Your question is tangential to my understanding , hence probably cannot answer properly. Few words of advise: In case of buried pipes, inertial loading is not of any significance because of obvious reason. The issues of importance are peak ground deformation, fault line crossing , seismic wave propagation etc. There is a report addressing these issues by Professor S.K.Jain of Indian Inatitute of Technology Kanpur which was prepared after the ALA document and this document is available in the internet ( do a google search).
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anindya