Recent content by swengi

Hi HotRod10 Thanks again for the helpful response. In this instance we cannot change the design. However, I may be able to consider this approach for future designs. It's good to be aware of the potential issues with oil secretion for elastomeric pads and neoprene. Do you know if rubber...

Hi SlideRuleEra Yes, you are correct. We are certifying and therefore not trying to change the design. Any suggestion of improvement is purely for my own edification, as I may have to design one of these clamps myself at some point. Thanks!

Hi HotRod10 Thanks for the suggestion. I haven't come across fabric (cotton duck) pads before. Do you have any idea of the coefficient of friction one could expect when using these pads? Also, with the steel bearing plates and concrete seats, I assume that the loads are stabilising? In our...

Hi desertfox The collar is a bespoke design so unfortunately, no manufacturer specs are available! Thanks!

Thanks SlideRuleEra & Lomarandil. I usually can find good sources for design online, in codes or other reference material. I have had to utilise critical thinking and combine different methods for designing non-standard items in the past, e.g. dolly for pile hammer under impact loading, which...

Hi Lomarandil Thanks for the response. This is my first time coming across the friction collar. I do a bit of bridge formwork but not tons. It seems that there is no good published literature or design guides for these connections and engineers are relying solely on empirical advice. Thanks!

Hi LittleInch The clamp is like the rigid type in your picture and SlideRuleEra's diagram above. It is not the band clamp, which is pinned on one side. However, I have used this analogy in my calculations. I know it is not 100% technically correct. Apologies, this is my first time posting...

Hi LittleInch As we are certifying the design and not the original designer we have limited scope to change it. In fact, I believe these clamps have already been fabricated. If I were designing this structure from the outset, I would have pushed for a positive connection through the pier as...

Hi SlideRuleEra You are on the money. That is the exact application this clamp is being used for (short-term). We are supporting the pier headstock formwork off the clamp, in addition to a couple of levels of working decks for access. I did use the paper you cited in our design checks and...

Hi jgKRI Thanks for your response. This is where I was trying to get to. I understand that the answer will not be simply 200kN or 800kN but rather will lie somewhere in between. I was hoping there might be some method of analysing the connection other than FEA, although it sounds like it may...

Hi LittleInch The clamps are semi-circular in two halves, with a 250mm gap between the halves on each side of the configuration. The four bolts are each side of the clamp configuration. When the bolts are stressed, the two halves are pulled together to close the gap. Hope that makes sense...

Hi This is my first post on this Forum. I'm interested to see what responses there are to my query as I'm having difficulty getting an answer from Dr Google. My problem is as follows: We have been asked to certify a clamp. The clamp is a steel collar around a 2800mm DIA reinforced concrete...