Journal of Civil Aspects and Structural Engineering
Volume:1 Issue: 1, Winter 2024

This research aimed to predict the bearing capacity of hammer piles using genetic and Lorenberg algorithms and Machine Learning (ML) methods. The studied samples as input parameters in this research include the parameters of soil internal friction angle, soil elastic modulus, pile diameter (D), and pile length (L) as input to the considered models, and the target in this research is the bearing capacity of the pile. 15% of the input data were considered training data, 15% validation data, and neural network training was done. At first, using the trial and error method, the number of hidden layers was determined as 6, and the target network was trained using the genetic algorithm. The results of training the target network using the genetic algorithm showed that the regression coefficient obtained from the model prediction for the learning and validation data was 99. 0 has been obtained. The results of neural network training using Lorenberg's algorithm showed that the correlation coefficient between training and validation data is 0.96548 and 0.993889, respectively. By comparing the results of the neural network with the laboratory data, it has been observed that the genetic algorithm can make the desired prediction better.

Waste production has been with humans since the first days of the formation of human society and concentration in a specific place, and also since the distant past, waste production and waste disposal methods have been problematic for humans, and this issue has caused that various methods for waste disposal are used. Since construction activities are among the most important economic parts of any society, this industry produces a large amount of waste every year, which is increasing with the increasing number of worn-out fabrics and construction in different levels of the country. In this study, by studying and researching the methods of disposal and management of construction and demolition waste, traditional and old methods should be left aside and a step should be taken in the direction of better management of time, economy and environment. Waste management is not discussed much in our country, although it is an important and vital topic in developed countries, because compliance with standards and using the right methods for its management in various fields will help people and the environment. The environment that should be addressed more than ever today and efforts should be made to preserve it because there is no substitute for it in case of any damage.

Recent advances in polymer science, chemical synthesis, and engineering have increased the importance of polyolefins in structural applications. Polyolefin fibers have good tensile properties, wear resistance, and excellent chemical resistance, slowing the development of crack length and width. Studying the role of polyolefin fibers in two combined forms on the resistance properties of concrete is one of the main goals of this research. The samples were examined at 7 and 28 days for compression, tension, and elastic modulus tests. Two designs without fibers and four with needle and mesh fibers were combined in two water-cement ratios to investigate the effect of fiber integration on concrete properties. In these designs, the amount of super-plasticizer was permanently fixed, and the fibers were used in two volume percentages of 0.2 and 0.3 with equal lengths. Fibers reduced concrete slump loss and increased compressive strength, tensile strength, and elastic modulus, respectively 52.60, 44.29 and 26.74% compared to the original design. In total, fibers with a volume of 0.3% have resulted in higher resistance in the investigated properties of the research.

Today, concrete is widely used due to the use of materials with a lower price and good durability, and based on the development of common concrete technology, the construction of high-strength concrete has become popular in the design of executive structures in advanced countries of the world. According to some regulations, the minimum resistance for high-strength concrete is considered to be 55 MPa, and a resistance of this level is more attainable in laboratory conditions. Among its advantages, we can mention the increase in strength and hardness, which can reduce horizontal displacements, as well as the length of restraint and patch of rebars. Also, in order to reduce environmental pollution and increase the durability and reliability of the structure, the use of Micro Silica (MS) and Rice Husk Ash (RHA) instead of a part of all cement consumption is considered. This thesis deals with the properties of concrete containing MS and RHA. In total, two mixing plans were made with two water-to-cement ratios of 0.37 and ratios at the age of 7 and 28 days. The durability performance of high-strength concrete containing RHA and MS was measured using compressive strength, tensile strength, and elastic modulus tests. The results of the tests show that the compressive strength of concrete containing MS is higher than that of concrete containing RHA, and the tensile strength of concrete containing RHA is higher than the compressive strength of concrete containing microsilica.

