نشریه مهندسی عمران و محیط زیست دانشگاه تبریز
سال پنجاهم شماره 3 (پیاپی 100، پاییز 1399)

The term “Specific Surface Area” (SSA) refers to the area per unit weight of soil. SSA is a fundamental soil property that can be used as an indicator of soil behavior (Utkaeva, 2007) to explain many of the physical and chemical phenomena of the soil: including fertility-determining components (such as the water holding capacity, the adsorption of plant nutrients, and the amount of organic matter) (Voronin, 1975). Measurement of specific surface area is time-consuming and relatively expensive; therefore, its estimation by routinely measured soil variables is preferred. In the present paper two pedotransfer functions for estimating of total SSA (including external and internal specific surface area) was presented, one a multivariate pedotransfer function based on the standard deviation of the diameter of soil particles and clay percent and second an exponential pedotransfer function based on slope of linear regression equation of logarithmic PSD Curve.

Due to the water shortage in developing countries, increasing the hydraulic performance and increasing the efficiency of water distribution in irrigation networks is necessary. One of the strategies for improving the efficiency of agricultural water productivity is increasing the accuracy of discharge measurement and controlling the water level. Gates are needed in order to control the amount of water released from dams and for regulating the water level in irrigation networks. There are different types of gates and the most common types of gates are sluice gates and radial gates. Gates are used widely in irrigation networks; therefore choosing small dimensions for the gates can reduce the channel costs. One of the ways for reducing the dimensions of the gate is to create a sill at the bottom of the canal and install the gate on the sill, so the design height of gate is reduced and it’s economically affordable. Estimation of the discharge coefficient of gate and consequently the amount of flow is one of the most important issues in hydraulic. The coefficient of discharge for free flow radial gates without the sill depends on the upstream water level and the gate opening (Bos, 1989). The objective of this paper is to investigate the effect of characteristics of sill such as the shape, height and location on the discharge coefficient for free flow radial gates. To achieve this goal, first the Flow-3D model’s output results for simulation of flow passing through a radial gate are validated using the experimental data and then the effect of the sill on the flow passing through a gate is examined.

Recently, Traffic phenomena is one of the most serious problems in most cities. It has had negative consequences on air quality and the quality of people’s life. By development of advanced technologies as intelligent control systems negative consequences have been significantly decreased. So, the aim of this study is to optimize and reduce vehicular emissions and fuel consumption of urban intersections in Boroujerd city by Fuzzy Logic (FL). For implementing this research, two softwares were used including Synchro 8 and Matlab software. The novelty of this research is to design optimized controller system for urban intersections. Additionally, this paper guides traffic engineers to control negative effects of traffic congestion over vehicular emissions and fuel consumption in a simple way. The results of comparisons between fuzzy logic and fixed time controllers for vehicular emissions, and fuel consumption are indicated.

Ultrasonic pulse waves velocities as a non-destructive test method has been utilized for assessing concrete properties. Most studies in this context were performed on specimens with no externally applied load and only were expressed the pulse wave velocity in terms of other concrete characteristics. Reinhardt and Grosse study showed that pulse wave velocity changes with different water to cement ratios for different cement types after 24 hours (Reinhardt & Grosse et al., 2004). The objective of this research was to study the pulse wave velocity of structural concrete under real conditions subjected to different loading and different intervals of compressive stresses and strains.  This can help to have a better understanding of concrete behavior and lead to an independent model from load- displacement parameter for health monitoring of concrete structures. To this aim, concrete cube specimens were prepared for cement content of 400 kg/m3, water to cement ratio from 0.3 to 0.5 with varying increment of 0.02 and equal ratio of fine to coarse aggregate.

The contamination of soil by crude oil and petroleum based products has become a serious problem that represents a global concern for the potential consequences on ecosystem and human health. There are many methods for the removal of these pollutants from soils. They involve both physico-chemical and biological approaches. The oxidants widely used for soil remediation include Fenton’s reagent, ozone, and permanganate. Ozone is a very strong oxidizer (Eh = -2.07 V). Decomposition of ozone produces free radicals, such as the hydroxyl radical, which is non-selective and a more powerful oxidant than ozone itself. Moreover, ozone that has not reacted reverts back to atmospheric oxygen and therefore no toxic residues of the oxidant remain in the soil.

Fresh caustic scrubbing is commonly applied in petrochemical and refinery plants for sweetening process. The wastewater produced is known spent caustic wastewater, Spent caustic contains noxious components such as sulfur compounds, phenol, mercaptans, and high COD. A various treatment methods exist. Treatment of spent caustic can be carried out by either biological or oxidation, each of which can be divided into subcategories. The chemical oxidation is divided into three way wet air oxidation (WAO), advanced oxidation (AOP) and catalytic oxidation (CAO) (Karimi et al, 2016; alniazy, 2008). In this work, the treatment methodology of spent caustic wastewater was investigated by applying the analytic hierarchy process (AHP) and finally is simulated optimal method via Aspen Hysys software.

The durability-based design of reinforced concrete structures especially in hot marine environment of Bandar-Abbas became extensively important during the last few years. It has been known that the durability of concrete mainly depends on how easily seawater containing chloride ions can ingress into an unsaturated concrete (Sabir et al., 1998; Hubert et al., 2003; Prabakar et al., 2010; Yoo et al., 2011). Chloride-induced corrosion of embedded reinforcement is more severe in tidal condition because of more ingress of chloride due to moisture convection phenomena. (Broomfield, 1997; Olajumok et al., 2009; Akindahunsi et al., 2010). In is necessary to approximate the moisture distribution in concrete due to wetting and drying cycles for determination of the moisture convection zone. The moisture transfer coefficient (MTC) is one of the most important parameters for prediction of moisture distribution. The moisture distribution is often influenced by environmental conditions such as temperature. The changes of the depth of convection zone can be assessed if MTC is available in various temperatures. In this research, six concrete mixtures were prepared in which four plain concrete mixtures were proportioned with water to cementitious materials (w/cm) ratios of 0.40, 0.45, 0.50, and 0.55. In addition to the plain concretes, one silica fume and one natural zeolite blended concrete mixtures with cement replacement levels of 7.5, and 10% and a w/cm ratio of 0.45 were considered. The moisture loss or water absorption of specimens exposed to wetting and drying were measured using the gravimetric method at temperatures of 23, 43, and 63 ºC. A finite element analysis was performed afterward to fit the experimental data to the governing equations of moisture transfer to determine the MTC. The moisture distribution of concrete exposed to wetting and drying and then the depth of convection zone (DCZ) are determined using approximated MTC and finite element-based model. The amount of water entered (AWE) to concrete surface subjected to tidal condition is also calculated.

Soil friction angle is one of the basic parameters in determining the shear strength of coarse-grained soils, which is often determined in the laboratory by spending a time and cost, and the use of field experiments has solved this problem. In this regard, Standard Penetration Test (SPT) is one of the most practical field tests that is commonly used in granular soils. In recent years many researches are proposed that present the correlation SPT and shear wave velocity, undrain shear strength and friction angle. Many correlations between SPT and soil friction angle are proposed but most equation with SPT numbers greater than 35 predict the right answers. The correlation between SPT results and soil bearing capacity has been studied and reported by various researchers.  In additional, some correlation between SPT and Soil friction angle have been proposed that each of those evaluated the material of specific area. In this paper new practical equation is proposed that presents an acceptable result in all SPT numbers. With use of this equation, the results can be predicted more accurately.