This story features in Unearthed: The Age Of Data

The Hong Kong-Zhuhai-Macau Bridge connects Hong Kong Airport to Macau and Zhuhai across the Pearl River Delta. Its unusual construction combines three cable-stay bridges, one tunnel and a trio of man-made islands. At 55km long it forms one of the longest fixed-links in the world and opens to traffic in July. Seequent’s Ruby Forrester explains what fascinates her about the project.

Why it fascinates me
“Since I left university, I seem to have always lived with other civil engineers! We’ve always had engineering magazines on the table and watched shows such as Megastructures on TV. I imagine I heard about this project through one of those, but I remember thinking that no one had done anything like this before. Combining two civil infrastructure types that even on their own can be complex, was ambitious and innovative. Building just one bridge high enough to let ships pass underneath was not an option, as it would have exceeded the height limit for structures near Hong Kong Airport. But the combination allows ships to cross over the tunneled portion and into the Pearl River Delta. Very clever.”

An incredible project to be part of
“It would have been very interesting to be part of the design team for the bridge-tunnel connection. Developing the structural design of the connection between bridges and the tunnel must have been hugely complex. The manmade islands help, but the potential settlement and coastal erosion would then have dire consequences for the structural integrity of the bridges and tunnel. The transition from caisson foundations for the bridge, to overburden of the soils overlying the tunnel would have been a particularly interesting challenge. Coming from a geotechnical engineering background, I would have loved to help solve these challenges, as I think they’re an opportunity to try something creative.”

How Leapfrog could have helped
“I would have loved to see the entirety of this project built in a Leapfrog model. I think the addition of a seafloor survey with the seabed geology could have been very useful for the bridge design, which could have been informed not only by the geology, but the depth of the water (and the associated horizontal pressures from the water flow). Being able to show the manmade islands in 3D alongside all the other elements would also have been cool. Maybe one day!”

Ruby Forrester
Customer Solutions Specialist, Civil and Environmental
Seequent