Repair measures to sewers from the outside involve especially the replacement of single or several damaged pipes.
In this case, after placing the section of the sewer out of action, the defective pipe region is exposed using the open cut method (Image 22.214.171.124-1), a closer pipe piece with smooth ends is inserted and the new pipe joint is remade with the aid of sleeve joints (Image 126.96.36.199-2) (Image 188.8.131.52-3) [FI-Naylo] [FI-Stein93].
The advantage of the sleeve joints is their flexibility that permits different settling between the disturbed and undisturbed soils.
In all excavation works, the provisions of EN 1610 [DINEN1610a] and the protective measures for work safety must be taken into consideration. Special precautions must be taken to ensure that nobody is injured by collapses and that no neighbouring supply and drainpipes are damaged. The safe working of machines and especially sufficient working space for the operating personnel must be ensured [DINEN752-7].