Documents disponibles écrits par cet auteur

Seismic response of geocell retaining walls / Ling, Hoe I. in Journal of geotechnical and geoenvironmental engineering, Vol. 135 N° 4 (Avril 2009) 

Public ISBD [article]  in Journal of geotechnical and geoenvironmental engineering > Vol. 135 N° 4 (Avril 2009) . - pp. 515–524 Titre : Seismic response of geocell retaining walls : experimental studies Type de document : texte imprimé Auteurs : Ling, Hoe I., Auteur ; Leshchinsky, Dov, Auteur ; Jui-Pin Wang, Auteur Année de publication : 2009 Article en page(s) : pp. 515–524 Note générale : Geotechnical and geoenvironmental engineering Langues : Anglais (eng) Mots-clés : Seismic  effects  Earthquakes  Retaining  walls  Experimentation Résumé : This paper summarizes the seismic response of five large-scale retaining walls having a geocell facing. The walls were 2.8m high and the backfill and foundation soil were a fine sand compacted to 90% standard Proctor density (relative density of 55%). The first two walls were of the same geometry, with a tapered facing made of geocells each of height 20cm , one infilled with gravel and the other with sand. In Wall 3, a facing of depth 60cm was constructed while the backfill sand was reinforced with a polyester geogrid. Wall 4 was similar to Wall 3 except that the backfill was reinforced with several geocell layers. Wall 5 had thin geocell layers of 5cm height as reinforcements in order to improve the performance compared with Wall 4. The walls were subjected to the scaled horizontal and vertical motions as recorded during the 1995 Kobe earthquake, 4.5m/s2 (450gal) and 9.0m/s2 (900gal) maximum horizontal accelerations in the first and second excitations, respectively. In an attempt to induce failure, and therefore, to investigate the failure mechanism, Walls 3–5 were subjected to a third shaking in which the horizontal accelerations were scaled to 12.0m/s2 (1,200gal) . The walls were fully instrumented with accelerometers, laser displacement transducers, force transducers, and strain gauges. All five walls performed satisfactorily under the simulated earthquake motions. An improved wall performance was seen with the geocells acting as reinforcement layers. The study showed that geocells can be used successfully to form gravity walls as well as reinforcement layers even when subjected to a very high seismic load beyond that of the Kobe earthquake. En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%291090-0241%282009%29135%3A4%2851 [...] [article] Seismic response of geocell retaining walls : experimental studies [texte imprimé] / Ling, Hoe I., Auteur ; Leshchinsky, Dov, Auteur ; Jui-Pin Wang, Auteur . - 2009 . - pp. 515–524. Geotechnical and geoenvironmental engineering Langues : Anglais (eng) in Journal of geotechnical and geoenvironmental engineering > Vol. 135 N° 4 (Avril 2009) . - pp. 515–524 Mots-clés : Seismic  effects  Earthquakes  Retaining  walls  Experimentation Résumé : This paper summarizes the seismic response of five large-scale retaining walls having a geocell facing. The walls were 2.8m high and the backfill and foundation soil were a fine sand compacted to 90% standard Proctor density (relative density of 55%). The first two walls were of the same geometry, with a tapered facing made of geocells each of height 20cm , one infilled with gravel and the other with sand. In Wall 3, a facing of depth 60cm was constructed while the backfill sand was reinforced with a polyester geogrid. Wall 4 was similar to Wall 3 except that the backfill was reinforced with several geocell layers. Wall 5 had thin geocell layers of 5cm height as reinforcements in order to improve the performance compared with Wall 4. The walls were subjected to the scaled horizontal and vertical motions as recorded during the 1995 Kobe earthquake, 4.5m/s2 (450gal) and 9.0m/s2 (900gal) maximum horizontal accelerations in the first and second excitations, respectively. In an attempt to induce failure, and therefore, to investigate the failure mechanism, Walls 3–5 were subjected to a third shaking in which the horizontal accelerations were scaled to 12.0m/s2 (1,200gal) . The walls were fully instrumented with accelerometers, laser displacement transducers, force transducers, and strain gauges. All five walls performed satisfactorily under the simulated earthquake motions. An improved wall performance was seen with the geocells acting as reinforcement layers. The study showed that geocells can be used successfully to form gravity walls as well as reinforcement layers even when subjected to a very high seismic load beyond that of the Kobe earthquake. En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%291090-0241%282009%29135%3A4%2851 [...]

Stress deformation and fluid pressure of bone specimens under cyclic loading / Ling, Hoe I. in Journal of engineering mechanics, Vol. 135 N° 5 (Mai 2009) 

Public ISBD [article]  in Journal of engineering mechanics > Vol. 135 N° 5 (Mai 2009) . - pp. 375-381 Titre : Stress deformation and fluid pressure of bone specimens under cyclic loading Type de document : texte imprimé Auteurs : Ling, Hoe I., Auteur ; Emi Ling, Auteur ; Jui-Pin Wang, Auteur Article en page(s) : pp. 375-381 Note générale : Mécanique appliquée Langues : Anglais (eng) Mots-clés : Human  factors  Biological  properties  Mechanical  properties  Deformation  Cyclic  loads. Résumé : Cyclic loading has been known to induce fluid flow and thus mechanotransduction in bones. In the past, four-point bending tests have been used exclusively in studying fluid flow in bones. In order to better understand the mechanism of deformation and fluid flow under loading, compression tests were done on trabecular bone specimens under drained and undrained conditions. In the drained tests, the volume change was observed, whereas in the undrained tests, excess pore fluid pressure was measured. Cyclic loading tests were conducted in addition to monotonic loading tests to observe the permanent volume change or excess pore fluid pressure with loading cycles. A fast loading rate gave a sharp rise in the excess fluid pressure compared to a slow loading rate. The strength and stiffness of the specimens appeared to deteriorate with an increased speed of loadings, but there was no appreciable difference between the results obtained from drained and undrained tests. The drained and undrained tests as described allowed a better understanding of bone behavior under loadings for a coupled stress-flow analysis. DEWEY : 620.1 ISSN : 0733-9399 En ligne : http://ascelibrary.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JENMDT000 [...] [article] Stress deformation and fluid pressure of bone specimens under cyclic loading [texte imprimé] / Ling, Hoe I., Auteur ; Emi Ling, Auteur ; Jui-Pin Wang, Auteur . - pp. 375-381. Mécanique appliquée Langues : Anglais (eng) in Journal of engineering mechanics > Vol. 135 N° 5 (Mai 2009) . - pp. 375-381 Mots-clés : Human  factors  Biological  properties  Mechanical  properties  Deformation  Cyclic  loads. Résumé : Cyclic loading has been known to induce fluid flow and thus mechanotransduction in bones. In the past, four-point bending tests have been used exclusively in studying fluid flow in bones. In order to better understand the mechanism of deformation and fluid flow under loading, compression tests were done on trabecular bone specimens under drained and undrained conditions. In the drained tests, the volume change was observed, whereas in the undrained tests, excess pore fluid pressure was measured. Cyclic loading tests were conducted in addition to monotonic loading tests to observe the permanent volume change or excess pore fluid pressure with loading cycles. A fast loading rate gave a sharp rise in the excess fluid pressure compared to a slow loading rate. The strength and stiffness of the specimens appeared to deteriorate with an increased speed of loadings, but there was no appreciable difference between the results obtained from drained and undrained tests. The drained and undrained tests as described allowed a better understanding of bone behavior under loadings for a coupled stress-flow analysis. DEWEY : 620.1 ISSN : 0733-9399 En ligne : http://ascelibrary.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JENMDT000 [...]