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根据福建沿海湄洲湾、江阴、可门3条支线港口铁路的工程地质条件、水文地质特征,综合分析认为在工程施工过程中局部出现不良地质现象,主要有软土、块石填土、不均匀地基、地下水的腐蚀性等.总结在施工过程中因工程地质问题导致的设计变更及处理措施. 相似文献
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Three dimensional numerical simulation of residential building on shrink–swell soils in response to climatic conditions
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Shrink–swell soils can cause distresses in buildings, and every year, the economic loss associated with this problem is huge. This paper presents a comprehensive system for simulating the soil–foundation–building system and its response to daily weather conditions. Weather data include rainfall, solar radiation, air temperature, relative humidity, and wind speed, all of which are readily available from a local weather station or the Internet. These data are used to determine simulation flux boundary conditions. Different methods are proposed to simulate different boundary conditions: bare soil, trees, and vegetation. A coupled hydro‐mechanical stress analysis is used to simulate the volume change of shrink–swell soils due to both mechanical stress and water content variations. Coupled hydro‐mechanical stress‐jointed elements are used to simulate the interaction between the soil and the slab, and general shell elements are used to simulate structural behavior. All the models are combined into one finite element program to predict the entire system's behavior. This paper first described the theory for the simulations. A site in Arlington, Texas, is then selected to demonstrate the application of the proposed system. Simulation results are shown, and a comparison between measured and predicted movements for four footings in Arlington, Texas, over a 2‐year period is presented. Finally, a three‐dimensional simulation is made for a virtual residential building on shrink–swell soils to identify the influence of various factors. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
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The objective of this paper is to describe the lessons learned and actions that have been taken related to the seismic design
of bridge structures after the Chi-Chi, Taiwan earthquake. Much variable near-fault ground motion data was collected from
the rupture of Chelungpu fault during the Chi-Chi earthquake, allowing the seismic response of bridge structures subjected
to these near-fault ground motions to be carefully examined. To study the near-fault ground motion effect on bridge seismic
design codes, a two-level seismic design of bridge structures was developed and implemented. This design code reflects the
near-fault factors in the seismic design forces. Finally, a risk assessment methodology, based on bridge vulnerability, is
also developed to assist in decisions for reducing seismic risk due to failure of bridges.
Director of Center for Research on Earthquake Engineering.
Supported by: the Science Council, Chinese Taipei, under grant no. SC 90-2211-E-002-028. 相似文献
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联合国教科文组织创意城市网络“设计之都”神户市在日本率先明确将城市设计运用于创意城市建设,提出涵盖外观形状和颜色设计以及计划与制度体系、意图与思维方式的“大设计”概念,并在此基础上制定了以建设优裕的创意城市为目标的城市发展规划,提出城市发展的方向是建设“高质量生活”,以安全、安心、健康为基础,以多样性交流与融合创造新价值为特征的创意城市.“设计之都”是创意城市建设的步骤之一,其特征是充分利用神户的优势资源,进行空间的设计、经济的设计和文化的设计. 相似文献
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Ian Muehlenhaus 《制图学和地理信息科学》2013,40(5):401-414
Persuasive maps are ubiquitous in society, yet cartographers have largely neglected to conduct serious, holistic research on them. Persuasive maps represent a form of visual communication that differs markedly from scientific geovisualization. First, many of these maps' communicative goals are anathema to those of scientific representation. Second, many persuasive maps ignore and defy established cartographic conventions. This article argues two things. First, the cartographic discipline can gain insight about how maps communicate information from the longitudinal and holistic analysis of persuasive maps. By comparing the differences and similarities of persuasive maps to scientific geovisualizations, researchers can begin to understand how persuasive maps communicate differently than scientific ones. Second, breaking persuasive maps down into composite parts may make it possible to identify persuasive map norms (i.e., methods of design that are embraced by producers of persuasive maps). The results of a content analysis of 256 persuasive maps are discussed. The article concludes that it may be possible to take the most statistically significant results from this study to begin identifying different rhetorical styles of persuasive maps. 相似文献
19.
C. Baccigalupi L. Bedini C. Burigana G. De Zotti A. Farusi D. Maino M. Maris F. Perrotta E. Salerno L. Toffolatti A. Tonazzini 《Monthly notices of the Royal Astronomical Society》2000,318(3):769-780
We implement an independent component analysis (ICA) algorithm to separate signals of different origin in sky maps at several frequencies. Owing to its self-organizing capability, it works without prior assumptions on either the frequency dependence or the angular power spectrum of the various signals; rather, it learns directly from the input data how to identify the statistically independent components, on the assumption that all but, at most, one of the components have non-Gaussian distributions.
We have applied the ICA algorithm to simulated patches of the sky at the four frequencies (30, 44, 70 and 100 GHz) used by the Low Frequency Instrument of the European Space Agency's Planck satellite. Simulations include the cosmic microwave background (CMB), the synchrotron and thermal dust emissions, and extragalactic radio sources. The effects of the angular response functions of the detectors and of instrumental noise have been ignored in this first exploratory study. The ICA algorithm reconstructs the spatial distribution of each component with rms errors of about 1 per cent for the CMB, and 10 per cent for the much weaker Galactic components. Radio sources are almost completely recovered down to a flux limit corresponding to ≃0.7 σCMB , where σ CMB is the rms level of the CMB fluctuations. The signal recovered has equal quality on all scales larger than the pixel size. In addition, we show that for the strongest components (CMB and radio sources) the frequency scaling is recovered with per cent precision. Thus, algorithms of the type presented here appear to be very promising tools for component separation. On the other hand, we have been dealing here with a highly idealized situation. Work to include instrumental noise, the effect of different resolving powers at different frequencies and a more complete and realistic characterization of astrophysical foregrounds is in progress. 相似文献
We have applied the ICA algorithm to simulated patches of the sky at the four frequencies (30, 44, 70 and 100 GHz) used by the Low Frequency Instrument of the European Space Agency's Planck satellite. Simulations include the cosmic microwave background (CMB), the synchrotron and thermal dust emissions, and extragalactic radio sources. The effects of the angular response functions of the detectors and of instrumental noise have been ignored in this first exploratory study. The ICA algorithm reconstructs the spatial distribution of each component with rms errors of about 1 per cent for the CMB, and 10 per cent for the much weaker Galactic components. Radio sources are almost completely recovered down to a flux limit corresponding to ≃0.7 σ
20.
A collaborative structural analysis (CSA) system is developed, which is capable of performing highly sophisticated structural analyses utilizing beneficial features of existing individual structural analysis programs. In the system, the global equations of motion for the overall structural system are formulated in the host program. Some substructures, whose behaviors are relatively simple, are directly solved in the host program, whereas those having complex behavior are analyzed by the station programs. A time‐consuming static condensation procedure is needed for the substructures analyzed by the station programs if adopting an implicit integration scheme. The operator splitting (OS) method, which does not require tangential stiffness, can be used to improve the system efficiency. To this end, a hybrid formulation of the Newmark‐β and OS methods is proposed, and a CSA scheme based on the hybrid formulation is developed. In the CSA system adopting the hybrid formulation, the degrees of freedom whose tangential stiffness are unavailable are formulated by the OS method, whereas the rest are still formulated by the commonly used Newmark‐β method. Using the system, analyses of a three‐story‐braced steel moment‐resisting frame are conducted. In the analyses, the column bases are analyzed using the commercial finite element method software ABAQUS, and the remaining structural elements are analyzed using a frame analysis program called NETLYS. Results suggest that the hybrid formulation is very effective for the CSA system. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献