Three dimensional numerical simulation of residential building on shrink–swell soils in response to climatic conditions          下载免费PDF全文

Xiong Zhang  Jean‐Louis Briaud 《国际地质力学数值与分析法杂志》2015,39(13):1369-1409

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   

Crack Extension in Hydraulic Fracturing of Shale Cores Using Viscous Oil,Water, and Liquid Carbon Dioxide     

Ziad Bennour  Tsuyoshi Ishida  Yuya Nagaya  Youqing Chen  Yoshitaka Nara  Qu Chen  Kotaro Sekine  Yu Nagano 《Rock Mechanics and Rock Engineering》2015,48(4):1463-1473

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Soil property variation mapping through data mining of soil category maps          下载免费PDF全文

Fei Du  A‐Xing Zhu  Lawrence Band  Jing Liu 《水文研究》2015,29(11):2491-2503

Spatial information on soil properties is an important input to hydrological models. In current hydrological modelling practices, soil property information is often derived from soil category maps by the linking method in which a representative soil property value is linked to each soil polygon. Limited by the area‐class nature of soil category maps, the derived soil property variation is discontinuous and less detailed than high resolution digital terrain or remote sensing data. This research proposed dmSoil, a data‐mining‐based approach to derive continuous and spatially detailed soil property information from soil category maps. First, the soil–environment relationships are extracted through data mining of a soil map. The similarity of the soil at each location to different soil types in the soil map is then estimated using the mined relationships. Prediction of soil property values at each location is made by combining the similarities of the soil at that location to different soil types and the representative soil property values of these soil types. The new approach was applied in the Raffelson Watershed and Pleasant Valley in the Driftless Area of Wisconsin, United States to map soil A horizon texture (in both areas) and depth to soil C horizon (in Pleasant Valley). The property maps from the dmSoil approach capture the spatial gradation and details of soil properties better than those from the linking method. The new approach also shows consistent accuracy improvement at validation points. In addition to the improved performances, the inputs for the dmSoil approach are easy to prepare, and the approach itself is simple to deploy. It provides an effective way to derive better soil property information from soil category maps for hydrological modelling. Copyright © 2014 John Wiley & Sons, Ltd.  相似文献   

Geotechnical Feasibility Analysis of Compressed Air Energy Storage (CAES) in Bedded Salt Formations: a Case Study in Huai’an City,China     

Guimin Zhang  Yinping Li  Jaak J. K. Daemen  Chunhe Yang  Yu Wu  Kai Zhang  Yanlong Chen 《Rock Mechanics and Rock Engineering》2015,48(5):2111-2127

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Pre‐Alpine discordant granitic dikes in the metamorphic core of the Betic Cordillera: tectonic implications     

Antonio Sánchez‐Navas  Antonio García‐Casco  Agustín Martín‐Algarra 《地学学报》2014,26(6):477-486

Pegmatite dikes bearing andalusite crosscut foliation S₂ in Alpujarride gneisses and schists. Post‐S₂ andalusite is transposed by a foliation S₃, defined by fibrolite, which affects the dikes. The dikes represent highly differentiated granitic magmas with low REE and Zr contents and a positive Eu anomaly. U‐Pb SHRIMP dating of magmatic zircons provided Pan‐African ages (cores) and late Variscan ages (rims). However, U‐rich rims also provided metamorphic Alpine ages, supporting a polyorogenic tectonometamorphic history for pre‐Mesozoic Alpujarride rocks.  相似文献   

A tree‐ring width based drought reconstruction for southeastern China: links to Pacific Ocean climate variability          下载免费PDF全文

Feng Chen  Shulong Yu  Yujiang Yuan  Huiqin Wang  Mary Gagen 《Boreas: An International Journal of Quaternary Research》2016,45(2):335-346

We present a drought reconstruction for southeastern China based on a tree‐ring width chronology of Cryptomeria fortunei developed from two sampling sites in central Fujian. A reconstruction of July–February drought variability, spanning AD 1855–2011, was developed by calibrating total tree‐ring width data with the self‐calibrating Palmer drought severity index (scPDSI). The reconstruction was verified against an independent data set, and accounts for 36% of the actual scPDSI variance during the period 1955–2011. Relatively dry intervals were reconstructed between AD 1859–1880, 1899–1911, 1927–1933, 1946–1959, 1964–1970 and 1987–1997. Relatively wet conditions prevailed during 1855–1858, 1881–1898, 1912–1926, 1934–1945, 1960–1963, 1971–1986 and 1998–2011. Comparisons between our scPDSI reconstruction and a moisture‐sensitive tree‐ring width record from Vietnam revealed consistencies between the two data sets, suggesting similar drought regimes. Spectral peaks of 2.2–6.4 years may be indicative of El Niño‐Southern Oscillation (ENSO) activity, as also suggested by the significant correlations with sea surface temperatures (SSTs) in the eastern equatorial and southeastern Pacific Ocean and an extreme event analysis. The analysis of links between our scPDSI reconstruction and the large‐scale regional climatic variation shows that there is a relationship between regional drought variation and East Asian summer monsoon (EASM) intensity.  相似文献   

