2022 2.2km (1.4 mile) Tseung Kwan O – Lam Tin Tunnel in Hong Kong

West portal: (Satellite, it was still under construction when I accessed it.)

East portal: (Satellite)

I've seen spaghetti interchanges before, but this is the first time I've seen an interchange deep in a hole. This interchange is the connection of the west portal of this Tseung Kwan O – Lam Tin Tunnel (tko-ltt) on the right with the east portal of the Cha Kwo Ling(CKL) Tunnel, which is still being built, on the left. The ramps coming up from that tunnel-to-tunnel connection provide access to the Eastern Harbour Crossing Tunnel and the local roads. This hole also contains ventilation and administration buildings.

td.gov.ky

tko-ltt_overview

The east portal is easy to understand. It simply connects to the west end of the Tseung Kwan O Cross Bay Bridge.

tko-ltt_photos, Dec 2022

Another view of the west portal. Effectively, they are building a new expressway in a tunnel along the bay. But here they daylight that new tunnel to build an interchange with the local roads and the existing Eastern Harbour Crossing Tunnel. By daylighting, I mean they dug a hole in the hill down to the grade level of the new tunnels.

tko-ltt_photos, Dec 2022

The satellite map caught them still digging the hole.

Satellite

I zoomed into the lower-left part of the above to show the temporary bridge for a haul road. Look at the queue of trucks waiting to backup and dump dirt directly into a barge.

Satellite

They plan to add a lot of landscaping. Evidently the greenery helps suppress the road noise.

roadtraffic-technology
"The tunnel is being constructed using either the mechanical method or the conventional drill and blast method, depending on geological conditions and site constraints."

I think the whole tunnel was done with the drill and blast method. I saw no evidence that a tunnel-boring-machine was built for these bores. I did see evidence that blasting was done.

aurecongroup
"Aurecon utilized the GIS platform to map out the location of the buildings that might get affected by the drill and blast work."

aurecongroup
"Aurecon's Steven Haslemore proposed a spatial solution that replaced the manual drill and blast calculations being conducted by the team."

Another vision of the landscaping. When I saw that an interchange on the east side of the tunnel was built over water, it occurred to me that blowing away the side of a mountain is one way to get the needed land in a very dense urban area.

LeightonAsia

Unlike some of the very impressive infrastructure work that China is doing in the western part of the country, the rush hour traffic on the bridge that connects to this tunnel shows that there is heavy traffic in this area.

Highway Engineering Discoveries posted via Dennis DeBruler