Influence of the Depth of Embedment on Seismic Earth Pressures on Basement Walls


Abstract eng:
Observations of the performance of basement walls and braced retaining structures in recent earthquakes show that failures of basement or deep excavation walls in earthquakes are rare even if the structures were not designed for the actual magnitude of the earthquake loading. For instance, no significant damage or failures of retaining structures occurred in the recent Wenchuan earthquake in China (2008) and the subduction earthquakes in Chile (2010) and Japan (2011). Current design methodologies compute large dynamic loads due to seismic earth pressure that have not been observed in practice. Additionally, while recent research has acknowledged that embedment effects should be incorporated, no specific provisions have been proposed or adopted. To explore this issue a series of centrifuge scale experiments was carried out with different structures and different types of backfill, as follows: 1) a 6 m deep “stiff” non-displacing cross braced retaining structure; 2) a 6 m deep “flexible” non-displacing cross braced retaining structure and 3) a 13 m deep “stiff” non-displacing basement structure. Comparison of the experimental data to current design methodologies using standard procedures and interpretations (e.g., free field peak ground acceleration as the design acceleration) shows that these are over-conservative and that the depth of embedment is important when dealing with basement structures. Using a seismic coefficient, 𝑘𝑘𝑀𝑀𝑀𝑀𝑀𝑀𝑀𝑀 , corresponding to the maximum depth-averaged acceleration rather than PGA results in better agreement between observed centrifuge data and the computed design load. Numerical analyses using FLAC2D corroborate the results.

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Conference Title:
Conference Title:
16th World Conference on Earthquake Engineering
Conference Venue:
Santiago (CL)
Conference Dates:
2017-01-09 / 2017-01-13
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Text je chráněný podle autorského zákona č. 121/2000 Sb.



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 Record created 2017-01-18, last modified 2017-01-18


Original version of the author's contribution as presented on USB, paper 1023.:
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