Photo: Shanghai Daily
Building in big cities often requires making a difficult choice between progress and preservation. Preserving history is especially challenging in a place like China, which has undergone a dramatic economic transformation over the past few decades. After so many historic structures were demolished to make room for skyscrapers and commercial office towers, there’s been a push for more preservation.
As part of those efforts, the City of Shanghai has recently commissioned an engineering company to “walk” a historic five-story school building to a new location more than 200 feet away so that a new commercial office complex can be built in its original location. It’s an impressive engineering feat, to say the least, and one that could give builders a lot more flexibility in urban construction in the future.
How They Did it
The 85-year-old Lagena Primary School building, located in the eastern part of Shanghai’s Huangpu district, was equipped with almost 200 hydraulic support lifts. Over the course of 18 days, the nearly 8,400-ton structure gradually shuffled to its new location inch by inch, traveling 203 feet and rotating 21 degrees.
A team of workers installed the supports by digging underneath and around the building, Lan Wuji, the project’s chief technical supervisor, told CNN. The newly installed “legs” then extended upward to lift the building before each “step.”
The so-called “walking machine” used for the relocation was developed by a company called Shanghai Evolution Shift. Lan told CNN the support lifts essentially functioned as robotic legs and were split into two groups to mimic human legs walking.
“It’s like giving the building crutches so it can stand up and then walk,” he said.
According to The Urban Developer, Shanghai Evolution Shift claimed using the walking machine accomplished the job 20% faster than it would have by sliding the building along rails or pulling it on a flatbed.
Of course, it’s not to say the procedure was easy. Moving the school presented some unique challenges because of its irregular T-shape. The curved route the building had to follow to get to its new location complicated things even further as previous similar projects in China where historic buildings were moved had all been in a straight line, CNN reported.
With an expected completion date in 2023, the complex that is being built where the school once stood will be a more than 4 million-square-foot mix of office and residential space. CNN reported, the newly relocated school will be renovated and repurposed as a center for heritage protection and cultural education.
Concert Hall Moved with “Walking Machine”
Shanghai is one of the largest and most populated cities on earth, with frequent building and roadway projects changing its landscape. In its shift toward taking the preservation of the megacity’s cultural heritage more seriously, Shanghai has moved other historic buildings to make way for new projects.
CNN writes that in 2003, Shanghai moved its 73-year-old concert hall more than 217 feet ahead of construction of a new elevated highway. In 2013, a six-story 1930s warehouse called the Zhengguanghe Building was moved 125 feet in deference to a local redevelopment project. In 2018, the city relocated a 90-year-old building in Hongkou district.
While Lan wouldn’t reveal the project cost to CNN, he said that generally speaking, moving a building in this manner is less expensive than demolishing a structure and rebuilding it elsewhere.
With urban populations exploding across the US, the coming years will bring more tough decisions about preservation versus progress. If methods like the walking machine see increased uptake, it could mean a future where we no longer have to choose.