Does stress transmission in forelands depend on structural style? Distinctive stress magnitudes during Sevier thin‐skinned and Laramide thick‐skinned layer‐parallel shortening in the Bighorn Basin (USA) revealed by stylolite and calcite twinning paleopiezometry     

Nicolas Beaudoin  Olivier Lacombe  Marie‐Elonore David  Daniel Koehn 《地学学报》2020,32(3):225-233

The Sheep Mountain‐Little Sheep Mountain Anticlines, Bighorn Basin (USA) formed as basement‐cored Laramide structures in the formerly undeformed foreland of the thin‐skinned Sevier orogen. We take advantage of the well‐constrained microstructural network there to reconstruct differential stress magnitudes that prevailed during both Sevier and Laramide layer‐parallel shortening (LPS), before the onset of large‐scale folding. Differential stress magnitudes determined from tectonic stylolites are compared and combined to previous stress estimates from calcite twinning paleopiezometry in the same formations. During stress loading related to LPS, differential stress magnitudes transmitted from the distant Sevier thin‐skinned orogen into the sedimentary cover of the Bighorn basin (11–43 MPa) are higher than the differential stress magnitudes accompanying the early stage of LPS related to the thick‐skinned Laramide deformation (2–19 MPa). This study illustrates that the tectonic style of an orogen affects the transmission of early orogenic stress into the stable continental interior.  相似文献   

Full and ideal mixing behavior between Zr–Wd (K2ZrSi3O9) and Ti–Wd (K2TiSi3O9): evidences from mineral chemistry,X-ray diffraction pattern and Raman spectrum     

Linlin Chang  Xi Liu  Chunming Wu  Xiaoyang Liu  Guowu Li 《Physics and Chemistry of Minerals》2015,42(3):223-234

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Polygonal grain‐based distinct element modeling for mechanical behavior of brittle rock          下载免费PDF全文

J.‐W. Park  C. Park  J.‐W. Song  E.‐S. Park  J.‐J. Song 《国际地质力学数值与分析法杂志》2017,41(6):880-898

The microstructure of rock was numerically reproduced by a polygonal grain‐based model, and its mechanical behavior was examined by performing the uniaxial compression test and Brazilian tests via the Universal Distinct Element Code. The numerical results of the model demonstrated good agreement with the experimental results obtained with rock specimens in terms of the stress–strain behavior, strength characteristics, and brittle fracture phenomenon. An encouraging result is that the grain‐based model‐Universal Distinct Element Code model can reproduce a low ratio of tensile to compressive strength of 1/20 to 1/10 without the need for an additional process. This finding is ascribed to the fact that the geometrical features of polygons can effectively capture the effects of angularity, finite rotation, and interlocking of grains that exist in reality. A numerical methodology to monitor the evolution of micro‐cracks was developed, which enabled us to examine the progressive process of the failure and distinguish the contribution of tensile cracking to the process from that of shear cracking. From the observations of the micro‐cracking process in reference to the stress–strain relation, crack initiation stress, and crack damage stress, it can be concluded that the failure process of the model closely resembles the microscopic observations of rock. We also carried out a parametric study to examine the relationships between the microscopic properties and the macroscopic behavior of the model. Depending on the micro‐properties, the model exhibited a variety of responses to the external load in terms of the strength and deformation characteristics, the evolution of micro‐cracks, and the post‐peak behavior. Copyright © 2016 John Wiley & Sons, Ltd.  相似文献   

The influence of coupled physical swelling and chemical reactions on deformable geomaterials     

Yue Ma  Xiao‐Hui Chen  Lee J. Hosking  Hai‐Sui Yu  Hywel R. Thomas  Simon Norris 《国际地质力学数值与分析法杂志》2021,45(1):64-82

Coupled thermo‐hydro‐mechanical‐chemical modelling has attracted attention in past decades due to many contemporary geotechnical engineering applications (e.g., waste disposal, carbon capture and storage). However, molecular‐scale interactions within geomaterials (e.g., swelling and dissolution/precipitation) have a significant influence on the mechanical behaviour, yet are rarely incorporated into existing Thermal‐Hydro‐Mechanical‐Chemical (THMC) frameworks. This paper presents a new coupled hydro‐mechanical‐chemical constitutive model to bridge molecular‐scale interactions with macro‐physical deformation by combining the swelling and dissolution/precipitation through an extension of the new mixture‐coupling theory. Entropy analysis of the geomaterial system provides dissipation energy, and Helmholtz free energy gives the relationship between solids and fluids. Numerical simulation is used to compare with the selected recognized models, which demonstrates that the swelling and dissolution/precipitation processes may have a significant influence on the mechanical deformation of the geomaterials.  相似文献