Monitor for new container terminal

Advanced instrumentation is in place to safeguard the new container terminal to be built in Kristiansand. "We must have good control of what happens in the ground during backfilling," says design geotechnical engineer Carl-Fredrik Davidsen of Norconsult.

The Port of Kristiansand IKS is one of the country's busiest ports. 5,000 ship calls and 1.5 million passengers from ferries and cruise ships are big numbers. In addition, there is general cargo, fish, offshore and containers.

A new container terminal at Kongsgård/Vige will soon be under construction. It will replace the current terminal at Lagmannsholmen. There will be urban development. At Kongsgård/Vige, work is underway on land and in the sea where masses will be filled in. The new container terminal outside the city centre will be a modern terminal with increased capacity and efficient solutions.

Unique installation

Cautus Geo has installed a customised SAAV Subsea inclinometer.

- The installation is designed to be used under special conditions, including various offshore installations. We developed the installation procedure together with Norconsult Boreteknikk," says Lars Steinar Hefre of Cautus Geo.

The SAAV Subsea inclinometer is mounted VERTICALLY 28 metres into the seabed. It registers horizontal deformations in two axes along the entire measurement string.

- "We installed the system in special ground conditions, through a rock fill ten metres above the clay. In other words, it's complicated," says Kristoffer Kåsin of Norconsult Boreteknikk, who was involved in developing the installation method to establish automatic measurements in the seabed.

Horizontal measurement

The SAAV Subsea inclinometer will automatically detect any sliding movements. Data is sent continuously to Cautus Web. Limit values will be set there. If they are breached, an alarm is sent to the project management so that work can be stopped and measures assessed.

- For large infill projects in the sea, it's important to monitor how the ground responds to the load. The instrumentation provides us with continuous data on deformations in the ground, so that we can detect any movements at an early stage and ensure safe execution of the work," says Davidsen.

The instrumentation is installed through the rockfill and further down into the underlying clay masses, anchored in rock. The inclinometer itself is set about two metres into the rock to ensure stable reference measurements. The pore pressure is also monitored.

The area closer to land will be filled in to make room for the new, modern terminal and the reorganisation of Vige Harbour Road.

New road and quay

The instrumentation that Cautus Geo has now established will provide the Port of Kristiansand with insight into and control over how the ground reacts during backfilling for the new harbour road and the first stage of backfilling for the new terminal.

Initially, 130,000 cubic metres of stone will be filled in.

- "We expect this part of the work on the re-routing of the Vige harbour road to be completed in early summer this year," says Davidsen.

The project involves extensive groundwork, including backfilling in the sea and the establishment of counterfills to ensure stability during the development.

Urban development

Urban development at Lagmannsholmen is linked to the new container terminal. The project also includes the rerouting of Vige Havneveg. It will be both redesigned and partially rebuilt with 700 metres of new road towards Ringknuten.

The project also includes the establishment of a new water and wastewater network, two new high-voltage substations and new underground cable routes for future electricity supply to ensure shore power for ships.

EQUIPMENT:

• Cautus Web - real-time analytics and insight solution with alert and alarm.
• SAAV - 3D Subsea inclinometer at 28 metres.
• 6 pore pressure gauges - various depths down to 25 metres below the seabed.
• CL3 loggers and a Campell - on land, wired to the instrumentation at sea.