Support Reaction

Can someone please tell me how to use the results that are contained in the Support Reaction print-out? I gather that, for a model to be structurally correct, the values there should all be zero; none of the springs are supposed to be carrying any forces. Is this always true? And if there are non-zero values, how is this "error" fixed? Do the spring constants have to be adjusted, or does the correction have to be made in the Spring Tension/Compression specification? I am analyzing an underground structure using a beam-spring model with underground conditions approximated by radial and tangential springs. Any information about how to use and analyze the information in the Support Reaction print would be greatly appreciated. Thanks!!

  • Are you talking about  I assume so, though the question could also apply to RAM Elements, RAM Concept, or AutoPIPE to name a few.

    Springs are, by default, linear-elastic supports and by no means would I expect the spring reactions to be zero. You can make springs compression-only and in that case you are looking to eliminate tensile reactions. Normally that’s automatic, but if the structure is not completely stable, then some tension in your compression only springs might still result. If that happens, there is usually a global stability issue that needs to be addressed, by providing more resistance to overturning for example.

    There is an excellent forum exchange on springs here: