dorsal/arxiv
View SchemaSeismic motion in urban sites consisting of blocks in welded contact with a soft layer overlying a hard half space: II. large and infinite number of identical equispaced blocks
| Authors | Armand Wirgin, Jean-Philippe Groby |
|---|---|
| Categories | |
| ArXiv ID | physics/0610277 |
| URL | https://arxiv.org/abs/physics/0610277 |
Abstract
We address the problem of the response to a seismic wave of an urban site consisting of a large and infinite number ($N\_{b}$) of identical, equispaced blocks overlying a soft layer underlain by a hard substratum. The results of the theoretical analysis, appealing to a space-frequency mode-matching (MM) technique, are compared to those obtained by a space-time finite element (FE) method. The two methods are shown to give rise to much the same prediction of seismic response for $N\_{b}=10$. The MM technique is also applied to the case $N\_{b}=\infty$, notably to reveal the structure and natural frequencies of the vibration modes of the urban site. The mechanism of the interaction between blocks and the ground, as well as that of the collective effects of the blocks, are studied. It is shown that the presence of a large number of blocks modifies the seismic disturbance in a manner which evokes, and may partially account for, what was observed during many earthquakes in Mexico City. Disturbances at a much smaller level, induced by a small number of blocks are studied in the companion paper.
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"abstract": "We address the problem of the response to a seismic wave of an urban site\nconsisting of a large and infinite number ($N\\_{b}$) of identical, equispaced\nblocks overlying a soft layer underlain by a hard substratum. The results of\nthe theoretical analysis, appealing to a space-frequency mode-matching (MM)\ntechnique, are compared to those obtained by a space-time finite element (FE)\nmethod. The two methods are shown to give rise to much the same prediction of\nseismic response for $N\\_{b}=10$. The MM technique is also applied to the case\n$N\\_{b}=\\infty$, notably to reveal the structure and natural frequencies of the\nvibration modes of the urban site. The mechanism of the interaction between\nblocks and the ground, as well as that of the collective effects of the blocks,\nare studied. It is shown that the presence of a large number of blocks modifies\nthe seismic disturbance in a manner which evokes, and may partially account\nfor, what was observed during many earthquakes in Mexico City. Disturbances at\na much smaller level, induced by a small number of blocks are studied in the\ncompanion paper.",
"arxiv_id": "physics/0610277",
"authors": [
"Armand Wirgin",
"Jean-Philippe Groby"
],
"categories": [
"physics.geo-ph",
"physics.class-ph"
],
"title": "Seismic motion in urban sites consisting of blocks in welded contact with a soft layer overlying a hard half space: II. large and infinite number of identical equispaced blocks",
"url": "https://arxiv.org/abs/physics/0610277"
},
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