Famille et fécondité à Shiraz (1996)

Ce rapport présente les résultats préliminaires d'une enquête effectuée au cours de l'année 1996, sur la famille, la fécondité et les pratiques contraceptives dans la ville de Shiraz, capitale administrative de la province du Fars, située au sud-ouest de l'Iran. Une des raisons majeures de l'enquête de Shiraz est d'étudier les changements radicaux qu'a connu la société iranienne, et plus spécialement leurs effets éventuels sur les tendances démographiques du pays. A cet égard, la baisse de la fécondité très sensible observée depuis quelques années et l'adoption récente par l'Iran d'un programme de planification familiale dynamique ont été accueillies avec intérêt par la communauté internationale des démographes et des spécialistes de la planification familiale. Les progrès réalisés en Iran dans le domaine de la planification familiale et de la régulation des naissances sont venus remettre en question les idées reçues concernant la prétendue incompatibilité entre programmes de modernisation et tradition islamique. En fait, un des objectifs de l'enquête était précisément d'explorer comment avait pu se produire une baisse de fécondité, rapide et forte, dans la société iranienne post-révolutionnaire

Numerical Analysis of Shallow Foundations with Varying Loading and Soil Conditions

The load–deformation relationship under the footing is essential for foundation design. Shallow foundations are subjected to changes in hydrological conditions such as rainfall and drought, affecting their saturation level and conditions. The actual load–settlement response for design and reconstructions is determined experimentally, numerically, or utilizing both approaches. Ssettlement computation is performed through large-scale physical modeling or extensive laboratory testing. It is expensive, labor intensive, and time consuming. This study is carried out to determine the effect of different saturation degrees and loading conditions on settlement shallow foundations using numerical modeling in Plaxis 2D, Bentley Systems, Exton, Pennsylvania, US. Plastic was used for dry soil calculation, while fully coupled flow deformation was used for partially saturated soil. Pore pressure and deformation changes were computed in fully coupled deformation. The Mohr–Columb model was used in the simulation, and model parameters were calculated from experimental results. The study results show that the degree of saturation is more critical to soil settlement than loading conditions. When a 200 KPa load was applied at the center of the footing, settlement was recored as 28.81 mm, which was less than 42.96 mm in the case of the full-depth shale layer; therefore, settlement was reduced by 30% in the underlying limestone rock layer. Regarding settlement under various degrees of saturation (DOS), settlment is increased by an increased degree of saturation, which increases pore pressure and decreases the shear strength of the soil. Settlement was observed as 0.69 mm at 0% saturation, 1.93 mm at 40% saturation, 2.21 mm at 50% saturation, 2.77 mm at 70% saturation, and 2.84 mm at 90% saturation of soil

Experimental and analytical investigation of improved behavior of existing steel connections by adding self-centering capabilities

This study presents a new post-tensioning configuration for enhancing the seismic performance of existing steel bolted connections. The nonlinear behavior of the proposed post-tensioned connection was investigated through experimental and analytical programs. Different post-tensioning strand configurations were installed on top-and-seat angle connections with different strand length, strand number, and initial post-tensioning force. Data from the tested post-tensioned connections showed a significant improvement in the nonlinear behavior when compared to their non-post-tensioned counterparts. This improvement was achieved by increasing the overall stiffness and strength in addition to providing self-centering capabilities that could limit the residual drifts for the retrofitted moment-resisting frames after a strong earthquake. An analytical representation of the proposed connection is presented and modified considering the effect of the strand relaxation. The derived analytical equation accurately represented the response of the post-tensioned beam-to-column connection in terms of the moment-rotation relationship and it could be used for the analysis and design of post-tensioned connections subjected to large deformations