CKI-06: Amplification of Strong Ground Motion Due to Local Site Conditions
• Prof. Anne S. Kiremidjian
• Ms. Stephanie King
• Prof. Haresh C. Shah
• Dr. Masata Sugito
The amplification of earthquake ground motion is one of the most difficult parameters to quantify. The difficulties stem from (1) the lack of sufficient data on local soil parameters, (2) lack of sufficient strong motion data at different soil surface locations, (3) lack of strong ground motion data at various depths from the ground surface at the same location, (4) our inability to quantify the nonlinear characteristics of soils and (5) the use of approximate models to represent the nonlinear behavior of soils when subjected to dynamic forces. In this report we present soil amplification factors for peak horizontal acceleration and velocity for earthquakes in the San Francisco Bay region.
2. Soil Parameter and Ground Motion Data Consolidation
3. Ground Motion Amplification Factors
4. Summary and Conclusions
Soil Amplification Characteristics due to Local Site Effect subjected to Stochastic Motion on Rock Surface
• Dr. Masato Motosaka
• Mr. Ariyoshi Yamada
• Mr. Yasuhiro Ohtsuka
• Mr. Masaki Kamata
• Mr. Yasukazu Tsuji
Consideration of the nonlinear and hysteretic nature of the soil behavior under large amplitude cyclic loading is indispensable for realistic estimation of ground motion associated with local subsoil during a strong potential earthquake. Moreover, when estimating ground motion at a specific site, amplification factors are quite sensitive to input motions which are of an unpredictable nature. Therefore, no confidence can be achieved from the results of single deterministic analysis using a recorded or artificially generated motion, especially in the higher frequency range.
To avoid the expense and effort required multiple deterministic analyses, probabilistic (random response) methods have been developed. Such methods require a stochastic description of the earthquake excitation and directly provide probabilistic information on the ground motion, helping the designer to make rational decisions regarding the safety of the facility.
It is the purpose of this study to present a random response methodology to estimate the ground motion considering nonlinear amplification subjected to nonstationary stochastic motion on rock surface considering the source and the propagation path of a strong potential earthquake.
Simplified Methods For The Evaluation of Nonlinear Soil Amplifications Based on Random Response Theorem
2. Review of Previous Papers
3. Methodology For Nonlinear Random Response Analysis
4. Verification of Analysis Methods
5. Application Analysis
Also listed as Report No.: CK92-01 (February 1992)