Number 1 Volume 21

Open Access Article

1 - Modeling the Reduction of Construction waste Production using the Concept of Lean Construction, Dimetal Technique and Cause and Effect Relationships
ali poornamazian mohsen izadinia

Production of construction waste In this research, the factors affecting waste production have been identified from previous articles, preliminary questionnaires and interviews.aste is one of the most important factors affecting performance and cost increase in construc More

Production of construction waste In this research, the factors affecting waste production have been identified from previous articles, preliminary questionnaires and interviews.aste is one of the most important factors affecting performance and cost increase in construction projects. In the next step, the final questionnaire was prepared. Then, the relationship between the variables and the cause-and-effect relationships was carried out through the system thinking approach and Dimtel technique to confirm the cause-and-effect relationships according to the pairwise comparison questionnaire among ten identified experts. Also, lean construction was used as a solution to reduce waste production. Lean construction follows new rules and without using new technologies or updating equipment with minimum use of resources, minimum waste and maximum productivity in construction projects. The main purpose of this article is to use the concept of lean construction and the system dynamics method to identify the main causes of waste production in construction projects. The main focus of lean construction is to analyze waste production processes, improve activities to reduce waste production and increase performance in construction projects. First, the effective factors on reducing the production of construction waste were identified through previous researches, and then a survey (interview and questionnaire) was conducted with experts in the case study of the waste management organization in the metropolis of Isfahan. In the next step, 52 questionnaires were prepared and distributed in the case study of the research. After collecting the information, the data obtained from the questionnaire was analyzed using statistics after checking its validity and reliability. In the last stage, after confirming the effective factors in the production of construction waste and how they are related, in order to develop a conceptual framework, cause-and-effect diagrams were drawn. The statistical results showed that the first to third most important factors affecting the reduction of construction waste with lean construction approach, flow perspective, identification of waste from the point of view of transformation and identification of waste from the point of view of value were the most important according to the experts in the waste management organization. Also, cause-and-effect relationships were confirmed through Dimtel's method. As a result, considering the relationship of correlation as well as cause and effect relationship, the way of communication between variables has been rooted through cause and effect circles and systemic thinking Manuscript profile

Open Access Article

2 - Seismic Optimization of Steel Moment Resisting Frame Using Uniform Deformation Algorithm
Amir hassan Alizadeh Mehdi Rahimi Asl

The overall aim of conducting this research is to optimize the medium steel bending frame in the level of life safety risk according to FEMA 350. For this purpose, two 3- and 5- story steel structures have been considered. These structures were designed according to AIS More

The overall aim of conducting this research is to optimize the medium steel bending frame in the level of life safety risk according to FEMA 350. For this purpose, two 3- and 5- story steel structures have been considered. These structures were designed according to AISC regulations and then subjected to seismic optimization using uniform deformation algorithm. The method of uniform deformations, which is one of the fast methods in optimization based on performance criteria, has been used for optimization so that the dispersion of plastic rotations created in the structural components reaches the lowest value and convinces the permissible plastic rotations at the level of life safety risk based on FEMA regulations. Opensees open-source software based on nonlinear time history method was used for modeling. The aim of optimization is to achieve appropriate performance at the risk level and performance level simultaneously. Also, the improved structure has been subjected to earthquake records with different intensities and its performance has been examined. The results indicate that in the process of using this algorithm, convergence is well-established and the use of the objective function of plastic rotations is considered one of the most suitable methods in the optimization of steel structures. Changes in the distribution of materials from structural components have been made mainly from the upper stories towards the lower stories and from the side members to the inner members of the frame. Also, the optimization in the level of life safety performance reduces the weight of both structures and leads to a reduction in their weight between 9 and 20 percent. Manuscript profile

Open Access Article

3 - Multiple Simultaneous Damage Detection in large-span bridges
محمد وحیدی آرمین عطیمی نژاد مریم فیروزی محمد هریسچیان

This paper presents a powerful two-step method for damage detection of large-span bridges with variable sections. Bridges are one of the basic infrastructures in the field of urban and suburban transportation, and timely detection of damage during its operation is impor More

This paper presents a powerful two-step method for damage detection of large-span bridges with variable sections. Bridges are one of the basic infrastructures in the field of urban and suburban transportation, and timely detection of damage during its operation is important. Damage in this category of structures will cause service disruption during natural disasters. The presented method is based on the combination of spectral finite element and modal strain energy damage index, as well as the combination of genetic algorithm and support vector regression to detect and estimate the damage severity. One of the efficient methods in the field of wave propagation is the spectral finite element method, which is capable of modeling with high flexibility and detecting micro damage. Vibration-based methods are widely used to detect structural damage, while the modal strain energy damage index has a higher sensitivity in detecting damage among other vibration-based methods. The case study model is the Crowchild Bridge in Western Canada, which has special characteristics in terms of geometry and the characteristics of structural elements. In this research, the modal strain energy damage index has been modified due to the change of cross-section along the girders. Also, support vector regression has been used as a robust technique in estimation damage severity. In order to increase the accuracy and improve the damage severity estimation method, the genetic algorithm is used to optimize the effective parameters of the support vector regression. The combined method of genetic algorithm and support vector regression has been able to estimate the severity of damages in a favorable way. Manuscript profile

Open Access Article

4 - Risk Analysis, Risk Assessment and Creation of Damage Probability Model for Yasouj City in OpenQuake Software
Ali Sadeghi عبدالرضا سروقدمقدم فرشید فتحی

The populous country of Iran is geographically located in a region with very high seismicity, and there is a need for detailed analyzes of seismic risk and risk in it, especially for strategic demographic and industrial points in order to provide vital information for d More

