Documents disponibles écrits par cet auteur

Corrosion rate evaluation and prediction for piles based on long-term field performance / Jeramy B. Decker in Journal of geotechnical and geoenvironmental engineering, Vol. 134 N°3 (Mars 2008) 

Public ISBD [article]  in Journal of geotechnical and geoenvironmental engineering > Vol. 134 N°3 (Mars 2008) . - pp. 341–351 Titre : Corrosion rate evaluation and prediction for piles based on long-term field performance Type de document : texte imprimé Auteurs : Jeramy B. Decker, Auteur ; Kyle M. Rollins, Auteur ; Jared C. Ellsworth, Auteur Année de publication : 2008 Article en page(s) : pp. 341–351 Note générale : Geotechnical and geoenvironmental engineering Langues : Anglais (eng) Mots-clés : Corrosion  Driven  piles  Infrastructure  Chlorides  Sulfates  Predictions Résumé : A study to evaluate corrosion rates was conducted using pile foundations abandoned during the reconstruction of I-15 through Salt Lake Valley, Utah. Corrosion rates were measured for 20 piles extracted from five sites after service lives of 34–38 years. Measurements were made of soil index properties, resistivity, pH, cation/anion concentrations, and water table elevation. The critical zone for corrosion was typically located within the groundwater fluctuation zone; but correlations with soil properties were generally poor. Despite low resistivity, average corrosion rates for pile caps in native soil were typically between 2 and 9μm∕year with a maximum of 19μm∕year and did not pose any structural integrity problems. Nevertheless, for abutment piles where chloride concentration was very high, the average pile corrosion rate increased to 13μm∕year within the embankment and the maximum corrosion rate was 48μm∕year in the underlying native soil. Based on data from this and previous studies, equations were developed to predict maximum corrosion loss for piles in nonaggressive soil as a function of time. En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%291090-0241%282008%29134%3A3%2834 [...] [article] Corrosion rate evaluation and prediction for piles based on long-term field performance [texte imprimé] / Jeramy B. Decker, Auteur ; Kyle M. Rollins, Auteur ; Jared C. Ellsworth, Auteur . - 2008 . - pp. 341–351. Geotechnical and geoenvironmental engineering Langues : Anglais (eng) in Journal of geotechnical and geoenvironmental engineering > Vol. 134 N°3 (Mars 2008) . - pp. 341–351 Mots-clés : Corrosion  Driven  piles  Infrastructure  Chlorides  Sulfates  Predictions Résumé : A study to evaluate corrosion rates was conducted using pile foundations abandoned during the reconstruction of I-15 through Salt Lake Valley, Utah. Corrosion rates were measured for 20 piles extracted from five sites after service lives of 34–38 years. Measurements were made of soil index properties, resistivity, pH, cation/anion concentrations, and water table elevation. The critical zone for corrosion was typically located within the groundwater fluctuation zone; but correlations with soil properties were generally poor. Despite low resistivity, average corrosion rates for pile caps in native soil were typically between 2 and 9μm∕year with a maximum of 19μm∕year and did not pose any structural integrity problems. Nevertheless, for abutment piles where chloride concentration was very high, the average pile corrosion rate increased to 13μm∕year within the embankment and the maximum corrosion rate was 48μm∕year in the underlying native soil. Based on data from this and previous studies, equations were developed to predict maximum corrosion loss for piles in nonaggressive soil as a function of time. En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%291090-0241%282008%29134%3A3%2834 [...]

Dynamic compaction of collapsible soils based on U.S. case histories / Kyle M. Rollins in Journal of geotechnical and geoenvironmental engineering, Vol. 136 N° 9 (Septembre 2010) 

