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3. FEM analysis of dynamic soil-pile-structure interaction in liquefied and laterally spreading ground

Author

Chang, D, Boulanger, R, Brandenberg, S, and Kutterb, B

Subjects
Strategic, Defence & Security Studies, Civil Engineering, Strategic, Defence & Security Studies
Abstract

A two-dimensional nonlinear dynamic finite element (FE) model was developed and calibrated against dynamic centrifuge tests to study the behavior of soil-pile-structure systems in liquefied and laterally spreading ground during earthquakes. The centrifuge models included a simple structure supported on pile group. The soil profiles consisted of a gently sloping clay crust over liquefiable sand over dense sand. The FE model used an effective stress pressure dependent plasticity model for liquefiable soil and a total stress pressure independent plasticity model for clay, beam column elements for piles and structure, and interface springs that couple with the soil mesh for soil-structure interaction. The FE model was evaluated against recorded data for eight cases with same set of baseline parameters. Comparisons between analyses and experiments showed that the FE model was able to approximate the soil and structural responses and reproduce the lateral loads and bending moments on the piles reasonably well. © 2013, Earthquake Engineering Research Institute.

Published
2013

6. Static pushover analyses of pile groups in liquefied and laterally spreading ground in centrifuge tests

Author

Brandenberg, Scott J, Boulanger, R W, Kutter, Bruce L, and Chang, Dongdong

Subjects
Pile foundations, Pile caps, Earthquakes, Liquefaction, Centrifuge, Pile lateral loads, Soil deformation
Abstract

Monotonic, static beam on nonlinear Winkler foundation (BNWF) methods are used to analyze a suite of dynamic centrifuge model tests involving pile group foundations embedded in a mildly sloping soil profile that develops liquefaction-induced lateral spreading during earthquake shaking. A single set of recommended design guidelines was used for a baseline set of analyses. When lateral spreading demands were modeled by imposing free-field soil displacements to the free ends of the soil springs (BNWF_SD), bending moments were predicted within −8% to +69 16th to 84th percentile values and pile cap displacements were predicted within −6 to +38%, with the accuracy being similar for small, medium, and large motions. When lateral spreading demands were modeled by imposing limit pressures directly to the pile nodes (BNWF_LP), bending moments and cap displacements were greatly overpredicted for small and medium motions where the lateral spreading displacements were not large enough to mobilize limit pressures, and pile cap displacements were greatly underpredicted for large motions. The effects of various parameter relations and alternative design guidelines on the accuracy of the BNWF analyses were evaluated. Sources of bias and dispersion in the BNWF predictions and the issues of greatest importance to foundation performance are discussed. The results of these comparisons indicate that certain guidelines and assumptions that are common in engineering design can produce significantly conservative or unconservative BNWF predictions, whereas the guidelines recommended herein can produce reasonably accurate predictions.

Published
2007

7. Liquefaction-induced softening of load transfer between pile groups and laterally spreading crusts

Author

Brandenberg, Scott J, Boulanger, R W, Kutter, Bruce L, and Chang, Dongdong

Subjects
Pile foundations, Pile groups, Earthquakes, Liquefaction, Lateral loads, Deformation, Softening
Abstract

Laterally spreading nonliquefied crusts can exert large loads on pile foundations causing major damage to structures. While monotonic load tests of pile caps indicate that full passive resistance may be mobilized by displacements on the order of 1–7% of the pile cap height, dynamic centrifuge model tests show that much larger relative displacements may be required to mobilize the full passive load from a laterally spreading crust onto a pile group. The centrifuge models contained six-pile groups embedded in a gently sloping soil profile with a nonliquefied crust over liquefiable loose sand over dense sand. The nonliquefied crust layer spread downslope on top of the liquefied sand layer, and failed in the passive mode against the pile foundations. The dynamic trace of lateral load versus relative displacement between the “free-field” crust and pile cap is nonlinear and hysteretic, and depends on the cyclic mobility of the underlying liquefiable sand, ground motion characteristics, and cyclic degradation and cracking of the nonliquefied crust. Analytical models are derived to explain a mechanism by which liquefaction of the underlying sand layer causes the soil-to-pile-cap interaction stresses to be distributed through a larger zone of influence in the crust, thereby contributing to the softer load transfer behavior. The analytical models distinguish between structural loading and lateral spreading conditions. Load transfer relations obtained from the two analytical models reasonably envelope the responses observed in the centrifuge tests.

