As you probably know, cracks occurred in the first deviator on site without struts, even though a load test has demonstrated that it could carry much higher force than ULS. When we went to site we saw that the duct was squeezed against the top of the bell mouth. This shouldn’t happen, and we therefore went to the yard to find out why.
Attached pls find sketch and photo of the diabolo used for the portal beams. It consists of 2 parts connected with an HDPE duct. The length carrying the upward force from the tendon is reduced from 400 mm to 340 mm, which I am sure you agree is unfortunate. It doesn’t explain, however, why the duct hit the top of the bell mouth. One explanation may be skew installation of the diabolo.
Since no viaduct has been erected yet, but many segments are cast, I worry that the same diabolo invention has been used for the viaduct, which may cause more problem on site. Please send me a sketch of viaduct diabolos and check with your staff how they are connected in the yard before casting.