We have a tunnel inspection coming up on a Wastewater tunnel. The tunnel was built in 1999 and will be inspected after approx. 25 years in service.
In addition to a normal tunnel inspection this sewage transfer tunnel has a 600mm dia. GRP pumping main running in the left-hand shoulder of the tunnel connected to the lining via 4 x M12 Hilti anchors at 2m spacings along the pipe. Thankfully, the drawing indicates that Hilti HY150 HAS-R stainless steel resin injection anchors have been used.
I wanted to check the condition of the anchors and their ability to support the pumping main satisfactorily. As the pumping
main is in service / use, I don’t want to carry out a destructive test on the fixings. But I would like to confirm that the bolts don’t have any defects (cracking or corrosion) and can hold the proof load.
Do you have any experience of non-destructive testing of anchor bolts or could provide advice on how I could develop an NDT inspection spec ?
Thanks for your question, HY150 is an old product and I've attached an extract from a 2005 design manual which should help in relation to loading and tightening torque etc. If you know the original design details you could look potentially at a 'Proof Load Test' which is basically an assessment of the installation quality as all design details were known and designed accordingly. You'll find a couple of sources of information such as BS8539:2012 or the Onsite testing guidance note published by The Construction Fixings Association . I believe the standards agency used this as the basis of their document.