Published
2007

27. Two molecules newly identified by Mass Spectrometry in fermented cocoa beans have a strong impact on chocolate sensory quality

Author

Noémie Fayeulle, Anna Vallverdu Queralt, Jean Claude Boulet, Roger, J. M., Hue, C., Boulanger, R., Veronique Cheynier, Nicolas Sommerer, Sciences Pour l'Oenologie (SPO), Université Montpellier 1 (UM1)-Institut de Recherche pour le Développement (IRD [Nouvelle-Calédonie])-Institut National de la Recherche Agronomique (INRA)-Université de Montpellier (UM)-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro), Université Montpellier 1 (UM1)-Institut National de la Recherche Agronomique (INRA)-Université de Montpellier (UM)-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro), Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro), Institut National de la Recherche Agronomique (INRA)-Université de Montpellier (UM)-Université Montpellier 1 (UM1)-Institut de Recherche pour le Développement (IRD [Nouvelle-Calédonie])-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro), Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro), and Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Université Montpellier 1 (UM1)-Université de Montpellier (UM)-Institut National de la Recherche Agronomique (INRA)

Subjects
education, food and beverages, [SDV.BV]Life Sciences [q-bio]/Vegetal Biology, humanities, health care economics and organizations
Abstract

Two molecules newly identified by Mass Spectrometry in fermented cocoa beans have a strong impact on chocolate sensory quality. International Symposium on cocoa research

Published
2017

28. Fast discrimination of chocolates from mass spectrometry fingerprints of cocoa polyphenols

Author

Noémie Fayeulle, Chapel, S., Anna Vallverdu Queralt, Florine Grolet, Jean Claude Boulet, Roger, J. M., Hue, C., Boulanger, R., Veronique Cheynier, Nicolas Sommerer, Sciences Pour l'Oenologie (SPO), Institut National de la Recherche Agronomique (INRA)-Université de Montpellier (UM)-Université Montpellier 1 (UM1)-Institut de Recherche pour le Développement (IRD [Nouvelle-Calédonie])-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro), Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro), Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Université Montpellier 1 (UM1)-Université de Montpellier (UM)-Institut National de la Recherche Agronomique (INRA), Université Montpellier 1 (UM1)-Institut de Recherche pour le Développement (IRD [Nouvelle-Calédonie])-Institut National de la Recherche Agronomique (INRA)-Université de Montpellier (UM)-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro), Université Montpellier 1 (UM1)-Institut National de la Recherche Agronomique (INRA)-Université de Montpellier (UM)-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro), and Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)

Subjects
[SDV.BV]Life Sciences [q-bio]/Vegetal Biology
Abstract

Fast discrimination of chocolates from mass spectrometry fingerprints of cocoa polyphenols. SMMAP 2017 (Spectrométrie de Masse, Métabolomique et Analyse Protéomique)

Published
2017

32. Examination of the contaminants and performance of animals fed and bedded using de-inking paper sludge

Author

Beauchamp, Chantal Jeanne, Boulanger, R., Matte, J., Saint-Laurent, G., Beauchamp, Chantal Jeanne, Boulanger, R., Matte, J., and Saint-Laurent, G.

Abstract

In the noncereal-producing areas, there is not enough straw to supply the amount required for animal bedding. However, pulp and paper mills produce tons of wood fiber wastes, including de-inking paper sludge (DPS), in which most toxic compounds are at their detection limit. Among the detected compounds in DPS, aluminum, copper, and polycyclic aromatic hydrocarbons (PAHs) are present and were selected as model molecules. In this context, broilers were submitted to a diet containing 0, 5, and 10% of their ration as DPS. In addition, broilers and pigs were grown on de-inking paper sludge and wood shavings beddings. The presence of aluminum and copper were evaluated in blood and bones, whereas the presence of PAHs was evaluated in fat, liver, meat, and urine or blood of broilers and pigs. Animal performances were also investigated. DPS bedding did not increase aluminum or copper contents of blood or bones or PAHs in animal tissues. Animal performances and health were similar on DPS and wood shaving beddings. Using DPS as bedding material provides an integrated source of disposal of DPS and animal manure.

Published
2016

37. Cyclic softening of low plasticity clay and its effect on seismic foundation performance

Author

Chu, Daniel B, Stewart, Jonathan P, Boulanger, R W, and Lin, P. S.

Subjects
Cyclic softening, liquefaction, bearing capacity, case history
Abstract

During the 1999 Chi-Chi earthquake (Mw = 7.6), significant incidents of ground failure occurred in Wufeng, Taiwan, which experienced peak accelerations of about 0.7 g. We describe the results of field investigations and analyses of a small region within Wufeng along an E-W trending line 350 m long. The east end of the line has single-story structures for which there was no evidence of ground failure. The west end of the line had 3-6 story reinforced concrete structures that underwent differential settlement and foundation bearing failures. No ground failure was observed in the free-field. Surficial soils consist of low-plasticity silty clays that extend to 8-12 m depth in the damaged area (west side), and 3-10 m depth in the undamaged area (east side). A significant fraction of the foundation soils at the site are liquefaction-susceptible based on several recently proposed criteria, but the site performance cannot be explained by analysis in existing liquefaction frameworks. Accordingly, we use an alternative approach that accounts for the clayey nature of the foundation soils. Field and laboratory tests are used to evaluate the monotonic and cyclic shear resistance of the soil, which is compared to the cyclic demand placed on the soil by ground response and soil-structure interaction. Results of the analysis indicate a potential for cyclic softening and associated strength loss in foundation soils below the six-story buildings, which contributes to bearing capacity failures at the edges of the foundation. Similar analyses indicate high factors of safety in foundation soils below one-story buildings as well in the free field, which is consistent with the observed field performance.

Published
2008

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