Preliminary PEERNGA Ground Motion Model Brian Chiou and
Preliminary PEER-NGA Ground Motion Model Brian Chiou and Robert Youngs PEER-NGA Workshop April 12, 2005
Data Selection • Excluded earthquakes – Gorda plate earthquakes – oceanic crust – Subduction zone earthquakes – Poorly known overseas earthquakes • Northwest China earthquakes • Earthquakes recorded by SMART 1 array – Aftershocks (used only in site effects analysis) • Excluded records – In basements – In large structures – On dam abutment
Modeling Concepts • Source scaling – – – Magnitude (M, M 2. 5 ) No aspect ratio Depth (depth to the top of rupture) Style of faulting (SS+NM vs. RV) Aftershocks not used • Distance scaling – – Closest distance to fault Effect of Q for large distances Break in slope at about 60 km Hanging wall effects, function of fault dip angle
Modeling Concepts (cont’d) • Site Effects – Function of VS 30 (will examine effect using categories) – Nonlinear site amplification (using empirical data guided by modeling results) – Depth to VS ~ 1 km/s
Model Form • Reference site motion (Vs=1130 m/sec) yr • Site effects ys
Amplification relative to Vs=1130 m/sec a b c ln(yr)
Comparison to Site Response Analysis with EPRI Soil Property Model PGA Site Response Analysis (EPRI Soil) Regression
Comparison to Site Response Analysis with Peninsula Range Soil Property Model PGA Site Response Analysis (Peninsula Rage Soil)
Comparison to Site Response Analysis with EPRI Soil Property Model T=1 Sec Site Response Analysis (EPRI) Regression
PGA Comparison to Site Response Analysis with Peninsula Range Soil Property Model
Soft Rock, Strike Slip and Reverse PGA Strike Slip Reverse
Strike Slip Soft Rock and Soil PGA
Strike Slip Soil PGA and 1 Hz PSA PGA 1 Hz
Inter-event Residuals Magnitude Distance
PGA Intra-event Residuals Magnitude Distance
1 Hz PSA Intra-event Residuals Magnitude Distance
T=3 Sec
T=3 Sec
Dip Slip Earthquakes, Records on HW/FW T=3 Sec
T=3 Sec
- Slides: 20