نشریه مهندسی عمران
سال پنجاه و ششم شماره 1 (فروردین 1403)

Estimating the water inflows to water resources systems is one of the essential measures for awareness of planning and allocating optimal water resources in different sectors of consumption. In this study, a combination of Meta Heuristic algorithms including the Water Cycle Algorithms (WCA), Grey Wolf Optimizer (GWO), Whale Optimization Algorithm (WOA), Neural Network Algorithm (NNA) and Grasshopper Optimization Algorithm (GOA) for Neural-Fuzzy System training and update parameters was used. Finally, the best models were developed to predict the daily inflow of Sefidrood reservoir dam. This method does not suffer from the problems of training gradient-based algorithms. Four features including dam lake area, reservoir volume and reservoir level of the dam in the 7 lags and inlet flow in the 1 lag were selected according to the AutocVarious statistical indicators were used to evaluate the performance of utilized models. In the test stage, ANFIS-WCA model presents the lowest values of SI, MAE and NRMSE equal to 0.0736, 0.05048 and 0.0736, respectively, and the maximum value of R^2equals to 0.9840, which indicates its superiority over other models. Based on GPI index, ANFIS-WCA model was selected as the best model and then ANFIS-NNA, ANFIS-GOA and ANFIS-WOA models were ranked, while the worst accuracy was obtained through the ANFIS-GOA model. The high accuracy of the ANFIS-WCA model compared to other hybrid models indicates the performance of the WCA for escaping local optimization in combination with the ANFIS model which has enabled this algorithm as a powerful tool for estimating the inflow of Sefidrood dam.

One of the methods to improve soft soil is to use embankments along with geo-synthetic reinforcement on piles. This embankment system is called piled embankment. The objective of designing this system was to transfer higher load to piles through embankment and reinforcement. Due to the phenomenon of soil arching in the embankment, part of the surgerch load (A) was directly transferred to the piles, reducing the remaining surgerch load (B) applied to the reinforcement between the piles. One of the objectives of piled embankment design regulations is that the reinforcement with less settlement can transfer higher load to the piles. In this article, 2D tests were first performed using rigid steel rods as embankments with 2D behavior. Then, analytical calculations were performed for the deflection of the reinforcement after the tests. The test device was designed and made in such a way that can measure the values of A and B separately. Studies on the variables of the embankment height and the number of reinforcing strands showed that by increasing the height of the embankment by 4 times due to the formation of a more stable arch and the distributed load accumulation near the piles, the reinforcement can transfer higher load up to 3.7 times to the piles with a fixed settlement. While by tripling the number of reinforcing strands, for a fixed settlement of the reinforcement, it can increase the maximum load transferred to the piles by 1.78 times.

The present research was conducted with the aim of investigating the effect of the type of filler on the mechanical properties of the stone mastic asphalt (SMA). For this purpose, five types of fillers, including silica filler (SF) as the base filler in the control sample, Portland cement (OPC) and limestone powder (LSP) as common fillers, and recycled glass powder (RGP) and calcium carbide waste (CCR) as recycled fillers, were used in their pure form or combined with each other. In order to investigate the resistance of the samples against rutting, the Marshall test was used to obtain the Marshall strength (MS) and especially the Marshall coefficient (MQ). Also, resistance to cracking and moisture sensitivity were also evaluated by performing the Indirect Tensile Strength (ITS) test in dry and saturated conditions and obtaining the Tensile Strength Ratio (TSR). The results have shown that the samples containing recycled fillers had the best performance in improving the properties of SMA asphalt. such that the use of the combination of recycled fillers, in addition to improving the properties of SMA compared to samples containing silica fillers, The values of MS, MQ, ITS, and TSR have increased by 36, 19, 24, and 31%, respectively, compared to the best results obtained using common fillers. Therefore, the use of RGP and CCR compounds as fillers in SMA asphalt, in addition to helping to protect the environment, natural resources and economic savings, can also be technically very effective in improving the service life of asphalt mixtures.

This research effort aims at investigating theoretical foundations of developing a competence baseline for project managers in Iran using the Grounded Theory approach. Based on a series of interviews, the competencies affecting the success of project were identified. Throughout these interviews, 551 codes were identified and open, axial, and selective coding was practiced to analyze the coded data, ending up codifying the causal conditions, contextual factors, strategies, and consequences. Considering the causal conditions, impacts of micro environmental factors and special conditions of the country on the project management were crystal clear. These causal conditions were observed to lead to a highly fluctuating environment, non-standard projects, poorly predictable behaviors, and regulations with person- or case-specific interpretations. In such a context where behavioral competences are affected by environmental conditions, one may refer, as a fundamental approach and a major part of the paradigm change to the second-order project management, to the greater importance of behavioral and environmental competencies rather than technical issues. At the same time, one may refer to the paradigm change from technical competencies to agility-based competencies that have roots in the PM-2 as an approach that worth considering. Consequences of these strategies include the necessity of ruling out the conventional structures of linear programming and rather paying attention to key competencies of project managers such as holism, persistent troubleshooting, instantaneous management, creativity and problem-solving capability, high mental preparedness, flexibility, commitment, and result-orientation, which are outcomes of the paradigm change to the PM-2.

Evaluating new construction technologies based on quantitative analysis and before applying the technology in the construction industry can minimize the risk of using a technology. The experimental part includes the review of the information of 45 types of implemented technologies, their field impressions and pathology, and in the theoretical part, the author designs 330 quantitative evaluation questions and receives the opinions of prestigious universities of the country regarding the proposed questions and finally presents the mathematical model of the evaluation criteria. The mathematical model presented for the first time by the author is presented in this article under the title of triangle of evaluation criteria of new construction technologies. The length of the sides of this triangle is equal to the score obtained from each of the questions related to the quality, cost and speed of construction for each technology, which are the three main criteria for quantitative evaluation of a technology. The evaluation triangle shows that if the length of the quality side becomes zero in the evaluation of a technology, it is a deterrent and ban on the use of that technology. Presenting the normalized triangle model for evaluation criteria was aimed at achieving a competitive goal. The length of each of the sides of this triangle can be between zero and 0.5 (except zero and 0.5), provided that the sum of the sides does not exceed one. In this model, if the length of one of the sides approaches zero, the result will be a skinny triangle.

Road crashes and their consequences are one of the most important problems that affect people's lives. In order to reduce the fatalities and related cost of crashes, traffic safety researchers are continuously investigating approaches to reduce the occurrence and consequences of crashes. Crash type modeling is one of the most common tools for road safety goals in transportation facilities, and the purpose of crash type modeling is to establish a relationship between the frequency of crashes based on its type and other effective variables. One of the advantages of crash type models is that with the help of these models, it is possible to identify the places where there is a possibility of a certain type of crashes and to examine the effect of different variables on different types of crashes. In this research, using the data of freeway accidents in Iran, the type of crash was identified with a new approach called nested logit model. To this aim, crashes were initially divided into two categories of single-vehicle and multi-vehicle crashes, and then single-vehicle crashes were divided into three categories of collision with a fixed object, off-road crashes, and overturning crashes, and multi-vehicle accidents were divided into two categories of collision with a vehicle and multi-vehicle collision crashes. Then the effect of different variables of environment, road, driver, and causes of crashes with different types of crashes were investigated and the effect of significant variables on each type of crash was explored with marginal effect.