Shaking‐table tests of a full‐scale single‐story masonry veneer wood‐frame structure     

Hussein O. Okail  P. Benson Shing  William M. McGinley  Richard E. Klingner  Seongwoo Jo  David I. McLean 《地震工程与结构动力学》2011,40(5):509-530

This paper presents the findings of shaking‐table experiments conducted to examine the seismic performance of a full‐scale, one‐story, wood‐framed structure with masonry veneer. The structure was designed and constructed in accordance with current U.S. code provisions. The veneer was attached to the wood backing with two kinds of metal anchors, corrugated ties fastened with 8d nails and rigid ties fastened with #8 screws. The tests have shown that the use of nails to fasten veneer anchors to the wood studs is highly unreliable due to the high variation of the nail extraction capacity, which can be influenced by the moisture content of the wood. Other than this, both the wood frame and the masonry veneer performed well under severe ground motions far exceeding a design level earthquake for Seismic Design Category D. Good performance was observed for the rigid veneer ties, which were attached to the wood studs with screws. The results have shown that the veneer walls parallel to the direction of shaking helped to restrain the motion of the wood structure and therefore should not be simply treated as added mass. The detailing of wood roof diaphragms requires special attention in consideration of the out‐of‐plane inertia force of the veneer that can be transmitted through the top plate of the wood‐stud wall to the rim joist. Copyright © 2010 John Wiley & Sons, Ltd.  相似文献   

Gypsum and dolomite biomineralization in endoevaporitic microbial niche,EMISAL, Fayium,Egypt     

Mohamed W. Ali-Bik  Hussein I. M. Metwally  Mohamed G. Kamel  Ashraf M. A. Wali 《Environmental Earth Sciences》2011,62(1):151-159

Biogenic gypsum in the form of microbialite and potential domal stromatolite as well as endoevaporitic dolomite are deposited in a perennial saline basin characterized by microbial bloom. Deposition environment, mode of occurrence, and microscopic investigation including SEM of these precipitates are discussed in conjunction with XRD, XRF, and FTIR data. Combined effects of salinity gradient and the wind action on the maturity of gypsum outcrop are evident. A characteristic multi-color vertical gypsum profile reflects steep gradient of oxi-anoxic microenvironments and encodes diverse seasonal microbial communities. Direct impact of microbial signature in gypsum crystal habit is conspicuous. Endoevaporitic authigenic dolomite is recorded in specific horizons in interstices of selenite layers.  相似文献   

Salinization and Deterioration of Groundwater Quality by Nitrate and Fluoride in the Chittur Block,Palakkad, Kerala     

E. Shaji  J.J. Gómez-Alday  S. Hussein  T. R. Deepu  Y. Anilkumar 《Journal of the Geological Society of India》2018,92(3):337-345

Chittur block represents a mid-land region of Palakkad district, Kerala and the block differs from the rest of the blocks in its climate and availability of groundwater. About 75% of the people depend on agriculture for their livelihood. Results showed that groundwater salinity levels (up to 1,963 mg/L TDS),fluoride (up to 6.3 mg/L) and nitrate (up to 141 mg/L) contents have increased significantly in tandem with the increase in groundwater abstraction. Before human intervention the chemical weathering of gneisses and granites was the main process impinging on the chemical signature of groundwater. The initial chemical equilibrium conditions change with increasing groundwater withdrawal rates and fertilizer input, in a milieu of lower natural groundwater recharge. The appearance of higher levels of bicarbonate, linked to denitrification processes, and the decrease in calcium, due to calcite precipitation, can lead to increased content of sodium and fluoride in groundwater. In this scenario the use of groundwater resources for human consumption and agriculture represents a public health risk if water management actions do not change the trend in water use in the near future. The potential loss of fertile soil by groundwater salinization must also be considered when planning sustainable policies in a region with over dependence on groundwater resources.  相似文献   

CDFSIM: Efficient Stochastic Simulation Through Decomposition of Cumulative Distribution Functions of Transformed Spatial Patterns   总被引：1，自引：1，他引：0  

Hussein Mustapha  Snehamoy Chatterjee  Roussos Dimitrakopoulos 《Mathematical Geosciences》2014,46(1):95-123

Simulation of categorical and continuous variables is performed using a new pattern-based simulation method founded upon coding spatial patterns in one dimension. The method consists of, first, using a spatial template to extract information in the form of patterns from a training image. Patterns are grouped into a pattern database and, then, mapped to one dimension. Cumulative distribution functions of the one-dimensional patterns are built. Patterns are then classified by decomposing the cumulative distribution functions, and calculating class or cluster prototypes. During the simulation process, a conditioning data event is compared to the class prototype, and a pattern is randomly drawn from the best matched class. Several examples are presented so as to assess the performance of the proposed method, including conditional and unconditional simulations of categorical and continuous data sets. Results show that the proposed method is efficient and very well performing in both two and three dimensions. Comparison of the proposed method to the filtersim algorithm suggests that it is better at reproducing the multi-point configurations and main characteristics of the reference images, while less sensitive to the number of classes and spatial templates used in the simulations.  相似文献   

Integrated geophysical study to explore the groundwater in the tectonic plain between Wadi El Mahash and Wadi Um Markhah,Southwest Sinai,Egypt     

Adel D. M. Kotb  Galal H. G. Hussein  Mahmoud A. ElHefnawy 《Arabian Journal of Geosciences》2014,7(6):2179-2197

