It is difficult to dig the ground when it is frozen hard 地面凍硬時(shí)不易挖掘。
She used a spade , which you use to dig the ground . she dug it up and it fell ; and she dug it up again and it fell again . i said , " no , you cannot do that . 她用一支你們用來挖土的那種鏟子去挖它,她把它挖起來,它就掉下去,她又挖起來,它又掉下去,我說:不行!
As an unexcavtion technology , pipe jacking have an unique excellence for it need not dig the ground surface . so it have been used widely in civil engineering 頂管法作為非開挖的技術(shù)中的一種,可以在不用開挖地表土的情況下將管道鋪設(shè)完畢,具有無可比擬的優(yōu)點(diǎn),其應(yīng)用也越來越廣泛。