tag:blogger.com,1999:blog-76868463409565053.post878566465307404288..comments2023-04-15T16:57:59.715+01:00Comments on Travelling the Cambridgeshire guided busway: Concrete beamsAndrew Bethunehttp://www.blogger.com/profile/02711423177266767155noreply@blogger.comBlogger1125tag:blogger.com,1999:blog-76868463409565053.post-13412445590502981252012-10-30T12:48:07.619+00:002012-10-30T12:48:07.619+00:00Talking with some engineering colleagues, the cons...Talking with some engineering colleagues, the consensus was that the notches are "stress concentrators" and are deliberately put there to induce cracks at that location - ie on top of the mid-beam support - rather than in random other locations where they might be more damaging in the long-term.<br /><br />The Cambs busway has more cracking than others due to the long span (7.5m between supports) and we have measured the "sag" between supports to be about 0.5cm (without load). The sag will increase with the weight of a bus on top of it, but we have not measured this (yet). It is this sag which causes the vertical jolting particularly evident on the double-decker buses.<br />Stephen Lawrencehttps://www.blogger.com/profile/00649392649827111837noreply@blogger.com