Positioning of double T-beams at Hoog Catharijne, Utrecht

The construction company BAM is implementing the Hoog Catharijne New Construction project in Utrecht. This project consists of various complex sub-projects in an inner-city area. Koninklijke Saan is carrying out various tasks on behalf of BAM during this long-term construction project. Below we describe one of the complex lifting projects carried out. This related to the horizontal movement in a construction trench of 21 concrete double T-beams, after which they had to be lifted to a position that was very difficult to access in the “Poortgebouw” (gatehouse building) sub-project.

BAM initially approached Saan for advice in connection with lifting the double T-beams. BAM has its own fixed tower crane on rails in the construction trench. Because of the great weight of the beams (22 tonnes) and the required move (100 metres) BAM could not move them on its own with its fixed tower crane. The space in the construction trench was very restricted. Moreover, the space at ground level was very restricted because of the inner-city location of the project. As a result, moving the beams was made more difficult and it was not possible to assemble a large mobile crane in the construction trench.

Saan set to work on producing a suitable solution and came up with an ingenious and advantageous method for moving the double T-beams to their final positions. The plan was assessed by BAM, taking into account the maximum floor load, and approved. Saan was then awarded the contract for its implementation. The contract was carried out as follows:
– The existing differences in level in the construction trench were levelled out by means of wooden excavation mats.
– A 70-tonne off-road crane was lifted from ground level into the construction trench by a 400-tonne Liebherr LTM1400-7.1 mobile crane from Saan. This crane was then driven under its own power to the other side of the construction trench.
– A sledge system with a winch (anchored to the ground) was built on the bottom of the construction trench to move the double T-beams horizontally.
– Each beam was lifted separately with the 400-tonne crane and then placed on the sledge and winched to the lifting position.
– The beams were lifted into their final positions with the 70-tonne mobile crane and the fixed tower crane on rails.
– Two beams could not be put in place because of the position of the fixed tower crane on rails in the construction trench. These two beams were temporarily positioned next to the gap in the beams that had already been positioned. After the dismantling of the fixed tower crane, a gantry crane was assembled over the gap to lift the two remaining double T-beams into position.
A challenging job which was carried out by Saan’s employees with care and enthusiasm and which resulted in a nomination for the 2016 Esta Awards.