We know that Harmonic response has three possible sources like vibration through Pump, Pulsation and FIV. All these sources are in direct contact with the system.
If we have a operating/moving machinery in the vacinity of a burried pipe, e.g. VIBROHAMMER is excavating under & over a burried pipe (Pipe is no more burried in this local area now, say 6 sq. meter pipe is bare rest is burried).
We have frequency of equipment, amplitude, and velocity of this hammer. We also have soil data. But we don't have this vibration data right on the pipe.
Can CAESAR II incorporate this perticular case and how?

As we all know, CAESAR only considers displacement in the form of beam elements, and simplifies the stress calculation due to the beam displacement.

If the soil vibrations are capable of causing the soil to compact and slump, then if you have the displacements, you could apply the displacements to the pipe, and still have the soil restraints be flexible.

You would have to cnode all the restraints to otherwise unused node numbers, and the apply a displacement on the element with the restraints and cnodes to the otherwise unused node number. I.E. if your pipe was 10-20-30 before burial, and then becomes 10,11,12,13,14...30 after burial, you'd then use 1010, 1011, 1012, 1013, 1014... 1030 as cnode numbers.

However, if the proximity and severity of the vibration equipment are close and large, the failure mode could be localized. The soil would be "flowing" away and towards the source of the vibrations, which I speculate could exert a localized pressure on one side of the pipe, causing rapid ovalization. CAESAR doesn't address this. The energy placed into the pipe will be a function of the soil material and the pipe material, I'm sure, but there's not a large amount of experimental data to design to.

Thanks Michael, unfortunately proponent does not allow us to start any activity in this area, unless we satisfy him by some written proof that this hammer induced vibration will not harm his system.
Though vibration of hammer in soil would exert some vibrations on pipe. What if I assume this vibration just like harmonic response by a reciprocation compressor (i.e. Soil is sending vibrations on my pipe like a pump, I guess noise as well to some extent but it could be ignored.

If you can guide, what are limitations if I try to generate earthquake spectrum of this case?

Even your source is harmonic, vibration propagates in soil by a number of wave types or "modes" which are often called Rayleigh waves of different order and Love waves. They are rather parallel to the surface, however in a layered soil structure with a stiff soil as substructure and in addition having a slope, the things are to a PhD thesis without a software. I have no idea about such software, by the other hand. I mean I'm not optimistic you'll solve by calculation.


About your question: in my opinion, your spectrum should be amplitude spectrum and/or velocity spectrum rather than acceleration spectrum, anyway. How to obtain them and how use such spectra in Caesar, this is another question...