Deconvolved Intensifying Artificial Accelerations (DIAA): Theory and application in geostructures

In the context of soil–structure interaction analysis, the deconvolution process for computing effective earthquake loads within rock profiles holds significant importance. This study explores the implications of this process on structures founded on rock with linear response and high shear wave velocity. The structures are subjected to both real ground motions and intensifying artificial accelerations (IAA). By employing detailed nonlinear finite element simulations on a concrete dam with a massed foundation, two distinct scenarios are explored. In the first scenario, all selected motions are deconvolved to the specified depth, and the resultant equivalent nodal forces are used. The second scenario involves treating the input excitations as outcrop motions, with corresponding effective earthquake loads directly applied to the depth. The outcomes underscore that neglecting the deconvolution process for real ground motions leads to an overestimation of structural responses. The magnitude of this discrepancy remains uncertain and is influenced by ground motion aleatory variability and damping ratio. Concurrently, this paper introduces a practical framework that circumvents the deconvolution process for IAAs, while upholding an acceptable level of accuracy. The deconvolved IAAs offer simplicity of use and expedite the risk assessment process for complex geostructures.