strong wind. The steel anchor heads for the stay cable and transverse cable can be seen here.

Close-up of one of the derrick cranes on the working front of the deck. The crane is rail-mounted to limit its movement.

A 38-tonne, 18.8 m x 13.5 m segment unit is hooked to the derrick crane cable and lifted to deck level.

A 6-tonne, 15 sq m precast concrete panel
is placed between the girders of the composite
segment unit to form the sub-slab of the deck.


Typical set-up for deck erection as seen from the Ting Kau bridge tower. The deck on the trunk of the tower was initially erected by forming a working base with standard struts and girders. Four derrick cranes are lifted by strand-jack to the base for onward extension of the bridge deck on both sides. In order to stabilise the partially completed deck from wind, the deck was temporarily anchored with tie cables.

This photo shows the central tower with the two cantilevered spans partially completed. When completed and connected to the decks on the adjacent towers, the cantilevered deck will have a clearance of 448 m and 475 m on each side of the central tower, giving a spacious waterway for ships entering into the Rambler Channel.

The deck as seen from the side of the bridge. The cross strut is strengthened by stabilisation cables which stiffen and support the deck.

The deck seen from the end piers of the Ting Kau approach viaduct. A gap of less than 15 m remains, awaiting the final connection.

The connection of the deck to the Tsing Yi Abutment, as viewed from the top of the tower. The layout of the precast concrete panels which form the composite deck structure is clearly shown.

The bridge deck as seen from the underside. The cross struts that rest on the waist of the tower, the main and cross girders, and the underside-mounted sliding work platform, can be seen in the photo.

Detail of the bridge abutment on the Tsing Yi side. This abutment is designed to house the bridge expansion joint. Rows of nozzle-link tubes are the dead anchors for the stay cable (those on the tower head are known as stressing anchors).

The formwork gantry used to construct the box section viaduct. The construction spread outward, section by section, from the central pier. When a four-metre section is completed and the concrete is cured, the gantry on top of the deck slides a section forward, suspending the form below to repeat the construction of the next section.

Looking up to the approach viaduct. The viaduct, which was constructed using a balanced cantilever method, spans Castle Peak Road 60 metres below.

The layout arrangement of the approach viaduct on Ting Kau as seen from the top of the bridge tower. Castle Peak Road, Tuen Mun Highway, and the entrance to Tai Lam Tunnel are barely visible.

The slip road from Tuen Mun Highway to Tai Lam Tunnel was constructed using two different methods. The section near the approach viaduct utilised a balanced cantilever method due to its larger span. The farther section, as seen in the photo here, is constructed of precast beams with in situ reinforced concrete deck. To overcome the problem of access, a temporary mini-rail was erected on the deck of the slip road.

The layout arrangement of the approach viaduct and the slip road at the junction with Tuen Mun Highway.

Close-up of the mini-rail transporter and the launching machine used to install the precast beams for the slip road deck.

A 700 m x 150m x 90 m section links the approach viaduct at Ting Kau and the Tai Lam Tunnel. The road was cut from hard and highly abrasive granite, and the photo shows rows of 100 mm bore holes, drilled to a 12 m depth in staggered layers to facilitate the blasting process.

The 700 m road cut looking towards Ting Tau. Rock cutting was done in two benches at different levels. The excavated rock was crushed on the spot by a track-mounted crushing unit and delivered using a conveyor system which can be seen atop the small hill on right.

The 8 m shovelling machine (pictured with the track-mounted crushing unit linked to the mobile conveyor) works swiftly and efficiently at each cutting spot due to its 4 cu m capacity.

Two cutting spots are being set up on this 150 m wide road cut. The excavated and crushed rock is delivered by mobile conveyer to a collection hopper, which rests on a section of temporary track, allowing its position can be easily adjusted as the cutting locations proceed.

Crushed rock from the road cut and the Tai Lam Tunnel excavation is delivered by a two-kilometre conveyor system that passes through tunnels and valleys before reaching Gemini Beach on Castle Peak Road for disposal by barge.

The southern entrance to Tai Lam Tunnel. The tunnel consists two main 16 m tubes which can handle three lanes of traffic each, with a 6 m ventilation duct in the middle. Unlike other Hong Kong tunnel designs, there is a ventilation building on both ends of this tunnel, eliminating the classic hood-like entrance.

Formation of the concrete lining for the tunnel interior. The steel structure with rows of lights as seen in the photo is the track-mounted, highly automatic formwork. The sides and top of the formwork (with seals on the ends) are shutters which shape the tunnel section. By pumping in of the concrete, a 180 mm concrete lining is formed. Compaction is accomplished by the use of attach-on vibrators.

Paving work inside the tunnel; The cladding panels on the two sides were not installed at this stage.

