Dear Mike Dattilio,
Thanks for you reply.As you say, the hot load load-case is the vertical load for GrT1, the cold load load-case is Gr.But I think the thermal movement should be the movement under the hot load load-case (GrT1) - the movement under the cold load load-case (Gr).So,I think the thermal movement is 0.244-0.012=0.232 inch.
Q1：Actually, the spring support just moves between Gr and GrT1.For example, the movement under the hot load load-case (GrT1)=0.205inch, the movement under the cold load load-case (Gr)=0.20inch, and I let the AUTOPIPE select spring when the thermal movement more than 0.1inch, As the AUTOPIPE selects the support is spring ,but I think it should be a rigid support.Where am I wrong?
Q2：In addition,you said the cold load and Gr support reaction are differ slightly.But sometimes them may be differ large.If it has a load variation ratio (note:not (The hot load-the cold preload)/The hot load)can be set in AUTOPIPE? Such as ( cold load(Gr) - support reaction(cold preload))/cold load(Gr)<2%,5%,or10%?
Q3：When the autopipe selects the support,it just uses the the movement under the hot load load-case (GrT1) and the hot load load-case is the vertical load(GrT1). According them, we can caculate the cold preload. (The hot load-the cold preload)/The hot load<=25%(normal),or(The hot load-the cold load)/The hot load<=25%(normal)?When we install the spring support at site,if we need the the cold preload only?
Thanks!