North-South line, Amsterdam.

When:

9 June 2011

13:00 Hour - 16:00 Hour

Event organizer:North-east region

Description

In Stationsplein 7, you will find an interesting exhibition consisting of many models, photos, films, archaeological finds and an engineering wall.
Traditional and innovative techniques are used in the construction of the North/South Line. In the choice of techniques, limiting disruption to and damage to the surrounding area played an important role. A route was chosen that for the most part lies under existing canals and streets. The metro tunnel will be drilled over a length of more than three kilometres. As a result, buildings will not have to make way for the new metro line. And in addition, the underground stations in the city centre are largely built in covered construction pits.
The different construction techniques per station
Tracé/Stations Technique
Stations Noord Open construction pit at ground level
Sixhaven Open construction pit
IJ Immersion method
Central Station Microtunnelling, immersion method, walls-roof method & sandwich walls
Startshaft Damrak Caisson method
Runway tunnels Tunnel boring technique
Between Damrak, Rokin, Vijzelgracht, Ceintuurbaan and Europaplein
Rokin Station Walls/roof method
Vijzelgracht Station Walls/roof method
Ceintuurbaan Station Walls/roof method
Excavation under increased air pressure
Europaplein Station Open pit
Station Zuid/WTC Open pit
The caisson method may be used in the construction pit. This is only used for a small part of the route: from Central Station to Damrak. The existing East Line was built using this method. In the caisson method, three large concrete boxes are made at street level on a bed of sand. One of these is later used as the starting shaft of the tunnel boring machines. Each tunnel section, or caisson, rests on a kind of cutting edge that protrudes two metres deeper than the floor. This makes it easier for the caisson to find its way into the ground later on. Via stairs and airlocks, caisson workers can get under the caisson. There, they spray the sand loose with water cannons and suck the mud away. In this way, the heavy concrete caisson sinks about 1.5 metres per day. Due to its weight, the caisson automatically sinks into the ground to a solid layer of sand at a depth of 20 to 25 metres. Once the bottom of the caisson reaches groundwater, the airlocks in the caisson are closed. An air bubble is created under the structure due to increased pressure. The high pressure ensures that groundwater cannot enter the working space or that the caisson suddenly sinks too much. Thanks to this air bubble, work can be carried out under the caisson even below the groundwater level. As the caisson sinks further, the groundwater pressure increases and the pressure in the air bubble also increases. The caisson workers can only work under the caisson for a few hours at a time and are under medical supervision. Like divers, they are at risk of getting caisson disease, which is why they must first enter a decompression tank after working to get used to normal air pressure again.

11:30 Arrive and assemble at Smits Koffiehuis, Stationsplein 10, Amsterdam (opposite Amsterdam CS)
11:40 Reception with coffee.
11:50 Lunch with coffee table
12:45 Transfer on foot to Information Centre North-South Line, Stationsplein 10, Amsterdam.
13:00 Start of excursion with introduction, film, viewing maquette.
Following this, viewing caisson north side of the IJ. (free passage with GVB ferry)
Opportunity for questions and discussion.
end of excursion approx. 16:00 hrs.

It is recommended to travel by train to Amsterdam CS. (travel expenses for own account)
Train times from the North Netherlands as an indication:
from Leeuwarden 09:05 a.m.
from Groningen 09:06 a.m.
from Assen 09:24 a.m.
from Heerenveen 09:27 a.m.
from Hoogeveen 09:42 a.m.
Tip: if possible, use the "voordeelurenkaart" (maximum number of travellers with 40% discount per card: cardholder + 3 fellow travellers)