Workers inside the ventilation tunnel. Since this tunnel is strictly for maintenance purposes, costs were minimised by eschewing the usual concrete lining. A rock bolt system with spray-on concrete lining was used to strengthen the surface of the exposed rock.

A look of the ventilation building on the Kam Tin side. This building is also the entrance to the Tai Lam Tunnel. The opening at ground level on the right side is the entrance to the southbound tunnel. The front of the building will be used as traffic control for the tunnel, while the majority of the ventilation building is for mechanical and service use.

Connecting an open section of the tunnel tube to the ventilation building using usual timber formwork. This photo was taken at the north end of the Kam Tin side.

Exiting from the tunnel, a 6.3 km approach road system cuts across the north-western edge of the Kam Tin Plain, eventually directing the traffic to Route 2 at Au Tau and to slip roads at the Yuen Long southern bypass.

The slip road at Au Tau takes the form of a viaduct passing over wetlands. It is constructed by a segment launching machine using precast box section girder units.

The road complex at the Au Tau interchange.

Along the Yuen Long approach road, showing
the 60 m high rock cut and the magnificent
storm drainage system.

Route 3

Kwai Chung Section

Route 3 (Kwai Chung Section) is one of the ten Airport Core Projects. This section runs from the south and joins the West Kowloon Expressway at Mei Foo. From there, it extends along Kwai Chung Road and rises to become an elevated expressway in the form of a viaduct. When approaching the Lai King MTR station, it turns to the west to Kwai Tai Road, and then joins the Rambler Channel Bridge, running alongside Terminal 1. After reaching the approach bridge on the east coast of Tsing Yi Island, Route 3 runs directly into the Cheung Ching Tunnel. Then it goes through a section of associated expressway to reach the Tsing Ma Bridge. This section will ultimately connect with the Ting Kau Bridge in the Route 3 (Country Park Section).

The total construction cost of the 6.8 km Route 3 (Kwai Chung Section) is $3.9 billion. The project comprises three basic elements: Kwai Chung Viaduct; Rambler Channel Bridge; and Cheung Ching Tunnel. The following photographs illustrate and explain the construction process of the viaduct.

The construction method is not as complicated as one might expect. At the start, the pier or portal frame is constructed to support the bridge deck. Precast concrete beam members of various cross-sections are erected by specially designed launching equipment to span the portals. Reinforced concrete is then placed on the top of the precast beams so that the bridge deck can be formed. However, in order to cope with the design requirements and actual on-site conditions of each section, three different methods and segment launchers must be used during construction.

The 2.2 km section of the viaduct that runs from Kwai Chung Road to Kwai Tai Road makes use of 34 m U-section beams to form the deck. The beam members are erected by a segment launcher with 160-tonne capacity that "walks" on top of supports above the portal frame.

In constructing the lighter Airport Railway Viaduct, box-section beam and girder-type segment launchers are used. As for the 600 m section of expressway running along Terminal 1, as well as the Rambler Channel Bridge, large box-section beam and pedestral-type segment launchers with 250 tonne capacity are used.

The following photographs go into greater detail.

 


The starting point of Route 3 (Kwai Chung Section) on the southern tip at Mei Foo. The West Kowloon Expressway that conveys traffic from the Western Harbour Crossing can be seen in the background. In this section of road, other facilities, including the branch road to Mei Foo and the Airport Railway Maintenance Depot, can be seen.

Route 3 - Kwai Chung Viaduct typical section.

From the Mei Foo to Rambler Channel Bridge section, Route 3 is an elevated expressway, 3 km in length. The construction of this section makes use of precast U-section beams with an average span of 34 m, which are lifted to the top of the portal by the beam launcher. In the early stage of construction, a portal frame constructed of in-situ concrete is used to support the precast beams and the bridge deck on top. The supporting rail of the launcher is then erected on the top of the portal frame. By using this launcher, the precast concrete beams are lifted and placed on the frame to support the bridge deck. The red steel beam seen in the photo is the supporting rail of the launcher. The Airport Railway Viaduct can also be seen below the portal frame.

Since the segment launcher is used to lift the precast beam vertically, traditional corbel projected from the portal cannot be used to support the precast beam. A steel clip is applied to support and fix the precast beam temporarily in this case. Tensioned steel tendons are applied to tie the precast beams both front and back. Finally, reinforced concrete are placed on top in order to stiffen the beams, as well as to form the surface of deck. The red rows in the photo are the temporary steel clips.

After passing through the Rambler Channel Bridge from the Tsing Yi side, Route 3 runs into Kwai Tai Road and joins the Airport Railway again. This section, as a result, becomes a 25 m-high, double-deck elevated expressway. The segment launcher and the supporting rail can also be seen in the photo.

