Current Issue : July - September Volume : 2016 Issue Number : 3 Articles : 4 Articles
A digital elevation model (DEM) is an important spatial input for automatic extraction of topographic parameters for the soil and\nwater assessment tool (SWAT). The objective of this study was to investigate the impact of DEM resolution (from 5 to 90m) on the\ndelineation process of a SWAT model with two types of watershed characteristics (flat area and mountain area) and three sizes of\nwatershed area (about 20,000, 200,000, and 1,500,000 hectares). The results showed that the total lengths of the streamline, main\nchannel slope, watershed area, and area slope were significantly different when using the DEM datasets to delineate. Delineation\nusing the SRTMDEM(90 m), ASTERDEM(30 m), and LDDDEM(5m) for all watershed characteristics showed that the watershed\nsizes and shapes obtained were only slightly different, whereas the area slopes obtained were significantly different.The total lengths\nof the generated streams increased when the resolution of the DEM used was higher.The stream slopes obtained using the small\narea sizes were insignificant, whereas the slopes obtained using the large area sizes were significantly different. This suggests that\nwater resource model users should use the ASTER DEMas opposed to a finer resolution DEMfor model input to save time for the\nmodel calibration and validation....
The paper presents a new method for designing railway route in the direction change area adapted to the Mobile Satellite\nMeasurements technique. The method may be particularly useful in the situations when both tangents cannot be connected in\nan elementary way using a circular arc with transition curves. Thus, the only solution would be the application of two circular\narcs of opposite curvature signs, that is, the use of an inverse curve. It has been assumed that the design of the geometrical layout\nwill take place within an adequate local coordinate system. The solution of the design problem takes advantage of a mathematical\nnotation and concentrates on the determination of universal equations describing the entire geometrical layout. This is a sequential\noperation involving successive parts of the mentioned layout. This universal algorithm can be easily applied to the computer software\nwhich will allow generating, in an automatic way, other geometrical layouts. Then, the choice of the most beneficial variant from\nthe point of obtained trains velocities while minimizing the track axis offsets will be held using the optimization techniques. The\ncurrent designing methods do not provide such opportunities.The presented method has been illustrated by appropriate calculation\nexamples....
Plain concrete and steel fiber reinforced concrete (SFRC) cylinder specimens are modeled in the finite element (FE) platform of\nANSYS 10.0 and validated with the experimental results and failure patterns. Experimental investigations are conducted to study\nthe increase in compressive and tensile capacity of cylindrical specimens made of stone and brick concrete and SFRC. Satisfactory\ncompressive and tensile capacity improvement is observed by adding steel fibers of 1.5% volumetric ratio. A total of 8 numbers of\ncylinder specimens are cast and tested in 1000 kNcapacity digital universal testingmachine (UTM)and alsomodeled inANSYS.The\nenhancement of compressive strength and splitting tensile strength of SFRC specimen is achieved up to 17% and 146%, respectively,\ncompared to respective plain concrete specimen. Results gathered from finite element analyses are validated with the experimental\ntest results by identifying as well as optimizing the controlling parameters to make FE models. Modulus of elasticity, Poisson�s\nratio, stress-strain behavior, tensile strength, density, and shear transfer coefficients for open and closed cracks are found to be the\nmain governing parameters for successful model of plain concrete and SFRC in FE platform. After proper evaluation and logical\noptimization of these parameters by extensive analyses, finite element (FE) models showed a good correlation with the experimental\nresults....
This study intends to find out the correlation between the cover depth and the bond characteristics\nof UHPC through pull-out tests of UHPC specimens with different cover depths and bond tests\nof rebar using flexural members. In this experimental study, specimens are fabricated with the\nlap-splice length as test variable in relation with the calculation of the lap-splice length for 180-\nMPa UHPC. Moreover, specimens are also fabricated with the cover depth as test variable to evaluate\nthe effect of the cover depth on the UHPC flexural members. The load-displacement curves\nare analyzed for each of these test variables to compute the lap-splice length proposed in the\nK-UHPC structural design guideline and to evaluate the influence of the cover depth on the flexural\nmembers. As a result, the stability of the structural behavior can be significantly enhanced by increasing\nslightly the cover depth specification of the current UHPC Structure Design Guideline\nfrom the maximum value between 1.5 times of rebar diameter and 20 mm to the maximum value\nbetween 1.5 times of rebar diameter and 25 mm....
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