نشریه مهندسی عمران فردوسی
سال سی و ششم شماره 3 (پاییز 1402)

The type of land use in each traffic area zone (TAZ) is the most important factor determining the number of vehicles, geometric and traffic characteristics in that zone. Any factor in the urban environment that causes congestion and attraction of vehicles at certain times increases the probability of an accident in that area.In this study, in order to investigate the effect of the share of the types of uses in each of the traffic areas of Shiraz city on the probability of an accident, a two-step method including the identification of the types of uses influencing the occurrence of accidents as well as spatial effects between independent variables and accident data in space Kernel density estimate (KDE) methods have also been used in order to find the suitable bandwidth for searching observations, geographically weighted regression (GWR) and geographically weighted Poisson regression (GWPR) in order to investigate the spatial effects of the contribution of land use types on the occurrence Accident is used .The results of the study have shown that among the mentioned models, the local GWPR model has a better performance than the global Poisson model and the local GWR model based on validation criteria. Also, the presence of residential, commercial, barren and abandoned uses and the mixing of residential and non-residential use have the greatest impact on They have accidents. Examining the spatial effects of land use types in each of the traffic areas in this study can be very important in order to carry out safety measures.

This research was carried out in Takht-e-Gonbad open pit copper mine in Kerman province, located in 80 km northeast of Sirjan. According to structural geology, this area is located in the Urumieh-Dokhtar Magmatic Arc. This mine is currently in the early years of mineral extraction. The 69 exploration boreholes have been drilled in rock units around the mine pit in which the flush return percentage during drilling were also collected. It is necessary to identify areas with higher permeability in the rock units to design the dewatering plan in the future, so that, geostatistics and simulation methods were used to analyze the flush return. The results of the preliminary statistics show the percentage of the flush return increases with depth. Investigating the spatial continuity of this variable based on the variograms and the spherical model shows that its spatial continuity is about 252 meters, with dominant elongation at the east-west direction. Furthermore, the northeast and southwest portions of the mine are observed to have the largest permeability using the geostatistical simulations by the Gaussian method.

In this research, the effect of the elliptical web reduction, the effect of the radial flange reduction and also the effect of the use of stiffener, on the behavior of beam, on the behavior of connection and on the performance of steel moment frame is studied. By using Finite-Elements Method and 3D elements in ABAQUS, the nonlinear-static analyses of the frame under cyclic loading are carried out and the Von-Mises criterion is checked. The results show that in the beam with no reductions, maximum stresses and strains occur in the web. By reducing the web section of the beam, maximum stresses and strains are transferred to the location of the reduced section. The ratio of maximum strength to the strength at the final step of loading, and also, the value of dissipated energy, show that, in comparison with the connections with radial-shaped reductions, the connections with elliptical-shaped reductions have less strength degradation and more ductility.

The use of structural elements such as piles are considered as an effective solution in improving the overall performance of an embankment system in terms of stability and settlement control. In recent years using helical piles has been considered due to their proper performance. This research presents a numerical investigation to compare the performance of embankments rested on concrete and helical piles. A 3D finite element models are developed separately in ABAQUS software for embankments based on helical and concrete piles while the length and diameter of their pile shafts are the same. The model was validated via comparing the obtained numerical results with the field and laboratory measurements (observation). The results show that the helical piles have significantly reduced the settlement in the embankments and the soft foundation soil and controlled lateral embankment displacement. Also, the distribution of axial force along the embedment depth of the pile indicates that the helical pile has higher bearing capacity than the concrete pile and behaves frictionally. The presence of the cap on the helical pile was also examined and the results show that it causes adequate control of the settlement in the embankment system and increases the bearing capacity of the piles. In addition, adding the blade to the pile body at different distances does not have a significant effect on improving the performance of the pile-supported embankment system while it could lead to embankment settlement and lower load transmission.

The use of dredged-marine-sand and seawater for concrete production is practically more justified in marine environments due to the primary sources of these materials. Also, it is very crucial to examine the durability parameters of concrete structures in marine environments, especially in tidal conditions, because in these area, consecutive dry/wet cycles, temperature and humidity gradients over time, intensify carbonation and diffusion of conductive ions, therefore physical and chemical deterioration accelerated accordingly. The aim of this research is to investigate the effect of metakaolin, silica fume, and slag on the mechanical properties and microstructure Seawater-seasand concrete in tidal conditions. The results showed that the use of seawater and sand in concrete, due to the presence of chloride ions as well as the filling of voids by ettringite caused by the sulfates attacks, led to the improvement of mechanical properties in the early ages, but after that, a significant drop was occurred. Due to the high source of SiO2 and its high reactivity, silica fume accelerated the consumption of calcium hydroxide, prevented carbonation progress, and formed a dense calcium-silicate-hydrate gel in the microstructure of Seawater-seasand-concrete, and in the presence of magnesium sulfate, better than slag and metakaolin, prevented the formation of ettringite and therefore, propagation of pores and microcracks.

Policy making is one of the suitable approaches in acquiring city developing goals and providing better services for citizens. This research was accomplished by the objective of policy making in the city services in municipality by using mixed approach. This research is an applied research. The research is accomplished by utilizing mixed approach in both quantity and quality areas. In quantity area, data was gathered by questionnaire tool. The research population consisted of 10 persons of expert managers of municipality. Dimensions and components of screening and selecting were done by Fuzzy Delphi and utilizing Fuzzy DEMATEL method, their relationship was determined then the pattern was designed, and finally by using Fuzzy Analytical Network Process weighed and prioritized. The findings of the quality part indicated that the pattern included five dimensions including: “environmental”, “economical”, “cultural”, “contextual”, and “operational” dimensions orderly and 20 components. The findings of quantity part and Fuzzy DEMATEL indicated that there is a kind of relationship between dimensions, so that the “environmental”, “economical”, “cultural”, “contextual”, “operational” dimensions have mutual effects on each others, orderly. The weighing findings also showed that the “operational” dimension had the most weight, and the components “human capacity”, “evaluation”, and “implementation” acquired the first, second and third importance, orderly. So, it is proposed that the managers of municipality concentrate on human resources to implement the proposed pattern for enabling the human resources in interoffice part and have coordination with superiors in out of organization part.