Public ISBD [article]  in Journal of geotechnical and geoenvironmental engineering > Vol. 136 N° 9 (Septembre 2010) . - pp. 1178-1186 Titre : Dynamic compaction of collapsible soils based on U.S. case histories Type de document : texte imprimé Auteurs : Kyle M. Rollins, Auteur ; Jihyoung Kim, Auteur Année de publication : 2010 Article en page(s) : pp. 1178-1186 Note générale : Géotechnique Langues : Anglais (eng) Mots-clés : Collapsible  soils  Compaction  Dynamic  compaction  Soil  improvement  Vibration Index. décimale : 624.1 Infrastructures.Ouvrages en terre. Fondations. Tunnels Résumé : Dynamic compaction (DC) is an economical approach for mitigating the hazard posed by collapsible soils particularly when they are deeper than 3–4 m. In this paper, case histories are provided for 15 projects at 10 locations in the United States where collapsible soils were treated with DC. For each site the soil properties, compaction procedures, and subsequent improvement are summarized. Although cohesionless and low-plasticity collapsible soils were successfully compacted, clay layers in the profile appeared to absorb energy and severely reduced compaction effectiveness. Correlations are presented for estimating the maximum depth of improvement, the degree of improvement versus depth, the depth of craters, and the level of vibration based on measurements made at the various sites. The compactive energy per volume was typically higher than for noncollapsible soils because collapsible soils are usually loose but relatively stiff. The maximum depth of improvement was similar to that for noncollapsible soils; however, significant scatter was observed about the best-fit line. Improvement was nonuniform with nearly 80% of the total improvement occurring within the top 60% of the improvement zone. The crater depth was related to a number of factors besides the drop energy including the number of drops, drop spacing, and contact pressure. The peak particle velocities were typically lower than those for noncollapsible soils at shorter distances, but the vibrations attenuated more slowly with distance. DEWEY : 624.1 ISSN : 1090-0241 En ligne : http://ascelibrary.org/gto/resource/1/jggefk/v136/i9/p1178_s1?isAuthorized=no [article] Dynamic compaction of collapsible soils based on U.S. case histories [texte imprimé] / Kyle M. Rollins, Auteur ; Jihyoung Kim, Auteur . - 2010 . - pp. 1178-1186. Géotechnique Langues : Anglais (eng) in Journal of geotechnical and geoenvironmental engineering > Vol. 136 N° 9 (Septembre 2010) . - pp. 1178-1186 Mots-clés : Collapsible  soils  Compaction  Dynamic  compaction  Soil  improvement  Vibration Index. décimale : 624.1 Infrastructures.Ouvrages en terre. Fondations. Tunnels Résumé : Dynamic compaction (DC) is an economical approach for mitigating the hazard posed by collapsible soils particularly when they are deeper than 3–4 m. In this paper, case histories are provided for 15 projects at 10 locations in the United States where collapsible soils were treated with DC. For each site the soil properties, compaction procedures, and subsequent improvement are summarized. Although cohesionless and low-plasticity collapsible soils were successfully compacted, clay layers in the profile appeared to absorb energy and severely reduced compaction effectiveness. Correlations are presented for estimating the maximum depth of improvement, the degree of improvement versus depth, the depth of craters, and the level of vibration based on measurements made at the various sites. The compactive energy per volume was typically higher than for noncollapsible soils because collapsible soils are usually loose but relatively stiff. The maximum depth of improvement was similar to that for noncollapsible soils; however, significant scatter was observed about the best-fit line. Improvement was nonuniform with nearly 80% of the total improvement occurring within the top 60% of the improvement zone. The crater depth was related to a number of factors besides the drop energy including the number of drops, drop spacing, and contact pressure. The peak particle velocities were typically lower than those for noncollapsible soils at shorter distances, but the vibrations attenuated more slowly with distance. DEWEY : 624.1 ISSN : 1090-0241 En ligne : http://ascelibrary.org/gto/resource/1/jggefk/v136/i9/p1178_s1?isAuthorized=no

Increased lateral abutment resistance from gravel backfills of limited width / Kyle M. Rollins in Journal of geotechnical and geoenvironmental engineering, Vol. 136 N° 1 (Janvier 2010) 

Public ISBD [article]  in Journal of geotechnical and geoenvironmental engineering > Vol. 136 N° 1 (Janvier 2010) . - pp. 230-238 Titre : Increased lateral abutment resistance from gravel backfills of limited width Type de document : texte imprimé Auteurs : Kyle M. Rollins, Auteur ; Travis M. Gerber, Auteur ; Ku Hyun Kwon, Auteur Article en page(s) : pp. 230-238 Note générale : Géotechnique Langues : Anglais (eng) Mots-clés : Passive  pressure  Pile  caps  Gravel  Load  test  Dynamic  response Index. décimale : 624.1 Infrastructures.Ouvrages en terre. Fondations. Tunnels Résumé : Lateral pile cap tests were performed on a pile cap with three backfills to evaluate the static and dynamic behavior. One backfill consisted of loose silty sand while the other two consisted of 0.91- and 1.82-m-wide dense gravel zones between the pile cap and the loose silty sand. The 0.91- and 1.82-m-wide dense gravel zones increased the lateral resistance by 75 to 150% and 150 to 225%, respectively, relative to the loose silty sand backfill. Despite being thin relative to the overall shear length, the 0.92- and 1.82-m-wide gravel zones increase lateral resistance to approximately 54 and 78%, respectively, of the resistance that would be provided by a backfill entirely composed of dense gravel. The dynamic stiffness for the pile cap with the gravel zones decreased about 10% after 15 cycles of loading, while the damping ratio remained relatively constant with cycling. Dynamic stiffness increased by about 10 to 40% at higher deflections, while the damping ratio decreased from an initial value of about 0.30 to around 0.26 at higher deflections. DEWEY : 624.1 ISSN : 1090-0241 En ligne : http://ascelibrary.aip.org/vsearch/servlet/VerityServlet?KEY=JGGEFK&ONLINE=YES&s [...] [article] Increased lateral abutment resistance from gravel backfills of limited width [texte imprimé] / Kyle M. Rollins, Auteur ; Travis M. Gerber, Auteur ; Ku Hyun Kwon, Auteur . - pp. 230-238. Géotechnique Langues : Anglais (eng) in Journal of geotechnical and geoenvironmental engineering > Vol. 136 N° 1 (Janvier 2010) . - pp. 230-238 Mots-clés : Passive  pressure  Pile  caps  Gravel  Load  test  Dynamic  response Index. décimale : 624.1 Infrastructures.Ouvrages en terre. Fondations. Tunnels Résumé : Lateral pile cap tests were performed on a pile cap with three backfills to evaluate the static and dynamic behavior. One backfill consisted of loose silty sand while the other two consisted of 0.91- and 1.82-m-wide dense gravel zones between the pile cap and the loose silty sand. The 0.91- and 1.82-m-wide dense gravel zones increased the lateral resistance by 75 to 150% and 150 to 225%, respectively, relative to the loose silty sand backfill. Despite being thin relative to the overall shear length, the 0.92- and 1.82-m-wide gravel zones increase lateral resistance to approximately 54 and 78%, respectively, of the resistance that would be provided by a backfill entirely composed of dense gravel. The dynamic stiffness for the pile cap with the gravel zones decreased about 10% after 15 cycles of loading, while the damping ratio remained relatively constant with cycling. Dynamic stiffness increased by about 10 to 40% at higher deflections, while the damping ratio decreased from an initial value of about 0.30 to around 0.26 at higher deflections. DEWEY : 624.1 ISSN : 1090-0241 En ligne : http://ascelibrary.aip.org/vsearch/servlet/VerityServlet?KEY=JGGEFK&ONLINE=YES&s [...]