The populous country of Iran is geographically located in a region with very high seismicity, and there is a need for detailed analyzes of seismic risk and risk in it, especially for strategic demographic and industrial points in order to provide vital information for decision making. It is inevitable for recipients to develop effective risk reduction measures. This article, by using accurate and up-to-date methods, recent information of the population and housing census, socio-economic data, for the first time, analyzes the seismic risk by considering various uncertainties for buildings with was done various structural systems in the city of Yasouj. Descriptive and quantitative information of buildings and active faults in the field of this city is implemented in GIS software and using the capabilities of OpenQuake software, risk probabilistic analysis and risk curves and design spectrum for the building of the field are performed. Research has been produced. Based on this, probabilistic risk analysis has been done by considering various uncertainties in OpenQuake software and seismic risk curves have been produced for four different levels of vulnerability. The quantitative analysis of building vulnerability in Yasouj City reveals that unreinforced masonry buildings exhibit the highest damage percentages across all severity levels, with 48.4%, 43.1%, 39.4%, and 33.5% for slight, moderate, extensive, and collapse damage, respectively. Low-quality steel buildings suffer the most damage after unreinforced masonry structures, emphasizing the urgent need for retrofitting. In contrast, moderate-quality steel and reinforced concrete buildings demonstrate favorable seismic damage assessments. The qualitative findings stress the importance of implementing a robust monitoring/control system for construction quality, anticipating a significant improvement in structural reliability during the exploitation period with average to high execution quality. The results show that in order to prevent high economic, social and human damages, it is very important to review the design of new resistant structures and retrofit existing buildings in the research area. Manuscript profile

Open Access Article

5 - Numerical Study on the Effect of Piles Embedded Length based on Dynamic Parameters of Soldier Piles
Farnaz Farhadi فریبا بهروزسرند

One of the excavation stability methods is the use of a reinforced concrete piles system. In grounds with loose soil, the penetration amount of the pile tip in condensed soil, is one of the determinant parameters of pile stability. In this research, the influence of pi More

One of the excavation stability methods is the use of a reinforced concrete piles system. In grounds with loose soil, the penetration amount of the pile tip in condensed soil, is one of the determinant parameters of pile stability. In this research, the influence of pile penetration length in dense soil (dense sand) by changing soil layering and also by applying acceleration mapping of two earthquakes, Ahar-Varzghan (2013) and Bam (2003), has been investigated using Plexis software. The results show that with the increase in the loose soil depth in the mentioned earthquakes, in addition to the increase in the bending moment, the horizontal deformations in the static and dynamic states compared to the base model are 18 and 6 times, respectively, and the vertical deformations in the static and dynamic states compared to the base model are 48 and 6 times, respectively, and the total deformations in the static and dynamic models compared to the base model increase by 18 and 7 times, respectively. Rupture in the pit occurs when the depth of loose soil reaches 9 meters. Manuscript profile

Open Access Article

6 - Evaluation of Wavelet Energy for the Vibration of a Single Pile Embedded in Sand under the Effect of Near-Field and Far-Field Earthquakes
Navid Hasanpouri Notash روزبه دبیری Masoud Hajialilue Bonab Larissa Khodadadi فریبا بهروز سرند

Evaluating pile performance against seismic loading is one of the most important issues in geotechnical engineering. Various approaches are used in the evaluation of this performance, which can be referred to as continuous and discrete approaches. In the continuous appr More

Evaluating pile performance against seismic loading is one of the most important issues in geotechnical engineering. Various approaches are used in the evaluation of this performance, which can be referred to as continuous and discrete approaches. In the continuous approach, two-dimensional and three-dimensional analyzes can be used. One of the very important disadvantages that can be pointed out in the three-dimensional analyzes of piles is the increase in computational costs. Therefore, improving the accuracy of two-dimensional analyzes in order to reduce computational costs is inevitable. The present study has used Abaqus finite element software to evaluate the response of a single pile embedded in single— and double-layer sand under two earthquake records (far-field and near-field). The subsequent stage involved employing the wavelet transformation technique to analyze the signal derived from the pile cross-section. The present study utilized the acceleration time histories of the pile head as the input signal for wavelet transformation. The result showed that the wavelet energy for the pile head signal was higher in the near-field record than in the far-field record. The analysis indicated an 11% and 41% increase in wavelet energy for single-layer and double-layer profiles, respectively. This increase in wavelet energy is due to the significant increase in horizontal displacement of the pile under near-field records compared to far-field records. Therefore, by implementing signal processing analysis employing continuous wavelet transformation on the horizontal acceleration of the pile section, relevant information regarding the type of earthquake records that occurred at the site can be extracted. Manuscript profile

Open Access Article

7 - Improving Hysteresis Performance Steel Frames with Diagonal Bracing
مرتضی جمشیدی

A concentrically braced frame (CBF) is a conventional frame to provide lateral strength and stiffness. CBFs have less ductility and energy dissipation capacity. Studies on the lateral behavior of CBF show that the ductility and seismic behavior of these frames are inten More

A concentrically braced frame (CBF) is a conventional frame to provide lateral strength and stiffness. CBFs have less ductility and energy dissipation capacity. Studies on the lateral behavior of CBF show that the ductility and seismic behavior of these frames are intensively affected by the compression element behavior; and stiffness and strength reduction after the compression element buckling decreases the CBF performance under cyclic loading considerably. In this paper, a steel yielding device constructed with waste materials is proposed to improve the hysteresis performance of the CBFs. The hysteresis performance of the proposed device is studied through experimental and numerical studies. Experimental and numerical studies show the stable hysteresis performance of the proposed device and its appropriate energy dissipation capacity. In the case of the studied device, no strength and stiffness reduction is observed up to 18 mm axial displacement. 2. On the other hand, achieving equivalent viscous damping ratio for the damper constructed with IPE80 without the use of sophisticated tools is noticeable. Manuscript profile

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