Journal of Civil Engineering
Volume:7 Issue: 2, Spring 2023

Nowadays, partial cement replacement with natural pozzolans like zeolite and use of reinforcing agents such as fibers have been extensively used in the field of soil stabilization. In the current paper, the effects of incorporation of polypropylene fibers and zeolite in a typical cemented sand have been examined. A set of unconfined compression strength (UCS) tests considering three distinct porosities (related to Dr = 35, 50, 70 and 85% sand), four cement contents (2, 4, 6, 8 and 10%), six different percentages of cement replacement with zeolite (0, 10, 30, 50, 70 and 90%) and the fiber content (0.5% by weight of cement in the mixture) has been performed. Then, the amounts of improved unconfined compressive strength (UCS) of the specimens as the result of zeolite and cement chemical properties have been estimated. Results indicate that the optimum amount of cement replacement by zeolite is 30%. Studies on zeolite-cement-sand mixtures reinforced by fibers have also shown that UCS improves in case cement content (C) and porosity (η) go up. Parameter (SiO2+Al2O3) which are active particles (AP) participate in the chemical reaction introduced and UCS-AP diagrams have been drawn. Afterwards, UCS has been plotted against η/AP which is considered as a controlling parameter of UCS. This experimental research and the parameter η^(-1.79) 〖AP〗^1.43 will introduce an acceptable description of mechanical properties. Finally, the effect of reinforcing agent in the mixture has been thoroughly studied through SEM analysis.

The success of a logistic center fundamentally depends on the cost-minimizing and on-time delivery of services to its customers. Location selection problem in an international scope is the main factor in providing an appropriate service. Thus, we aimed to find the best location to establish the logistic center. Here, two robust multi-criteria decision-making (MCDM) methods of gray relational analysis and analytic hierarchy process (AHP) were applied for the selection of a logistic center location in the Iranian northern territory. The application of these methods can be reduced by decision-makers subjectively, which ultimately results in consistency in the weight value of the criteria. The criteria were evaluated based on various industrial project establishment requirements, including environmental, accessibility, social and economic, and location factors. These distinguish the current research from the other studies that focus on the demand and supply of a logistic to establish such a center. The results suggest that the AHP and gray relational are feasible methods for logistic and engineering location selection that effectively investigate this project's most important factors and identify a suitable alternative. The findings of our data suggest that in terms of environmental and accessibility factors, Astara port with grades of gray 0.8018 and 0.8184, was the best alternative compared to its competitors. However, in socioeconomic and location factors, the other ports were the best option. In conclusion, we recommend a short and long-term analysis of the financial and economic consequences of the project where all the alternatives’ related costs are investigated in detail.

Aggressive driving is perceived by many users as one of the most important problems in driving. Aggressive driving is a crucial problem in Iran and also in many other countries. The purpose of this study is to analyze the driving aggression conceptual model and the assess effect of the theory of planned behavior subsets on the aggressive driving behavior questionnaire and determine the index for aggressive driving behavior. Drivers’ behavior is assessed with a questionnaire that included 54 questions and was randomly distributed among 400 drivers. Confirmatory factor analysis, Structural Equations Model, and regression are used to analyze the data. Demographic variables, theory of planned behavior, and Shinar’s model variable are considered in this study. Fitness indicators such as Goodness of Fit Index (GFI) and Adjusted Goodness of Fit Index (AGFI), respectively equal to 0.98 and 0.93, pointed out that the model is reliable. The Root Mean Square Error of Approximation (RMSEA) also indicates that the model is suitable and its value is RMSEA ≤ 0.08. The comparative fit index value is greater than or equal to 9.0 and in line with other indices, confirming the model is good. In this way, the model presented in the study has proper and consistent indicators (X^2=81.9 p<0.000, AGFI=0.93, GFI= 0.98, RMSEA =0.064), theories and other factors are able to explain aggressive behavior. The personality traits do not play a role in explaining the drivers’ aggressive behavior. The subjective norm, and perceived behavior control are related directly to the drivers’ aggressive behavior. Drivers’ demographic characteristics are analyzed with regression and they do not play any role in aggressive behavior. Also, attitude has the greatest impact from which it can be stated that the theory of planned behavior has an indirect effect on aggressive behavior. The present study identifies that the theory of planned behavior components is directly associated with aggressive driving behavior>

