Redeveloping the Double siphon Brooktorhafen
Beside the normal sewers there are a lot of steel pipelines below the rivers and channels ("Fleete") and harbours, so-called siphons, through which since nearly 100 years the sewage is drained off. One of these main sewers has three double-siphons built with so-called "Flußstahl", in order to cross the Upper, Lower and Brooktor Harbours in the Free port of Hamburg. During a rotational inspection 1997, first damages, i.e. corrosion (at the river heads) abrasion in the bottom and leaking joints were assessed. to use the CIPP in this case and asked for offers referring this special renovation case on the basis of a detailed profile of standards and a total quality schedule. Caused by the original kind of installation without any anchoring in the ground of the harbour basin, the pipes cannot be emptied for the purpose of inspection, repair or renovation without the danger of swimming-up. After checking of the tender lnsituform Rohrsanierungstechniken GmbH got the order. Considering the big dimensions of dia 2000 mm, which have to be rehabilitated, and its buckling load (differential water pressure: 2.34 m), a minimum wall thickness of 29.5 mm. ln order to handle this wall thickness and the weight during the impregnation, transport and installation, a double inversion technique was used, installed the two tubes one after and into the other to get the real wall thickness. During the following curing, both layers were joint to one laminate. The first pull-in tube with a weight of round about 25 tons was delivered to the job site. Here it was installed under water into the cleaned pipe, using a special conveyor and a winch, from the "Dükerunterhaupt" (lower head) at Brooktorkai in the free port to the "Dükeroberhaupt" (upper head). The lnsitutube was pulled in carefully under water by defined tractive forces, using the support of buoyancy inside the water. The outside coating of the tube avoid any direct contact of resin with the host pipe and so with ground water or soil and there will be no soaping-effect of the resin before its curing. When the reached the end manhole, the tube was shortened in the start manhole and fixed at the top ring of the inversion scaffold. The whole installation was executed within nine hours.
- Country: Germany
- Region: Hamburg
- Tunnel utilization: Utilities
- Type of utilization: Combined sewage + surface water
- Client: HSE Hamburger Stadtentwässerung
- Contractor: lnsituform Rohrsanierungstechniken GmbH
- Main construction method: Trenchless
- Type of excavation: Renovation, Redevelopment
- No. of tubes: 1
- Tunnel total length: 145 m
- Diameter: 2000 mm
- Contract Volume: approx. 4.2 mill. DM
- Construction start/end: 15 weeks