South Sinai Governorate acts as one of the most vital regions in Egypt for its location and natural resources. This governorate has a special economic importance to increase the national income due to its tourism expansion and petroleum. The fresh water is transferred from Cairo through pipelines to cover the demands of local inhabitants in the north Sinai governorate and the capital city of south Sinai governorate. The groundwater exploration and exploitation in this area have a great importance to cover the need of water for the different activities (tourism, petroleum, and agriculture) and to achieve a maximum development in this region. Therefore, the present study deals with using the different geophysical exploration techniques (magnetic, geoelectrical resistivity and shallow refraction seismic) to detect the groundwater aquifer or aquifers in the area between latitudes 27°52′ and 28°05′?N and longitudes 33°55′ and 34°05′?E. in southwestern Sinai—Egypt. The main results of these tools are the maximum depth to the basement surface 180 m and structure elements which affected on this area are represented by a number of normal faults have a trends (NNW–SSE and ENE–WSW) making two grabens isolated by one horst. Tariff Sandstone bed recorded as water-bearing formation and the basement ridge gates in the gulf direction are not capable to pass the ground water from the study area to the Gulf of Suez. Finally, the best locations for drilling groundwater wells were selected from the decision map which generated by using the GIS technique.  相似文献   

Cumulative impact mapping: Advances,relevance and limitations to marine management and conservation,using Canada's Pacific waters as a case study     

Natalie C. Ban  Hussein M. Alidina  Jeff A. Ardron 《Marine Policy》2010

Analysis of cumulative human impacts in the marine environment is still in its infancy but developing rapidly. In this study, existing approaches were expanded upon, aiming for a realistic consideration of cumulative impacts at a regional scale. Thirty-eight human activities were considered, with each broken down according to stressor types and a range of spatial influences. To add to the policy relevance, existing stressors within and outside of conservation areas were compared. Results indicate the entire continental shelf of Canada's Pacific marine waters is affected by multiple human activities at some level. Commercial fishing, land-based activities and marine transportation accounted for 57.0%, 19.1%, and 17.7% of total cumulative impacts, respectively. Surprisingly, most areas with conservation designations contained higher impact scores than the mean values of their corresponding ecoregions. Despite recent advances in mapping cumulative impacts, many limitations remain. Nonetheless, preliminary analyses such as these can provide information relevant to precautionary management and conservation efforts.  相似文献   

Subsidence and Sinkhole Hazard Assessment in the Southern Dead Sea Area,Jordan   总被引：1，自引：0，他引：1  

Damien?ClossonEmail author  Najib Abou?Karaki  Yann?Klinger  Musa Jad?Hussein 《Pure and Applied Geophysics》2005,162(2):221-248

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An integrated geophysical study for inferring the subsurface setting of water-bearing aquifers: case study at Wadi al-Dawasir area,Saudi Arabia     

Abdulsalam Al Asmari  Saad Mogren  Aref Lashin  Mohamed Hussein  Fouzan Al Fouzan 《Environmental Earth Sciences》2016,75(12):1028

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Fast wavelet-based stochastic simulation using training images     

Snehamoy Chatterjee  Hussein Mustapha  Roussos Dimitrakopoulos 《Computational Geosciences》2016,20(3):399-420

Spatial uncertainty modelling is a complex and challenging job for orebody modelling in mining, reservoir characterization in petroleum, and contamination modelling in air and water. Stochastic simulation algorithms are popular methods for such modelling. In this paper, discrete wavelet transformation (DWT)-based multiple point simulation algorithm for continuous variable is proposed that handles multi-scale spatial characteristics in datasets and training images. The DWT of a training image provides multi-scale high-frequency wavelet images and one low-frequency scaling image at the coarsest scale. The simulation of the proposed approach is performed on the frequency (wavelet) domain where the scaling image and wavelet images across the scale are simulated jointly. The inverse DWT reconstructs simulated realizations of an attribute of interest in the space domain. An automatic scale-selection algorithm using dominant mode difference is applied for the selection of the optimal scale of wavelet decomposition. The proposed algorithm reduces the computational time required for simulating large domain as compared to spatial domain multi-point simulation algorithm. The algorithm is tested with an exhaustive dataset using conditional and unconditional simulation in two- and three-dimensional fluvial reservoir and mining blasted rock data. The realizations generated by the proposed algorithm perform well and reproduce the statistics of the training image. The study conducted comparing the spatial domain filtersim multiple-point simulation algorithm suggests that the proposed algorithm generates equally good realizations at lower computational cost.  相似文献   

Invariant shape solutions of the spinning three craft Coulomb tether problem     

Islam I. Hussein  Hanspeter Schaub 《Celestial Mechanics and Dynamical Astronomy》2006,96(2):137-157

In this paper we study shape-preserving formations of three spacecraft, where the formation keeping forces arise from the electric charges deposed on each craft. Inspired by Lagrange’s 3-body problem, the general conditions that guarantee preservation of the geometric shape of the electrically charged formation are derived. While the classical collinear configuration is a solution to the problem, the equilateral triangle configuration is found to only occur with unbounded relative motion. The three collinear spacecraft problem is analyzed and the possible solutions are categorized based on the spacecraft mass–charge ratio. Precise statements on the number of solutions associated with each category are provided. Finally, a methodology is proposed to study boundedness of the collinear solution that is inspired by past understanding and results for the 3-body problem. Given the initial position and the velocity vectors of each craft along with the charges, analytical solutions are provided describing the resulting relative motion.  相似文献