Mälarpassage Lambarfjärden 2022 "Pipe Umbrella" (Stockholm Bypass)

Purpose
Due to poor soil conditions, bearing capacity, foundation is needed for a new sewer main in a densely built-up residential area. The purpose is to replace an old sewer trunk.

General Layout
The drilling will be done with a hydraulic hammer system. Water operation of drills is chosen for environmental reasons and with regard to poor rock. Water drilling is significantly gentler on mountains and the surrounding environment.

Preparations before Drilling
Kommer att förberedas av beställaren och borrpunkter mäts och markeras. Borrutrustningen inklusive högtryckspumpen flyttas till borrplatsen.

Method
When the mast is in the right position, the drilling starts. Drilling will be carried out with a hydraulic hammer. A drill rod with an outer diameter of 89 mm combined with a drill bit with a diameter of 4” is used. For drilling, the high-pressure pump provides the necessary water flow (approx. 350 L/min) and pressure to operate the hammer. Drilling depth is between 4-10 m.

Machinery and Equipment