The security of freezing wall is the key problem of freezing shaft sinking in deep alluvium.

冻结壁的安全性是深厚冲积层中冻结凿井的关键问题。

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The security of freezing wall is the key problem of freezing shaft sinking in deep alluvium.

冻结壁的安全性是深厚冲积层中冻结凿井的关键问题。

youdao