The piano key side weir is introduced as a new hydraulic structure to improve the outflow performance where the opening length of distribution channels is restricted. This study used 370 high-resolution tests on three linear and 24 triangular piano key side weirs. The study experimentally investigates the effects of different upstream angles on the discharge coefficient of the triangular piano key side weirs with various geometries. In these tests, continuous improvement has been achieved by reducing the ratio of upstream angles for triangular piano key side weirs with the same crest length. The estimation of discharge coefficients using De Marchi’s equation shows an average increase of 7.2% to 17% for the triangular piano key side weirs, considering the variation of upstream angles. The data analysis shows that the deflection angles of triangular piano key side weirs are also vital for outflow efficiency. A new reliable equation is proposed to estimate the discharge coefficient of piano key side weirs based on some dimensionless parameters (different ratios of upstream angles (δ1/δ2), dimensionless weir length (L/W), dimensionless weir height (h1/P), dimensionless overhang length (h1/ Bi), and the downstream Froude number (F2). Also, the statistical indices were used to evaluate the precision of the nonlinear equation for triangular piano key side weirs. The R2 and MAE for 70% of the experimental data were 0.91 and 0.052, respectively.

It has been a long time since crude oil products and, their derivatives have contaminated soil. Crude oil contamination is an unavoidable consequence of rapid overpopulation and, the industrialization process. Crude oil contamination can change soil geotechnical behavior and, affect soil strength, foundation-bearing capacity, and slope stability. On the other hand, “mini-cone’ tests have rapidly become the most famous type of on-site testing. Because, the mini cone is a fast and, economical experiment that continuously provides information on the geological layout and, the proper assessment of soil properties. This paper compares the changes in the tip and, side resistance of the mini-cone. There are mixed soils of two types of fine-grained sand with 10%, 20%, 30%, 40%, and 50% kaolinite clay, which were tested with 4% and, 8% crude oil and, different moisture contents. These investigations have been done with the physical modeling method and, calculating the value of Ic, focusing on the mini-con data. Results showed that the tip and, the side resistances of the “mini-cone” were decreased in mixed soils with increasing crude oil content and, changes in moisture contents. Except for two sandy soils mixed with 10% and, 20% clay, which were mixed with 4% crude oil. There was an increase in tip and, side resistance due to the lack of the maximum density in the laboratory chamber compared to the standard Proctor test. Also, with these changes, Ic calculation found that the soil's behavior shifted towards finer soils.

One of the most important environmental challenges in today's era is climatic changes and fluctuations. The phenomenon of global warming has always affected different parts of the world. Therefore, it is necessary to investigate and predict the factors affecting it in various regions. In this study, the ARIMA time series method was used to investigate the future temperature changes in the climate of Aligoudarz Plain in western Iran. For this purpose, the monthly temperature information for the period of 1992-2023 was used from Aligoudarz station. The maximum data for 1992 is equal to 13.27 and the minimum data for 2021 is equal to 6.78. To assess the specification of time series ACF and PACF functions were used. The results showed that the time series is not Stationary. Therefore, the differentiation method was used for Stationary. The time series after one-time differentiation was Stationary, so the factor of d to 1. Results of the time series investigation showed that after evaluating different ARIMA models for the prediction of temperature, the model with the value of autocorrelation component=0, moving average=1, and differentiation=1 had the best result, so the forecasting was done with ARIMA(0,1,1) model. The forecast results showed that in the next five years (2024-2028) the temperature will decrease. In general, the results of this study showed the acceptable effectiveness of the time series model in temperature forecasting.