Foundation Performance of the Millennium Tower in San Francisco, California: Three-Dimensional Settlement and Tilt Analyses
Publication: Geo-Congress 2022
ABSTRACT
The Millennium Tower is a pile-supported 58-story building constructed in San Francisco, California, between 2005 and 2009. As a result of time-varying stress changes in an over-consolidated clay layer below the pile tips, the foundation has settled and tilted at variable rates. Settlement and tilt have been measured since 2006 and 2009, respectively. As part of a broader analysis of this case study, we describe here three-dimensional simulations of stress increases in foundation soils, groundwater changes beneath the tower, and foundation settlement and tilt. The analyses are performed in FLAC3D using a calibrated soft soil creep model to capture the effects of secondary compression. Stress changes in the underlying clay layer are computed using the Tower self-weight and time-varying dewatering at the Tower and adjacent sites. Groundwater changes with time and foundation movement are compared to observations with reasonable agreement. Companion papers present the case study and one-dimensional settlement analyses.
Get full access to this chapter
View all available purchase options and get full access to this chapter.
REFERENCES
Arup North America, Ltd. (2010). Transbay Transit Center Program: Transbay Transit Center, Volume 7A/B, February 26.
Bjerrum, L. (1967). “Engineering geology of Norwegian normally consolidated marine clays as related to settlement of buildings.” Géotechnique 17 (2): 83–118.
Brandenberg, S. J. (2017). “iConsol.js: A javascript implicit finite difference code for nonlinear consolidation and secondary compression.” Int. J. Geomech. 17 (6): 04016149.
Casagrande, A. (1938). Notes on Soil Mechanics – First Semester, Harvard University (unpublished), 129 pp.
Holtz, R. D., Kovacs, W. D., and Sheahan, T. C. (2011). An Introduction to Geotechnical Engineering, 2nd Edition. Pearson.
Itasca. (2019). FLAC 3D (v. 7.0): Minneapolis, Minn., Itasca.
Kutter, B. L., and Sathialingam, N. (1992). “Elastic-viscoplastic modelling of the rate-dependent behaviour of clays.” Géotechnique, 42(3), 427–441.
Mesri, G., and Choi, Y. K. (1985). “The uniqueness of the end-of-primary (EOP) void ratio-effective stress relationship.” In Vol. 2 of Proc., 11th Int. Conf. on Soil Mechanics and Foundation Engineering, 587–590. Rotterdam, Netherlands: A.A. Balkema.
Taylor, D. W., and Merchant, W. (1940). “A theory of clay consolidation accounting for secondary compression.” J. Math. Phys. 19 (1–4): 167–185.
Vermeer, P. A., and Neher, H. P. (1999). “A Soft Soil Model that Accounts for Creep.” Proc., International PLAXIS Symposium: Beyond 2000 in Computational Geotechnics, R. B. J. Breinkgreve (ed), Amsterdam, 249–261.
Wagner, N., Largent, M., Curran, H., Murphy, D., Butkovich, J., Nouri, H., Egan, J. A., and Stewart, J. P. (2022). “Foundation Performance of the Millennium Tower in San Francisco, California: One-Dimensional Settlement Analyses” Proc., Geo-Congress 2022, ASCE, Charlotte, NC, March 20-23.
Wagner, N., Largent, M., Stewart, J. P., Beyzaei, C., Murphy, D., Butkovich, J., and Egan, J. (2021). “Stress History-Dependent Secondary Compression of San Francisco Bay Region Old Bay Clays.” J. Geotech. Geoenviron. Eng., ASCE, 147 (7), 04021045.
Information & Authors
Information
Published In
Geo-Congress 2022
Pages: 669 - 678
History
Published online: Mar 17, 2022
Authors
Metrics & Citations
Metrics
Citations
Download citation
If you have the appropriate software installed, you can download article citation data to the citation manager of your choice. Simply select your manager software from the list below and click Download.