In practice, soil structure interaction is handled by modelling the soil as a spring system in the computer model. The Structural Engineer should not calculate these values, but require the Geotechnical Consultant to provide them.
In an onshore project, I find that it is best to ask the...
The Superelement (6 x 6 matrix) is used when performing dynamic applications (vibration, fatigue, eismic etc).. it is the recommended method to be used for such analyses.
I would only use the permanent weight and not the hoisted load for the seismic analysis.
The hoisted load is not fixed to the structure and will not contribute to the exciting force
I assume that you are checking an existing riser which is partly corroded so u have a problem with code requirements to pass the riser CSR.
If that is the case, I would suggest adding more supports for the riser using subsea mechanical clamps or guides, such that the unsupported spans are...
most of the RP2A requirements are now performed by software.
It appears that you may be starting to work on offshore structures..so you will most likelyt be using softwre like SACS, STRUCAD, SESAM or others..
In these softwares, you will be able to perform all analyses and code checking through...
The seismic forces normally occur at the center of mass of the structure.
The seismic design using international codes and standards can be done using an equivalent static method or dynamic analysis.
The equivalent static method calculates seismic forces, which is normally higher on the top and...
You can use rule of thumb such as:
weight of footing / weight of machine = 2 -5 depending on the type of machine (centrifugal or receprocating).
Alternatively, you can perform a detailed dynamic analysis of a footing using British Standards CP???? sorry the number escapes me at present.
There...