B008 Lillebru corrugated steel pipe.

The corrugated steel pipe has a lot of corrosion damage and requires renovation. The pipe does not need to be excavated and replaced due to the overlying infrastructure. There are 2 alternative renovation solutions, improvement alternatives 1 and 2, the most economic solution will be chosen. The water supply in the pipe can be turned off by the municipality during the work so that the site area is dry during the construction period.

Improvement alternative 1: A new plastic half pipe is established. The half pipe is fixed to the existing steel pipe and injected with concrete.

Improvement alternative 2: A constructive integral cast is established in the existing steel pipe. The cast is formed with a bottom cast and the walls are anchored with welded connections to the existing pipe. The form from the integral cast in the pipe is to be ended against the existing concrete surfaces upstream, ended at the end of the pipe downstream.

Renovation of bridges B002 and B010, Moss municipality.

Routine inspections have uncovered damages and shortcomings of importance for the load carrying capacity and/or traffic safety on 2 municipal bridges in Moss municipality. A decision has been made to improve these bridges in accordance with the description given in the tender documentation.

The tender documentation consists of 2 different sub projects for these 2 bridges, where the existing bridge constructions are to be partly reestablished. The work is described in reports in Safecontrol engineering, which are attached to the contract, with the accompanying drawings and amounts for the work. A short description of each sub project is given below:

B002 Skredderveien No 1:

The construction's main carrying system consists of corrugated steel pipes approx. ø 3 400 mm (elliptical shape). The pipe's length is 16,30 m.

Critical corrosion with a cross section reduction in the lower part of the steel pipe. No deformation has been proven yet. The concrete wings on both sides of the pipe in axis 1 (west side) is moving and can eventually slip. Other elements (railings, wearing course, filling) do not have damages that are of importance.

Planned measures at Skredderveien No 1:

— The existing pipe is to be cut above the corroded area and a new integral cast is to be established on the existing concrete. The pipe is to be locked in the same way as the existing pipe with a new steel angle with welded reinforcement for the anchoring in the integral cast.

— Concrete wings on both sides of axis 1 (west side) are to be removed and new ones established. Both the wings are proposed to be longer and higher.

B010 Storebru:

The bridge consists of 2 construction stages, a box girder bridge, a recent construction on the downstream side and an older construction, a tubular bridge upstream.

The report includes improvement proposals for the box girder bridge. The tubular bridge has no visible damage that is of importance for its load carrying capacity, and is, therefore, not mentioned anymore in this description. The use class for the tubular bridge is Bk10 in accordance with the Norwegian Public Roads Administration's road lists and the box girder bridge is to be seen as a foot/cycle path.

The continual box girder bridge on the downstream side consists of 3 spans of 9,60, 9,50 and 9,70 m respectively, the total bridge length is 45,50 m.

Planned measures at Storebru:

— Standard mechanical repairs of concrete damage.

— An outlet in the drainage hole must be established.

— Surface treatment on the bottom plate and walls with a diffusion open lining.

— Clearing the manhole/box cross section.

— Surface treatment of railings, both sides of the bridge.

— The railings' fixings at light masts and other loose/missing parts are to be improved/strengthened.