Usually, we regard building structures as stiff. Floors and walls shall not move at any time. Can we tolerate structures that move? Soft structures!

A classic example of soft structures is the Infirmary Suspension Bridge over the river Ness in Inverness, Scotland. This bridge can easily be set in movements by pedestrians (naughty boys!). The bridge was built in 1879, so its durability is unquestionable.

The Millenium Bridge in London wobbled violently in horizontal direction at the opening.

The Python footbridge in Amsterdam’s East Harbour, built in 2000, has highly sensible sway. It has a twisted architecture corresponding to the dynamic behaviour.

Slender balconies and long spanning beams and slabs inside buildings may get sensible vibrations when loaded by walking or running people. Stairs too.

View, sound and psychological effects influence our feelings beside the real physical movements. Big heights and transparent railings may create feelings of vibrations on steady floors – like in the lobby of the Opera Copenhagen, finished in 2004.

What can we tolerate?
What do we like?
I would like to hear experiences and attitudes to these phenomena.
May a panorama tower sway in the wind?
Do you climb the tower in order to get a feeling in your “stomach”?
What if you yourself are able to start the vibrations? Would you do it?
Do you like to climb in trees? Do you look down?
Nobody wonders as a car rocks when a person takes seat in it.
Or when a bicycle sways /wobbles.