SCEC Broadband Platform (BBP) ground motion simulations for tall building response analyses in San Francisco, Los Angeles downtown, and CyberShake sites

Ting Lin, Gregory Deierlein, Kuanshi Zhong, & Wen-Yi Yen

Published September 2020, SCEC Contribution #10792

Earthquake science and engineering face data challenges particularly related to (1) the absence of ground motion recordings in metropolitan areas of high seismicity and (2) the lack of response analyses of tall buildings subjected to extreme motions. This paper focuses on (1) earthquake scenario simulations that lead to a new ground motion database under SCEC Broadband Platform (BBP) and (2) demonstration building responses that cover different first-mode periods of vibration with higher-mode effects. Sites in urban areas include San Francisco and Los Angeles downtown where many tall buildings are located, along with a near-fault site located in San Bernardino as part of the SCEC CyberShake project. To illustrate building code application and performance-based engineering analysis, a range of intensity levels are covered including design-based earthquake and maximum considered earthquake. Ground motions are selected per ASCE 7-16 building code criteria to match target spectra calculated using USGS design tool or according to the Conditional Spectra and significant duration using a computationally efficient ground motion selection algorithm, resulting in sets of eleven or one hundred ground motions for each building, site, and intensity combination. Nonlinear (dynamic) response history analyses of a 20-story reinforced concrete frame and a 42-story reinforced concrete shear wall are performed on OpenSees enabled by high performance computing, generating displacement, acceleration, and collapse response data that can be linked back to the causal earthquake rupture because of end-to-end simulations. The novelty and significance of this pilot study are discussed to demonstrate how geophysics-based ground motion simulations can be best used in advanced structural engineering research. The companion demonstration BBP ground motion sets are made available via SCEC and DesignSafe simulation data release to encourage broader utilization of ground motion simulations in the engineering research and practice communities.

Key Words
SCEC Broadband Platform; ground motion simulation validation; tall building; spectra; near-fault effects; CyberShake

Citation
Lin, T., Deierlein, G., Zhong, K., & Yen, W. (2020, 09). SCEC Broadband Platform (BBP) ground motion simulations for tall building response analyses in San Francisco, Los Angeles downtown, and CyberShake sites. Oral Presentation at 17th World Conference on Earthquake Engineering (17WCEE).

Related Projects & Working Groups
Ground Motion Simulation Validation