Journal ArticleDOI
Seismic response of shallow foundation on liquefiable sand
Lee Liu,Ricardo Dobry +1 more
TLDR
In this paper, the authors conducted eight centrifuge model experiments to study the mechanism of liquefaction-induced settlement of a shallow foundation, as well as the effectiveness of sand densification by vibrocompaction under the footing.Abstract:
Investigators conducted eight centrifuge model experiments to study the mechanism of liquefaction-induced settlement of a shallow foundation, as well as the effectiveness of sand densification by vibrocompaction under the footing. Two series of model tests were conducted with a surface circular footing placed on a medium-dense saturated sand layer overlying an impervious rigid base. Horizontal shaking simulating an earthquake was used to excite the base of each model in flight; in all cases this shaking liquefied the sand in the free field. The first series of tests concentrated on the effect of the depth of soil compacted under the foundation on the footing acceleration and settlement. Investigators discovered that as the compaction depth increased and approached the total thickness of the soil deposit, the footing acceleration during shaking increased and its settlement decreased. The soil was not densified in the second series of tests; this series focused on the effect of soil permeability on pore pressure buildup and footing settlement. Investigators learned that as the soil becomes more impervious, significant negative excess pore pressures develop under the footing during shaking, and the contribution of postshaking foundation settlement increases while the total foundation settlement does not change significantly. Building settlements observed after two earthquakes in liquefied areas of Niigata, Japan in 1964, and Dagupan, Philippines in 1990, are discussed. Comparisons are made between the field observations and the centrifuge results.read more
Citations
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Journal ArticleDOI
Mechanisms of Seismically Induced Settlement of Buildings with Shallow Foundations on Liquefiable Soil
TL;DR: In this article, a series of centrifuge experiments involving buildings situated atop a layered soil deposit have been performed to identify the mechanisms involved in liquefaction-induced building settlement, including building-induced shear deformations combined with localized volumetric strains during partially drained cyclic loading are the dominant mechanisms.
Journal ArticleDOI
Stone columns as liquefaction countermeasure in non-plastic silty soils
TL;DR: In this article, a saturated silt stratum is analyzed under base dynamic excitation conditions and a series of four separate model tests are performed without, then with stone columns, as a free-field situation, and with a surface foundation surcharge.
Journal ArticleDOI
Centrifuge Testing to Evaluate and Mitigate Liquefaction-Induced Building Settlement Mechanisms
TL;DR: In this article, the authors evaluated the relative importance of key settlement mechanisms by using mitigation techniques to minimize some of their respective contributions and found that the importance of settlement mechanisms depend on the characteristics of the earthquake motion, liquefiable soil, and building.
Journal ArticleDOI
Foundation Liquefaction Countermeasures for Earth Embankments
TL;DR: In this article, a centrifuge-testing program is conducted to assess the earthquake performance of countermeasure retrofit techniques for a liquefiable foundation under an existing embankment.
Journal ArticleDOI
6th Ishihara lecture: Simplified procedure for estimating liquefaction-induced building settlement
Jonathan D. Bray,Jorge Macedo +1 more
TL;DR: In this article, a simplified procedure is developed based on the results of these analyses to estimate the shear-induced component of liquefaction building settlement, which can be used to evaluate building performance at liquefiable sites.
References
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Journal ArticleDOI
Evaluation of Liquefaction Potential Using Field Performance Data
TL;DR: In this article, a simplified procedure for evaluating the liquefaction potential of sand deposits using data obtained from standard penetration tests is reviewed, and the results of this study are then extended to other magnitude earthquakes using a combination of laboratory and field data.
Journal ArticleDOI
Evaluation of Settlements in Sands Due to Earthquake Shaking
Kohji Tokimatsu,H. Bolton Seed +1 more
TL;DR: In this article, a simplified method of analysis is proposed for estimating probable settlements in either saturated or unsaturated sand deposits subjected to earthquake shaking, and the results are shown to compare favorably with settlements observed at six sites for which good data on settlements have been observed.
Journal ArticleDOI
Analysis of Soil Liquefaction: Niigata Earthquake
H. Bolton Seed,Izzat M. Idriss +1 more
TL;DR: In this article, the results of field investigations conducted by Japanese engineers are presented, leading to conclusions concerning the variation of relative density of the sand with depth in regions where liquefaction did and did not occur.
Journal ArticleDOI
Settlement of Buildings on Saturated Sand During Earthquakes
Yoshiaki Yoshimi,Kohji Tokimatsu +1 more
TL;DR: Shaking table tests were conducted on models of rigid structures placed on saturated sand in order to study the pore pressure development in the sand near the structure and study the factors which influenced the settlement of the structure as discussed by the authors.
Journal ArticleDOI
Damage to reinforced concrete buildings in niigata city with special reference to foundation engineering
TL;DR: In this article, the authors analyzed the damage to reinforced concrete buildings in Niigata City due to the 1964 Nissimatsu earthquake with special reference to foundation engineering, and showed that reinforced concrete structures are more vulnerable to earthquakes.
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Settlement of Buildings on Saturated Sand During Earthquakes
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