20 December 2018
Surabaya, Indonesia: an impressive retaining wall failure
Posted by Dave Petley
Surabaya, Indonesia: an impressive retaining wall failure
On Tuesday night (18th December 2018) a spectacular retaining wall failure occurred in Surabaya in East Java, Indonesia. This landslide destroyed a 30 metre long section of the four lane Jl. Raya Gubeng, causing considerable traffic delays in the area. Images of the aftermath of the event suggest that it was a very substantial failure:-
TRhe aftermath of the large retaining wall failure in Surabaya, Indonesia on Tuesday. Image via Tempo.
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An article in the Malaysian Star has various statements confirming that it was a retaining wall failure:-
National Disaster Mitigation Agency (BNPB) spokesperson Sutopo Purwo Nugroho said the sinkhole was caused by a construction error.
“The retaining wall was not able to withstand the load, especially during the rainy season,” he said in a statement, adding that there was no connection between this incident and two active earthquake faults in Surabaya and Waru.
Surabaya Deputy Mayor Wisnu Sakti Buana said the sinkhole was allegedly related to the construction of a parking basement at Siloam Hospital.
“This is related to the project on the side of the road. The Siloam Hospital project. They were supposed to build a foundation first, but they didn’t,” Wisnu said as quoted in an interview with KompasTV.
Surabaya Development Planning Agency head Eri Cahyadi concurred, saying the incident was purely caused by an error in the project.
Meanwhile, Sutupo Purwo Nugroho also tweeted this image of the site, apparently showing the wall prior to failure:-
The retaining wall that failed at Surabaya, East Java in Indonesia on Tuesday night. Image Tweeted by Sutupo Purwo Nugroho.
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Fortunately reports suggest that there were no casualties in this failure. Videos of previous events have shown how dangerous they can be.
Acknowledgement
Many thanks to Robert Kwok for highlighting this very interesting event to me.
Dave Petley is the Vice-Chancellor of the University of Hull in the United Kingdom. His blog provides commentary and analysis of landslide events occurring worldwide, including the landslides themselves, latest research, and conferences and meetings.
Retaining walls can go very bad, very, very quickly.
Be NOT there…
I’ve relatives in Mexico City, and one was proudly showing me pics of the lovely, new-build apartment block he’d helped design, that his growing family had just moved into. A ‘gated’ complex, with its own swimming pool at the front, a splendid retaining wall holding up the hill behind…
I’m no expert, but the wall seemed to be low on ‘batter’, and certainly lacked the geo-technical grid you’d expect.
I complimented him on the superb interior design, then asked if the pool had ‘seismic’ isolation and a flexible, fracture-resistant liner. From his expression, apparently not. It was supposed to be the block’s emergency water supply in case of mishap or mayhem. They had pumps, ash-filter, everything. But, without such isolation, even a mild tremor could lose the contents overnight, gurgle, gurgle, gurgle…
Then I asked how well that tall, very steep retaining wall was drained and rock-bolted into the area’s less-than-predictable strata, and how had they stabilised the slope above. He paled further, downed his stiff drink in one gulp…
When their initial year’s contract was up, we got a ‘change of address’ note…
Oh my gosh that’s horrible, freaks me out. I hope the people working on my yard know what they’re doing, would hate to see something like this happen