Nws yog tsim rau kev thawb, excavating, backfilling earthwork thiab lwm yam ntaub ntawv nyob rau hauv txoj kev, railways, mines, tshav dav hlau thiab lwm yam av.Nws yog ib qho khoom siv uas tsis tseem ceeb rau kev tiv thaiv hauv tebchaws, kev tsim kho av, kev tsim kho hauv nroog thiab hauv nroog thiab kev txuag dej.