oilcivil
Civil/Environmental
- May 20, 2010
- 11
Hi There,
In the Petroleum industry in California there is lots of debate regarding pipe supports. Obviously there is lots of opportunity for optimization on a long pipeline with many supports. We typically use a 'T' type support made of cut and welded ERW pipe. We typically have thermal stress on the line that we design for using guides, anchors and expansion loops. However, there are still typically many supports along the line that are only necessary for vertical support. The supports use cast in place concrete piles for foundations. Right now there is a school of thought that all of the supports should have rebar cages in the foundations. I used to be of this school of thought because of temperature shrinkage control comments in the ACI 318. However I just came across a portion of the Plain Concrete section of the ACI that states that cast in place concrete piles are not really covered in the ACI. Additionally, read an old post by GeoPaveTraffic that mentioned rebar cages aren't really necessary for supports only under compression. Regardless, for a support like this, with little (friction) to no lateral forces, I'm not really seeing the need for the rebar cages. Has anyone run into this debate in the past? Are there any codes or standards one would point to? Also if the friction is an issue, couldn't something be places between the pipe and support to limit the lateral friction?
In the Petroleum industry in California there is lots of debate regarding pipe supports. Obviously there is lots of opportunity for optimization on a long pipeline with many supports. We typically use a 'T' type support made of cut and welded ERW pipe. We typically have thermal stress on the line that we design for using guides, anchors and expansion loops. However, there are still typically many supports along the line that are only necessary for vertical support. The supports use cast in place concrete piles for foundations. Right now there is a school of thought that all of the supports should have rebar cages in the foundations. I used to be of this school of thought because of temperature shrinkage control comments in the ACI 318. However I just came across a portion of the Plain Concrete section of the ACI that states that cast in place concrete piles are not really covered in the ACI. Additionally, read an old post by GeoPaveTraffic that mentioned rebar cages aren't really necessary for supports only under compression. Regardless, for a support like this, with little (friction) to no lateral forces, I'm not really seeing the need for the rebar cages. Has anyone run into this debate in the past? Are there any codes or standards one would point to? Also if the friction is an issue, couldn't something be places between the pipe and support to limit the lateral friction?
