DESIGN SPECIFICATIONS FOR HIGHWAY BRIDGES - IISEE

6.3 Verification of Seismic Performance Level 1 for Earthquake Ground Motion ...... 20
6.3.1 General ........................................................................................................... 20
6.3.2 Calculation Method of Inertia Force ............................................................. 20
6.3.3 Design Horizontal Seismic Coefficient .......................................................... 21
6.3.4 Verification of Seismic Performance Level 1 ................................................. 22
6.4 Seismic Performance Verification for Level 2 Earthquake Ground Motion .......... 22
6.4.1 General ........................................................................................................... 22
6.4.2 Calculation Method of Inertia Force ............................................................. 23
6.4.3 Design Horizontal Seismic Coefficient .......................................................... 24
6.4.4 Force Reduction Factor .................................................................................. 27
6.4.5 Performance Verification for Seismic Performance Levels 2 and 3 ............. 27
6.4.6 Performance Verification for Reinforced Concrete Columns ........................ 28
6.4.7 Performance Verification for Pier Foundations ............................................ 29
6.4.8 Performance Verification for Abutment Foundations .................................. 31
6.4.9 Performance Verification for Superstructures .............................................. 31
6.4.10 Performance Verification for Bearing Supports ........................................... 31
Chapter 7 Verification Methods of Sesmic Performance based on
Dynamic Analysis ...................................................................... 32
7.1 General ..................................................................................................................... 32
7.2 Design Earthquake Ground Motions for Dynamic Analysis .................................. 32
7.3 Analytical Models and Procedures .......................................................................... 33
7.3.1 Analytical Models and Procedures ................................................................ 33
7.3.2 Modeling of Structural Members .................................................................. 33
7.4 Verification of Seismic Performance ....................................................................... 33
Chapter 8 Effects of Seismically Unstable Ground ................................... 36
8.1 General ..................................................................................................................... 36
8.2 Geotechnical Parameters of Extremely Soft Layer and Sandy Layer Prone to
Liquefaction ............................................................................................................. 36
8.2.1 General ........................................................................................................... 36
8.2.2 Assessment of Extremely Soft Soil Layer in Seismic Design ....................... 36
8.2.3 Assessment of Soil Liquefaction .................................................................... 36
8.2.4 Reduction of Geotechnical Parameters ......................................................... 39
8.3 Verification of Seismic Performance of Foundations for Liquefaction-induced
Ground Flow ............................................................................................................ 40
8.3.1 General ........................................................................................................... 40
8.3.2 Calculation of Lateral Force on Foundations by Liquefaction-induced