Demolition in the centre of HelsinkiPublished 10/7, 2017 at 12:55
The demolition of the nine storey Kasarmintori buildings in the centre of Helsinki, Finland was presented at the recent DDR Expo and Forum in Brussels. PDi reports.
The Kasarmintori buildings were built in 1959 and 1969 and used as office and business premises. They were built in connection with two neighbouring buildings and had double basements that ran adjacent to a separate courtyard basement. The area was about 20,000m²/floor and demolition created about 29,000t of demolition waste.
Demolition work was done high above ground level and workers might have been exposed to chemical substances to classification VNa 205/2009, which are considered dangerous work.
The time frame for the demolition project was quite tight and the project had to be finished in only four months. In addition the working hours were limited between 8am and 4pm during working weeks and no working was allowed during weekends or public holidays. The logistics operations in the city area were constrained and could only take place during 8am to 4pm and not at weekends. Demolition materials were transported off site between 10 to 15 loads/day.
Work method – part 1
The Pohjoisesplanaadinkatu Street was closed and used as an operations platform, while the adjacent street was turned into a two-way road. The first demolition operation was to create an entrance to the centre courtyard. Demolition was conducted normally until it became clear that the neighbouring building did not have a shared structural wall as the documentation indicated otherwise. Light demolition was undertaken after structural inadequacies became clear through excess vibrations. The frame of the wall was partly cast on the brick composition and anchors were attached to the ground.
Work method – part 2
Demolition was conducted normally and since this building was at the corner of an active two-way street, it was necessary to take safety precautions. A crane was used to support different size protective heavy masts. To reduce the dust on site dust suppression cannons with water mist where used. Light demolition was undertaken after structural inadequacies became clear via excess vibrations. The same operations were undertaken again due to structural inadequacies.