Soil cavities discovered underneath Soyuz-2 launch pad at Vostochny spaceport

[Satori]

MOSCOW, September 10. /TASS/. Repairs must be carried out at the launch pad for Soyuz-2 carrier rockets at the Vostochy spaceport in Russia’s Far East after cavities were discovered in the soil underneath a servicing tower, a source at the spaceport told TASS.

"Cavities appeared underneath the reinforced concrete foundation of a mobile servicing tower at the first launch pad of the Vostochny spaceport," the source said. "We have already concluded a contract to eliminate the cavities."

The source did not specify the origin of the cavities at the launch pad of the spaceport in Russia’s Far East, while the Center for the Operation of Ground-Based Space Infrastructure refrained from making comments on the situation.

The first launch site at the Vostochny space center was built in 2012-2016 for Soyuz rockets and the first launch from it was carried out on April 28, 2016.

More:
http://tass.com/science/1020705

[chepomic]

The source did not specify the origin of the cavities at the launch pad...

The Russian version

https://tass.ru/kosmos/5547008

is much more descriptive, and it spells out the cause of the cavities in the very title: Low-quality concrete.

[Stan Black]

Выполнение работ по ликвидации пустот под железобетонным основанием спецпути МБО сооружения 1 Стартового комплекса РН «Союз-2» на космодроме «Восточный»

http://www.zakupki.gov.ru/223/purchase/public/purchase/info/common-info.html?regNumber=31806893008
http://www.zakupki.gov.ru/223/purchase/public/purchase/info/common-info.html?regNumber=31806893283

[russianhalo117]

High pressure concrete grout and other mining and ground stabilization technologies would likely to be used.

[russianhalo117]

The source did not specify the origin of the cavities at the launch pad...

The Russian version

https://tass.ru/kosmos/5547008

is much more descriptive, and it spells out the cause of the cavities in the very title: Low-quality concrete.

Sounds like the concrete highways in my state that were built using high Alkali containing sand which breaks down from the humidity and rain. So a highway (motorway) designed to last 200 years lasted 7 to 12 years.

[SciNews]

Baikonur has cavities too, different culprits though