Civil Engineering Journal (CivileJournal.org) - Academia.edu (original) (raw)
Papers by Civil Engineering Journal (CivileJournal.org)
Exact estimation of vibration fundamental period of structures plays a vital role in their design... more Exact estimation of vibration fundamental period of structures plays a vital role in their designing procedure. The proposition of a relatively exact expression which considers the effects of a pile group on the fundamental period of the structures was of less interest to previous researchers. This study aims to propose an analytical model and expression so as to estimate the free vibration period of the structures located on a pile group. To reach the objectives of this study, several numerical analyses has been carried out using the method of equivalent spring which takes into account the effects of soil-pile-structure interaction on the fundamental period of the structures. In the next step of the study the effects of a pile group on the fundamental period of the structures have been analyzed analytically. In this analytical study two cases have been considered for the piles which are end-bearing and floating piles. In the case of floating piles a five degrees-of-freedom analytical model and its corresponding expression have been proposed considering the soil-pile-structure system. The numerical modelling has been performed using the direct method due to the neglect of the soil in analytical expression and the results have been compared with those of the proposed analytical expression. The soil mass participation coefficient (λ) has been obtained using the discrepancy between the results of the two different methods t o modify the analytical expression. In the case of end-bearing piles an analytical model with three degrees-of-freedom and its corresponding expressions has been proposed. Then the soil has been neglected and a new analytical expression has been proposed using the mass participation coefficients adopted from other researches to calculate the fundamental period of the structures. The comparison between the results of the proposed expression and those of case and numerical studies confirms that the proposed expressions benefit from a relative accuracy and can be used as an initial criterion in designing procedure.
Countries from all over the world including Iran, consider different maximum allowable speeds to ... more Countries from all over the world including Iran, consider different maximum allowable speeds to control and maintain traffic safety on their freeways, but these actions have not been successful even with the police surveillance. Even though speeding is not the only cause of accidents, past studies indicate that speed plays a vital role in such events. Since respecting the speed limits have not prevented driving violations and traffic accidents, there's doubt among decision-makers, about the applicability and safety of these legal speed limits in different weather and traffic conditions. They think perhaps there is a need for an optimized and safe speed after doing required studies. Even in the police instructions and notifications in unfavorable weather conditions, the word " safe speed " is used more than the " legal speed " and its limit is not mentioned and its determination is assigned to drivers according to their mental and physical conditions, type of vehicle, and the weather condition. This matter leads to uncertainty for drivers in selecting the right speed.This research is intended to achieve a safe and optimized speed for freeways in Iran, by considering a reasonable adjustment which is acceptable by the drivers so that a substantial decrease in driving violations and accidents could be observed. This work is done by using models developed for predicting violations and accidents on Iran's freeways. The results indicate that by reducing the allowable speed of freeways from 125km/h to 105 km/h, a 48% and 23% reduction of violations and traffic accidents could be achieved.
This study deals with the intrinsic vulnerability of groundwater reservoirs to pollution, by the ... more This study deals with the intrinsic vulnerability of groundwater reservoirs to pollution, by the use of two models DRASTIC and GODS, this study is done by taking samples from 17 water resources of Malayer plain Aquifer area of southern Hamedan Province, Iran. 30 physicochemical parameters and heavy metals have been studied and vulnerability of this aquifer to the nitrate concentration, was determined. The study showed that results from DRASTIC were better than GODS in Assessment and Estimating groundwater vulnerability to pollution, also DRASTIC model has been corrected, and compared the ability of these two models in vulnerability zoning has been evaluated. According to high correlation between DRASTIC index and nitrate concentration, ranking and weighting of nitrate pollutant is inserted in the DRASTIC equation, and zoning map of DRASTIC method has been calibrated by nitrate concentration. By this method, vulnerability zoning is determined between very low to very high, which shows the increase of DRASTIC index by nitrate concentration. DRASTIC parameters uncertainty has affected the zoning results in this method, but its calibration with nitrate concentration, gives more accurate vulnerability results.
Nowadays, the development of construction industry is one of the development indices of countries... more Nowadays, the development of construction industry is one of the development indices of countries. On the other hand, development of construction industry is more urgent than ever with increased population and consequently, increased desire for urbanization. Considering the inadequacy of traditional and conventional systems for mass housing production, the approach to use modern industrial methods of building along with new technology and observance of the latest technical standards is critical. Therefore, the present study aimed to investigate and compare construction method of reinforced concrete cast in-situ walls and slabs with the conventional method of constructing concrete structures using MSP software. Studies show that the integrated wall and ceiling molding technique has been used since the late 1970s in the construction of high-rise residential towers. Currently, integrated wall and ceiling molding system is used as one of the methods in the construction of buildings with load-bearing wall and concrete ceiling. This method brings about improvements in quality, earthquake resistance, reduced run-time, reduced cost, quick return on investment, saving on materials consumption, reduced labor, eco-friendliness, sustainability and longer durability, reduced resource consumption, integrated structure, fire resistance, high flexibility, and employee safety.
Texture coefficient is one of the most influential parameters in rock engineering specifications ... more Texture coefficient is one of the most influential parameters in rock engineering specifications in various projects including drilling, cutting, permeability of all-section drilling devices, etc. Meanwhile, investigating and forecasting the energy consumption of saw cutters are one of the most important factors in estimating the cutting costs. The present study aims to investigate the relationship between rock texture characteristics and the amount of energy consumption of the gang saw machine in the process of cutting carbonate rocks. To evaluate the effects of texture on the rocks' engineering specifications, 14 carbonate rock samples were studied. A microscopic thin section was made from each rock specimen. Then, five digital images were taken from each section under a microscope and the values of area, environment, the largest diameter and the smallest diameter of all grains in each image were determined. Using these specifications, the coefficient of texture of all rock samples was calculated and the relationship between the texture coefficient and the rate of energy consumption of the gang saw machine was investigated for the studied samples. The study results indicated that there was a significant relation between the texture coefficient and energy consumption rate in the three groups of carbonate rocks.
