Current Issue : October - December Volume : 2018 Issue Number : 4 Articles : 5 Articles
The stability of earthworks (cuttings, embankments, dikes) and natural slopes\nis a problem that is of concern to geotechnicians, both practitioners and researchers.\nThe disorders generated by breaking the slopes are usually spectacular,\noften destructive and sometimes murderers. Many methods of calculating\nstability have been proposed. These are differentiated by the assumptions\naccepted by their authors (methods of calculation in equilibrium limit,\nmethods of calculation at break, deformation calculation methods) and the\nease of their implementation (calculations using charts, automatic calculations\nusing software), but they all agree to define an overall factor of safety according\nto which the stability of the studied slope is considered to be insured or\ncompromised, or by safety factor spartial effects on the one hand, applied\nstresses and, on the other hand, the mechanical properties soil. Various embankment\nstrengthening techniques have been developed. They are differentiated\nby the process of their realization, their cost and their durability. The\nmain objective of this study is to present the problems of both natural and artificial\nslope stability on construction projects. In this regard, special emphasis\nis given to the sensitivity of the calculation model input parameters (soil, load),\nwhich should contribute to raising awareness about this issue, as a prerequisite\nto make the right decisions and optimal technical solutions in this area....
The question of how to give meaning to the concept of sustainability in architectural design\npractices is highly contested today. Although architects, engineers, clients, politicians, and others seem\nto agree that sustainability must be addressed, behind this apparent consensus many ambiguities,\ncontradictions, and open questions emerge. Opinions largely vary on how to define the sustainability\nchallenges that architectural design is to respond to, how to align the various stakeholders involved,\nwhich scales and elements to consider, and how to transform these questions into design strategies,\nspatial configurations, and materiality of buildings. These practices cannot be confined merely\nto technological problem-solving as they essentially mesh a range of cognitive, social, cultural,\nand material elements. This article draws on the interdisciplinary field of Science and Technology\nStudies (STS) to set out the transferable analytical framework of ââ?¬Ë?translationââ?¬â?¢ through which to\nexplain how the concept of sustainability is continuously transformed within contingent, complex,\nand dynamic architectural design practices as buildings materialize. The framework of translation is\nparticularly well adapted to unpack claims, make them more accountable, and thereby support the\nlarger project of sustainability....
Under earthquake action, the reinforced concrete structure at the edge of the CAP1400 nuclear power plant foundation slab will\nbe uplifted. In order to determine the seismic performance of this structure, a 1 : 12 scale shaking table test model was fabricated\nusing gypsum as simulated concrete in order to meet scaled design requirements. By testing this model, the seismic response of\nthe structure with consideration of the foundation uplift was obtained. Numerical analyses of the test model and the prototype\nstructure were conducted to gain a better understanding of the structural seismic performance. When subjected to earthquakes,\nthe foundation slab of the nuclear power plant experiences a slight degree of uplift but remains in the elastic stage due to the weight\nof the structure above, which provides an antioverturning moment. The numerical simulation is in general agreement with the test\nresults, suggesting numerical simulations could be accurately employed in place of physical tests. The superstructure displacement\nresponse was found not to affect the safety of adjacent structures, and the seismic performance of the structure was shown to meet\nthe relevant design requirements, demonstrating that this approach tomodelling can serve as a design basis for theCAP1400 nuclear\npower demonstration project....
The seismic behavior of asymmetric structures with a flexible diaphragmwas studied by conducting inelastic dynamic time-history\nanalyses. Asymmetric structures with different configurations of mass, stiffness, and strength centers, in combination with a wide\nrange of diaphragm flexibility, were evaluated. The behavior of structures was studied by considering three aspects: (1) effect of\nstructural asymmetry on diaphragms deformation; (2) effect of diaphragm flexibility on demands of the lateral load-resisting\nelements; (3) optimum configuration of mass, stiffness, and strength centers to limit important engineering demand parameters\nin asymmetric structures with a flexible diaphragm. The results showed that the shear-dominant deformation of diaphragms is\nsensitive to both structure asymmetry specifications and the degree of diaphragm flexibility; therefore, it can be used for the\nqualitative classification of the seismic behavior of structures. Also, the center of strength in structures with flexible diaphragm\nis more important relative to the stiffness center and has a significant effect on engineering demands at all levels of diaphragm\nflexibility. Moreover, it was found that a suitable configuration of centers in torsionally stiff structures depends on the degree of\ndiaphragm flexibility, in addition to the intensity of earthquakes (structure yield level) and selected engineering demand parameter....
Plastic limit analysis is a significant application for structural design and failure prediction, implying that the potential bearing\ncapacity of material can be fully considered. Meanwhile, the failure process of structures usually occurs in the deformation of the\nplastic stage. Hence, it is important to investigate the mechanical properties of structures in the plastic state through proper\nmechanical models and principles. In this paper, the analytical stress expression and formulas for computing plastic limit load\nhave been deduced based on the unified strength theory. Additionally, the relationships between plastic limit load of the shaft\nlining and the strength differential (SD) of structural material, the geometrical characteristic (R0/R) and the intermediate principal\nshear stress (b) have been discussed. Finally, the method of the plastic limit load is adopted for the safety evaluation of the shaft\nlining through a practical case....
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