An improved ground motion model considering the seismological characteristics of the Korean Peninsula

In the present study, an accurate ground motion model (GMM) for the Korean Peninsula is developed by considering local seismological characteristics, including source, site, and three-dimensional (3D) path effects. An existing GMM for rock site conditions is adopted as the base model. To enhance the accuracy of this model and incorporate local seismological features, residuals between the observed and predicted intensity measures (IMs), such as peak ground acceleration ( <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll"> <mml:mrow> <mml:mi>PGA</mml:mi> </mml:mrow> </mml:math> ) and pseudo-spectral acceleration ( <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll"> <mml:mrow> <mml:mi>PSA</mml:mi> </mml:mrow> </mml:math> ), are computed. These residuals are further disaggregated into components associated with specific seismological characteristics: <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll"> <mml:mrow> <mml:mi>δ</mml:mi> <mml:mi>Source</mml:mi> </mml:mrow> </mml:math> , <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll"> <mml:mrow> <mml:mi>δ</mml:mi> <mml:mi>Site</mml:mi> </mml:mrow> </mml:math> , and <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll"> <mml:mrow> <mml:mi>δ</mml:mi> <mml:mi>Path</mml:mi> </mml:mrow> </mml:math> . Regression analyses are conducted to develop empirical equations for <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll"> <mml:mrow> <mml:mi>δ</mml:mi> <mml:mi>Source</mml:mi> </mml:mrow> </mml:math> , <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll"> <mml:mrow> <mml:mi>δ</mml:mi> <mml:mi>Site</mml:mi> </mml:mrow> </mml:math> , and <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll"> <mml:mrow> <mml:mi>δ</mml:mi> <mml:mi>Path</mml:mi> </mml:mrow> </mml:math> based on the calculated residuals. These correction terms are subsequently integrated into the existing GMM to establish the improved model. A practical example is provided to illustrate the application of the proposed GMM. The accuracy and reliability of the improved model are validated by comparing the observed IM values with those predicted by the proposed GMM.