THE EQUIVALENT FORCE SYSTEM OF A MONOPOLE SOURCE IN A FLUID-FILLED OPEN BOREHOLE

The elastodynamic body-wave field outside a fluid-filled open borehole due to a monopole source in the fluid, is reduced to the radiation-field due to a suitable equivalent force system (EFS) in the absence of the borehole, consisting of a monopole plus a vertical dipole. Our results confirm the notion that boundaries in elastodynamical configurations can be replaced by force systems which may reproduce with sufficient accuracy, part or parts of the total field. Thus, our EFS excludes tube waves. -from Authors