When a critical load such as (floods, explosions, earthquakes, or fire) enters the structure, the severity of the critical load depends on the strength of the load-bearing elements of the structure, whether the structure is completely destroyed or remains intact. Or some members are out of basic mode. Progressive failure is a nonlinear phenomenon that starts from the damage of a part of the structure and ends with the entire structure and its total destruction. Progressive failure is usually in the structure due to the loss of one of the main members, a column. A column in the structure at the node where the column is removed causes a location change with a seismic nature. This change of location has occurred, and the dynamic analysis's explanation of the force caused by removing the column on other elements is desired. It is checked that the side columns of the removed column can bear the explained load, or after explaining the load on the columns, they are destroyed due to buckling and breakage. This study uses the Alternative Path (AP) method, independent of the failure factor proposed by GSA and DoD. Nonlinear dynamic analysis is also used. Two types of column removal scenarios have been used. Since the AP method is independent of the failure factor, two concentrated loads with a very large size and opposite direction (more than the capacity of the column) are instantly entered into the ground floor column (shearing the column) and cause column failure. The research was conducted in three models on the 5, 10, and 15 floors, and the results are discussed.

This research was conducted with the aim of investigating the structural model of project productivity management based on knowledge and risk management in municipal construction projects. The present research is in the category of quantitative research in terms of practical purpose and descriptive survey method. The statistical population of the research consists of all employees of Sari City municipality. The sample size in this research, according to Klein's theory in 2014, 291 samples were selected purposefully. The data collection tools in this research included productivity management questionnaires, the Blish risk management questionnaire and the Nonaka and Takachi risk management questionnaire that use and create in 2009. The method of conducting the present research is that after preparing the mentioned questionnaires, its link has been provided online to statistical samples and the respondents answered each of the questions raised in the questionnaire. Data analysis was done using SPSS26 and AMOS software. The findings of the research showed that the effect coefficient of knowledge management and risk management on the productivity of construction projects is 0.44 and 0.54, respectively, which is statistically significant.

Reinforced concrete with steel fibers has become prevalent in structural engineering in recent decades due to its good mechanical performance. The primary purpose of this study is to increase concrete resistance properties using steel fibers and polypropylene. The reduction of cement consumption in concrete by using rice husk ash pozzolan was 10%, which replaced part of the cement. The effect of hooked steel fibers with two different diameters and corrugated steel fibers on compressive and tensile strength and modulus of elasticity with the same mixing design on standard cubic and cylindrical samples at 7 and 28 days was studied. The highest compressive strength of concrete contains hooked fibers with a diameter of 0.8 mm, and this increase reached 102% at the age of 28 days of concrete. The maximum tensile strength was also at 28 days of concrete with 0.8 mm diameter hooked fibers, which increased by 22% compared to concrete without fibers. The highest increase in the modulus of elasticity is also seen in sinusoidal fibers, which have a value of 29.6 GPa and a 19% increase compared to concrete. As the compressive strength increased, the modulus of elasticity also increased.

Due to the use of concrete structures in climatic conditions, the problem of damage to these types of structures and, as a result, their repair and maintenance is one of the main issues of experts. Nanop articles have shown unique physical and chemical properties compared to other materials. Self-Compacting Concrete (SCC) is a new technology in world construction. It fills the form without external and internal vibrators and only uses the force of weight to maintain its uniformity simultaneously. Also, in the advanced industry, nanotechnology has created tremendous changes in the concrete industry, and with the production of nanomaterials, significant changes are seen in increasing the strength and durability of concrete. This research has tried to investigate the effect of adding nanomaterials on the properties of concrete while achieving specific mixing plans for making SCC. These tests were performed on the obtained mixing designs, and the samples were examined at ages 7, 28, 90, and 180. The results showed that adding these materials increased compressive and tensile strength. Also, it was observed in other studies that with the increase of nanomaterials, water absorption by concrete decreased a lot, and it was also observed in the study of electrical resistance that these nanomaterials played a significant role in increasing the electrical resistance of concrete. The increase in electrical resistance and, as a result, the decrease in conductivity prevents the corrosion and loss of round rods and other metals used in concrete.