Reduction factor for the unloading point method at clay soil sites / Thomas J. Weaver in Journal of geotechnical and geoenvironmental engineering, Vol. 136 N° 4 (Avril 2010) 

Public ISBD [article]  in Journal of geotechnical and geoenvironmental engineering > Vol. 136 N° 4 (Avril 2010) . - pp. 643-646 Titre : Reduction factor for the unloading point method at clay soil sites Type de document : texte imprimé Auteurs : Thomas J. Weaver, Auteur ; Kyle M. Rollins, Auteur Année de publication : 2010 Article en page(s) : pp. 643-646 Note générale : Géotechnique Langues : Anglais (eng) Mots-clés : Rapid  Load  Test  Pile  Foundation  Statnamic  Fundex  Unloading  point  method  Clay  Rate  effects Index. décimale : 624.1 Infrastructures.Ouvrages en terre. Fondations. Tunnels Résumé : Full-scale testing can be an integral component of quality control/quality assurance for projects involving construction of deep foundations. Rapid load tests are being used in the deep foundation industry as a method for assessing the axial static behavior of deep foundations. Since rapid load tests involve dynamics, inertial and damping forces must be considered in analyzing measured pile response to estimate the static pile response. The unloading point method (UPM) is typically used for this purpose. Generally considered a consequence of load rate effects in clays, results from the UPM must be further modified by a reduction factor to obtain a reasonable estimate of the static pile response. A reduction factor of 0.65 applied to the UPM for clay soil sites has been recommended by others. However, a review and analysis of readily available literature reporting static and rapid pile load test results at sites predominantly consisting of clay soils indicate that an average reduction factor of 0.47 is more appropriate. Rapid load testing should be used judiciously. When using the UPM to estimate static pile capacity from rapid load tests in clay, static load tests should be performed to validate the reduction factor used to interpret rapid load tests. DEWEY : 624.1 ISSN : 1090-0241 En ligne : http://ascelibrary.org/gto/resource/1/jggefk/v136/i4/p643_s1?isAuthorized=no [article] Reduction factor for the unloading point method at clay soil sites [texte imprimé] / Thomas J. Weaver, Auteur ; Kyle M. Rollins, Auteur . - 2010 . - pp. 643-646. Géotechnique Langues : Anglais (eng) in Journal of geotechnical and geoenvironmental engineering > Vol. 136 N° 4 (Avril 2010) . - pp. 643-646 Mots-clés : Rapid  Load  Test  Pile  Foundation  Statnamic  Fundex  Unloading  point  method  Clay  Rate  effects Index. décimale : 624.1 Infrastructures.Ouvrages en terre. Fondations. Tunnels Résumé : Full-scale testing can be an integral component of quality control/quality assurance for projects involving construction of deep foundations. Rapid load tests are being used in the deep foundation industry as a method for assessing the axial static behavior of deep foundations. Since rapid load tests involve dynamics, inertial and damping forces must be considered in analyzing measured pile response to estimate the static pile response. The unloading point method (UPM) is typically used for this purpose. Generally considered a consequence of load rate effects in clays, results from the UPM must be further modified by a reduction factor to obtain a reasonable estimate of the static pile response. A reduction factor of 0.65 applied to the UPM for clay soil sites has been recommended by others. However, a review and analysis of readily available literature reporting static and rapid pile load test results at sites predominantly consisting of clay soils indicate that an average reduction factor of 0.47 is more appropriate. Rapid load testing should be used judiciously. When using the UPM to estimate static pile capacity from rapid load tests in clay, static load tests should be performed to validate the reduction factor used to interpret rapid load tests. DEWEY : 624.1 ISSN : 1090-0241 En ligne : http://ascelibrary.org/gto/resource/1/jggefk/v136/i4/p643_s1?isAuthorized=no