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A three-dimensional mathematical hydrodynamic model associated with surface wave radiation by a floating rectangular box-type structure due to heave, sway, and roll motions in finite water depth is investigated based on small amplitude water wave theory and linear structural response. The analytical expressions for the radiation potentials, wave forces, and hydrodynamic coefficients are presented based on matched eigenfunction expansion method (MEFEM). The correctness of the analytical results of wave forces is compared with the construction of a numerical model using the open-source boundary element method code NEMOH. In addition, the present result is compared with the existing published experimental results available in the literature. The effects of the different design parameters on the floating box-type rectangular structure are studied by analyzing the vertical wave force, horizontal wave force, torque, added mass, and damping coefficients due to the heave, sway, and roll motions, and the comparison analysis between the forces is also analyzed in detail. Further, the effect of reflection and transmission coefficients by varying the structural width and drafts are analyzed. [ABSTRACT FROM AUTHOR]

The use of “ductile seismic frames,” whose proper seismic behavior largely depends upon construction details and specific design rules, may do not always lead to effective seismic resistant structures, as dramatically denounced by the famous Chinese artist Ai Weiwei in his artwork Straight. The artwork (96 t of undulating metal bars that were salvaged from schools destroyed by the 2008 Sichuan, China earthquake, where over 5,000 students were killed) is a clear denounce against the corruption yielding to shoddy construction methods. The issue of safe constructions against natural hazards appears even more important in developing countries where, in most cases, building structures are realized by non-expert workers, or even by simple “people from the street,” who does not have any technical knowledge on construction techniques and seismic engineering. In this paper, a brief history from the first frame structures to the more efficient wall-based structures is provided within Earthquake Engineering perspectives. The superior structural properties of box-type wall structures with respect to conventional frame structures envisage a change of paradigm from actual “ductility-based” Earthquake Engineering (centered on frame structures) toward 100% safe buildings through a “strength-based” design exploiting the use of box-type wall-based structures.

The dynamic response of lined tunnels with a uniform box-type cross-section buried into elastic half-space to explosion seismic waves is studied by employing the matrix force method and treating the structure as a connecting rod system interacting with foundation. The main equations for dynamic analyzing of the hyperstatic structure are deduced and solving method is proposed. A case study is implemented to investigate the influence of span-height ratio of the structure and foundation-structure wave impedance ratio. The results are presented in nondimensional form to obtain a clear physical understanding of the dynamic response of structure. It is shown that the dynamic response of box-type structure can be significantly influenced by the span-height ratio as well as the foundation conditions. Since nondimensional parameters are adopted, the results are independent of dimension and can extend to structures with different size and working conditions. This study provides an analysis method and new insights into the dynamic response of underground box-type structures. [ABSTRACT FROM AUTHOR]

Laterite blocks are used for construction of masonry walls since ages in the South-western coastal areas of India. The south-west coastal areas of India lie in zone III of seismic zonation map of Indian code IS 1893-2002. In spite of the fact that laterite is the most favored masonry material in these regions of India, the structural Performance of laterite masonry has not been systematically investigated. Again there are no previous studies addressing, in detail, the seismic performance of laterite masonry buildings. Now that these areas are becoming more and more important from point of view of trade and commerce, there is a need for a detailed research on the seismic response of laterite masonry structures located in these areas. The present paper reports the results of such a study of the seismic response of box-type laterite masonry structures. Time history analysis of these structures under El-Centro acceleration has been performed using commercial finite element software ANSYS. Effect of 'containment reinforcement' on the seismic response of box type laterite masonry structures has been evaluated. [ABSTRACT FROM AUTHOR]

This work deals with the homogenization of the nonstationary heat conduction which takes place in a binary three-dimensional medium consisting of an ambiental phase having conductivity of unity order and a set of highly conductive thin walls crossing orthogonally and periodically. This situation covers in fact three types of microstructures, usually called: box-type (or honeycomb), gridwork and layered. The study is based on the energetic procedure of homogenization associated to a control-zone method, specific to the geometry of the microstructure and to the singularity of the conductivity coefficients. In the present case the main result is the system that governs the asymptotic behaviour of the temperature distribution in this binary medium. It displays a significant increase of the conductivity due to the superconductive thin walls, revealing their seemingly paradoxal behaviour of having an everlasting action on the environment, in spite of an obvious vanishing volume. Moreover, the dependence of this behaviour with respect to the relative thicknesses of the walls can be detailed.. [ABSTRACT FROM PUBLISHER]