This research aims to create new ways to create information about architecture, and then, according to the things presented above, it describes and examines the main and secondary indicators. The purpose of this study is to investigate the concept, advantages, limitations, and challenges of public-private collaboration of BIM and SCM. The main indicators in this research are management factors and project beneficiaries, technical and infrastructure factors, financial factors, and safety and quality factors. After identifying the small signs and symptoms, first, by placing the big signs, the ranking of the two comparisons related to the big signs is entered into the Selection Expert program. Then, their weight is determined based on the AHP algorithm. The findings of the research show that the criterion of managerial factors and project stakeholders with a weight of (0.449) is the most important in examining the use of Building Information Modeling (BIM) in facilitating construction management and sustainable development in Supply Chain Management (SCM) in the construction industry. and the criteria of technical and infrastructural factors, economic factors and security and quality factors are ranked second to fourth with weights of 0.288, 0.152, 0.138 and 0.126 respectively. On the other hand, among the five objectives investigated, the option of reducing cost and time wastage with a weight of 0.279 is the best effect of using BIM in facilitating construction management and sustainable development in SCM. The selected construction industry, as well as the goals of improving operational efficiency, quality, and productivity, are ranked second and third with a difference of 4.66% and 17.20%, respectively.

There is always a need to improve the structures for many reasons, including changing the use, changing the design regulations, increasing the life of the structure, and improper implementation of the structures. One of the most influential parameters in the selection of the improvement method is the lateral stiffness of the target structure, which is determined according to the lateral bearing system of the structure. There are many methods for improving structures, including the use of steel jackets to increase the load capacity of columns and the use of FRP fibers, etc. The transfer of ground movement to the structure can be controlled with the help of the base seismic isolator system at the base of the structure; the base seismic isolator isolates the upper structure from the ground shaking movements so that the destructive forces of the earthquake do not enter the building or to a significant extent be reduced. The Malaysian Rubber Materials Research Company in England has produced a type of elastomer with high damping. Using this elastomer, a rubber seismic isolator system with high damping has been used for the seismic isolator of buildings. In some systems, the Teflon layer is used to cause slippage between steel sheets. A central lead core is provided to control lateral displacement and return the system to its original state. Progressive failure is the failure of the entire structure, or a relatively large part of it, caused by events that damage a part of the structure and the inability of adjacent members to redistribute the overload through a path that can maintain the stability and continuity of the entire structure. Progressive failure may occur as a result of abnormal loading such as explosion, severe fire, vehicles hitting a part of the structure, etc. The lateral bearing system is part of a structure that is responsible for resisting lateral loads and directing them from a safe path to the foundation (lateral forces can include wind, earthquake, or other forces). Earthquake-resistant elements should be considered in such a way that the torsion caused by these effective and resistant forces in the floors is minimized. For this purpose, it is suitable for the distance between the center of mass and the center of stiffness in each floor and extension to be less than 5% of the dimension of the building in that extension.

This research was carried out with the aim of identifying the effective factors in the construction of Reinforced Concrete (RC) beams. The current research was applied from the point of view of the objective and descriptive survey from the point of view. The statistical population of the research included all experts in the construction industry, from which 10 experts were selected for weighting and choosing the best strategy. In this research, data analysis was done using the Swaraphazi method to determine the weight of criteria, and the Electra method was used to choose the best strategy for reinforcing RC beams. The findings of the research showed that the order of importance of the criteria in the selection of reinforcement strategies for RC beams is as follows: time (C1) with a weight of 0.33 ranks first, cost with a weight of 0.22 (C4), high volume of operations (C5) with a weight of 0.15 ranks third, compatibility with climate (C2) with a weight of 0.1 in the fourth rank is the information of the employer, consultants and contractors (C3) with a weight of 0.062 in the fifth rank, the effectiveness of quality (C10) with a weight of 0.043 in the sixth rank, separation of the reinforcing page (C6) with a weight of 0.028 in the rank seventh, expert people (C7) with a weight of 0.019 in the eighth place, access to material C12 with a weight of 0.012 in the ninth place, the possibility of creating the required coverage C11 with a weight of 0.008 in the tenth place, the complexity of calculations C9 in the eleventh place and C8 transport were ranked 12th. Also, the results of Electra analysis showed that the best strategy for strengthening concrete beams was to use Glass Fiber Reinforced Polymer (GFRP) composites and to use Sisal Fiber Reinforced Polymer (SFRP)composite.