The most magnificent section of Route 3. Essentially, the whole construction process can be seen here. In the upper right corner, the segment launcher has lifted the precast beams on the portal frame to form the bridge deck. The precast beams in the centre of the photo have been tightened on the frame by the use of tensioning, and thus, the temporary steel clips have been removed. The bridge deck on the left has had the reinforcement fixed. On the far left side, concrete placing to the bridge deck can be seen.

The full view of the segment launcher. This launcher system starts from the Mei Foo section, and lifts the precast beams onto the portal frame to become the bridge deck. When finishing one section, the system slides on top of the frame to the next section and repeats the work. By using this method, the segment launcher occupies fewer ground spaces. The launcher slides from Mei Foo to the interchange before the Rambler Channel Bridge to complete this dual four-lane viaduct. When the project is near completion, the launcher will be dismantled at the interchange.

The operation sequence of the segment launcher (A): the precast beam is transported by trailer to the launching position, under the segment launcher that is placed between two portals, and is ready for lifting.

The operation sequence of the segment launcher (B): The segment launcher has lifted the precast beam to the level of the bridge deck.

The operation sequence of segment launcher (C): The segment launcher transports the precast beam to the required position on the portal, making use of a sliding action on the supporting rail.

Seating detail of the pier of Airport Railway Viaduct and the box section beam on the top of the pier.

Smaller precast box section beam that was lifted by a girder-type segment launcher is used to build the viaduct of the Airport Railway. The overall view of the segment launcher can be seen in this photo. This method allows for occupation of fewer ground spaces and the road can remain basically unobstructed during construction.

Part of the temporarily erected precast beams are hung by the girder of the launcher. When the lifting of the whole section is completed, all the beams will be tightened by a tensioning technique. The launcher will then slide to another section to repeat the work.

Workers are positioning the box section beam members that hung temporarily on the girder-type segment launcher, so as to facilitate the tensioning work later. The setup on top of the girders on both sides is the cable winch that can slide along rails atop the girders.

The largest pedestral-type segment launcher, which is used to construct the Rambler Channel Bridge. This launcher has three sets of hydraulic controlled pedestrals, which can slide both forward and backward, and move up and down. By using these pedestrals, the launcher with 200-ton capacity can "crawl" on top of the bridge deck to carry out the lifting work of the larger box-section beam members.

Close-up look at part of the pedestral-type segment launcher. One of the large pedestrals, the cable winch car on the girder and the control cabin can also be seen here.

Interior view of the box-section beam member. The two iron rods on the underside are used to straighten and tighten the beam members, before the tensioning work can be effectively applied.

Work platform suspended on the segment launcher and the hydraulic jack for tensioning work that is placed on the platform.

Platform-type transporter, which can deliver 40 tons of precast members.

The end section of the bridge deck viewed from the bottom of the launcher.

The launcher uses its cable winch car to transport a beam member to the deck for erection.

Hydraulic-operated semi-automatic moulding machine that is used in the precast yard to construct the box section beam.

There are two precast yards on the site for the Route 3 (Kwai Chung Section) projects. One is located between Mei Foo and Container Terminal 6; another is located at the former Kwai Chung Park. Shown in this photo is the precast yard near Mei Foo. Some precast U-section beam members can also be seen, which will later be transported to the required position for erection.

The steel mould that is used to cast the U-section beam. The precast beam member, steel tendons for pre-tensioning and the hydraulic stressing device can also be seen.

The launcher is lifting the box-section beam from the transporter and delivering it to the required position for erection.

Close-up detail of the elevating platform. This platform can deliver materials or other equipment weighing up to 80 tons to the deck level.

A corner of the precast yard, located at the former Kwai Chung Park. The large gantry crane shown in this photo is working with the box-section beam members. A transporter, which can be seen at the bottom of the photo, will be raised to the deck by the use of the elevating platform.

The segment launcher erects the Airport Railway Viaduct on the lower deck of the double-deck bridge system.

The most complicated section of the elevated expressway is located at Kwai Tai Road, running a length of about 450 m. Here, the Rambler Channel Bridge begins to connect with the road system near Terminal 1. Also, the Airport Railway that runs from Tsing Yi Station intersects here and forms a double-deck viaduct. This photo shows the working arrangement of the large portal frame in its early stage, on which the double-deck bridge will be placed.

Outside the Lai King MTR Station, Route 3 intersects and connects with the existing road system in Kwai Chung. One section of the road bridge, as shown in the photo, will lie on top of the existing MTR rails. The complicated falsework system, which is used to support the new bridge and to protect the MTR rails during construction, can also be seen here.

The first box-section beam of the Airport
Railway has been placed on top of the pier
as the starting member. Hydraulic jacks
will then be used to adjust the beam to
form the final alignment and gradient of
the bridge deck. Finally, when the beam
has been tightened by steel tendons, the
lifting of other members within the section
can be carried out.