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91.
Rigoberto G. Sanabria Castro Sandra M. C. Malta Abimael F. D. Loula Luiz Landau 《Computational Geosciences》2002,5(4):301-330
A finite element formulation is proposed to approximate a nonlinear system of partial differential equations, composed by an elliptic subsystem for the pressure–velocity and a transport equation (convection–diffusion) for the concentration, which models the incompressible miscible displacement of one fluid by another in a rigid porous media. The pressure is approximated by the classical Galerkin method and the velocity is calculated by a post-processing technique. Then, the concentration is obtained by a Galerkin/least-squares space–time (GLS/ST) finite element method. A numerical analysis is developed for the concentration approximation. Then, stability, convergence and numerical results are presented confirming the a priori error estimates. 相似文献
92.
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94.
Masao Komazawa Hitoshi Morikawa Kajuro Nakamura Junpei Akamatsu Keiichi Nishimura Sumio Sawada Ayfer Erken Akin Onalp 《Soil Dynamics and Earthquake Engineering》2002,22(9-12):829-836
The 1999 Kocaeli earthquake brought serious damage to downtown of Adapazari. To study why strong motions were generated at the town, a bedrock structure was investigated on the basis of Bouguer gravity anomaly, and SPAC and H/V analyses of microseisms. It was revealed that, the basin consists of three narrow depressions of bedrock with very steep edges, extending in E–W or NE–SW directions along the North Anatolia faults, and the depth to bedrock reaches 1000 m or more. Downtown of Adapazari is located 1–2 km apart from the basin-edge. It is considered that, the specific configuration of bedrock amplifies ground motions at the downtown area by focusing of seismic waves and/or interference between incident S-waves and surface-waves secondarily generated at the basin-edge. Studying 3D bedrock structure is an urgent issue for microzoning an urban area in a sedimentary basin. 相似文献
95.
桥梁限位器抗震设计方法研究 总被引:4,自引:0,他引:4
本文建立了两跨简支梁桥和五跨多跨刚架桥两结构模型,针对限位器的种类、刚度、强度、安装位置,输入地震动等进行了大量工况下的数值模拟研究。研究表明限位器与柱(框架)的刚度比在0.5-2之间较优。将现有的限位器设计方法应用于两算例结构,对现有限位器设计方法进行了比较研究。 相似文献
96.
南京地区新近沉积土的动剪切模量和阻尼比的初步研究 总被引:9,自引:1,他引:9
本文通过对南京地区两个工程场地漫滩相成因的砂土和淤泥质粉粘土与粉砂互层土的自振动柱试验结果进行分析,探讨了围压对剪切模量G及阻力比λ的影响,通过与Seed和Idriss建议的砂土G/Gmax-γ和λ-γ曲线变化范围的对比,认为不能简单地把淤泥质粉质粘土与粉砂层土当作砂土或粉质粘土对待。 相似文献
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98.
Shin Okamoto Nagahide Kani Masahiko Higashino Norihide Koshika Masayuki Kimizuka Mitsumasa Midorikawa Masanori Iiba 《地震工程与工程振动(英文版)》2002,1(2):213-225
The Building Standard Law of Japan and related Enforcement Order and Notifications have been substantially revised since the
year 2000 to introduce a performance-based regulatory and deregulation system for building control systems. Up to then, time-history
analyses were mandatory for isolated buildings and had to be specially approved by the Minster of the Ministry of Construction
(MOC). Simplified design procedures based on the equivalent linear method for seismically isolated buildings have been issued
as “Notification 2009 — Structural calculation procedure for buildings with seismic isolation” from MOC, and are now integrated
into the Ministry of Land, Infrastructure, and Transportation (MLIT). Along with Notification 2009, “Notification 1446 of
year 2000 — Standard for specifications and test methods for seismic isolation devices” was also issued. Buildings with heights
equal to or less than 60m and that are designed according to these Notifications, including base isolated buildings, only
need approval from local building officials, and no longer require the special approval of the Minister of MLIT. This paper
summarizes: 1) some statistics related to buildings with seismic isolation completed up to the end of 2001; 2) simplified
design procedures required by Notification 2009 of year 2000; and 3) performance of seismic isolation devices required by
Notification 1446 of year 2000. 相似文献
99.
100.
Geographies of Displacement: The Karenni and The Shan Across The Myanmar-Thailand Border 总被引:1,自引:0,他引:1
First, central to our analysis is the argument that human movement within and across borders fundamentally challenges the view of geopolitics based upon fixed territorial states, inter-state relations, national identities and citizenship; indeed the whole idea of "national geographic". Using the examples of the Karen and Shan peoples, we explore the processes and patterns of forced relocation, displacement and migration in the border regions of Myanmar and Thailand. Our main concern is with forced displacement as a result of political and ethnic conflict; specifically, how the Burmese military regime's desire for "national unity" within Myanmar's "national space" has influenced the militarily inspired displacements of hundreds of thousands of villagers and civilians within the border zones inhabited mostly by so-called "national minorities". We examine the particular problems of the so-called "internally displaced persons" within "national" boundaries compared with the "refugees" and "undocumented migrants" who make it across "international" space into Thailand. We illustrate the ways displaced people are represented by state agencies and the media as "threats" and "transgressors". We consider some of the "long term" aspects of the displacement problem along the Myanmar-Thai border and the vital contribution geographers can make to the study of displacement. 相似文献