One of the main causes of bridge collapse may be flood flow scour near piers. Several experimenta... more One of the main causes of bridge collapse may be flood flow scour near piers. Several experimental and local field investigations were carried out to study scour depth. However, existing empirical equations do not commonly provide accurate scour prediction due to the complexity of the scour process. Physical and economic considerations often lead to bridge foundation constructs which included a pier column based on a pile cap supported by an array of piles. Piers with this configuration are referred to as complex piers. A few studies have been done on complex bridge pier scour depth estimation. Such efforts may be classified into theoretical and empirical equations. This paper investigates local scour around complex bridge piers by using harmony search algorithm under clear water conditions. Statistical indices such as the coefficient of determination (R2), root mean square error (RMSE), mean absolute error (MAE), mean absolute percentage error (MAPE), and bias were used to evaluate the performance of these methods. By designing laboratory tests, 82 experimental data points were measured by authors. Also 615 experimental data sets with the same measured experimental conditions were collected from published literature and used for optimization. The results show that the developed HS model can predict scour depth better than other equations according to statistical indices.
Effectively enhancing buildings' adaptability, extending their service lives, and reducing constr... more Effectively enhancing buildings' adaptability, extending their service lives, and reducing construction wastes has become a crucial issue in the construction industry. As the transformation of the socioeconomic structure and diversification of user demands has grown, occupants in residence may have various needs in different stages, rethinking a sustainable and flexible living space has received substantial focus. " Open building (OB) " is an innovative method to accommodate various changeable occupant spaces, decrease the waste caused by space adjustment and reduce maintenance costs. Although the concept of OB is beneficial for sustainable built environments, the promotion of OB in Taiwan is constrained. One of the obstacles is that the OB approach is partly in conflict with the current building regulations. Without legally developed policies, developers are reluctant to supply OB housing in the market; occupants are unwilling to take the risk of implementing OB approaches in renovation. This study applied a Kano two-dimensional quality model to classify and prioritize OB regulation suggestions proposed by experts in Taiwan. A series of forums and interviews were conducted to develop OB regulations. Barriers and challenges will be discussed for further OB development that can be applied to improve building longevity, adaptability, and sustainability.
The goal of this study was twofold; first analyze the patterns of water consumption in Lagos, Nig... more The goal of this study was twofold; first analyze the patterns of water consumption in Lagos, Nigeria and use them in a System Dynamics (SD) model to make projections about future demand. The second part used remote sensing to quantify the contribution of extensive land use/cover change to urban flooding. Land use/cover dynamics over the past decade was analyzed using satellite imagery provided by Landsat Thematic Mapping (TM). Unsupervised classification was performed with false color composite using the Iterative Self-Organizing Data Analysis (ISODATA) technique in a Geographic Information Systems (GIS). The study area was divided into four different land use types during image classification: bare land, built-up area, water bodies, and vegetation. For water demand, two different scenarios of population growth including 5.5% and 2.75 % annual increase were considered. The results showed that water demand dropped by 67% of its current value when losses in distribution were reduced by 20% and population annual growth rate kept at 2.75% over the study period. Bare land and water bodies lost 1.31% and 1.61% of their current area respectively while built-up area grew by 1.11%. These changes in land use/cover changes led to a 64% increase in average surface runoff, mostly attributable to increasing surface imperviousness and the absence of an adequate urban drainage system.
Considering the increasing population growth and the rapid growth of urbanization and pollution i... more Considering the increasing population growth and the rapid growth of urbanization and pollution in the environment, providing zoning maps and urban engineering geology seem to be important. The rapid construction growth of cities, as well as the confrontation with events such as earthquakes and failure to observe the geological and geotechnical issues, has caused many engineering problems. The use of geophysical methods not only cannot lonely provide us a complete and comprehensive information on the geotechnical conditions of the earth but also has many disturbances in urban areas, and its use in urban centers is almost impractical. Therefore, it seems that the best way of examining and interpreting the geotechnical characteristics of a site, especially in urban areas, is the use of suspicious data. Therefore, performing geotechnical studies and geotechnical zoning can be useful for retrofitting buildings and engineering structures and reducing their risks. Hence, zoning studies are conducted in this research in order to better recognize the technical soil status for safe construction due to rising the population of Tehran in recent decades and the concentration of population in certain areas of Tehran, especially in the eastern and western regions (districts 4 and 22). In this study, different geotechnical field tests such as standard penetration test (SPT), cone penetration test (CPT) were used to estimate parameters such as adhesion coefficient (C), internal friction angle (í µí¼), Young modulus (E). Other common experiments with conventional geophysical experiments, such as in good experiments, refractive and CSSW were applied to estimate geophysical parameters of bedrock depth and shear wave velocity for zoning these areas.
During the service life, the asphalt pavement layers subjected to various detrimental types of di... more During the service life, the asphalt pavement layers subjected to various detrimental types of distresses such as permanent deformation, fatigue, stripping and shoving which lead to the complete failure of the pavement. In Iraq roads the permanent deformation (rutting) is the importance distresses which cause impact on the highway performance and reducing the service life of the pavement. The research aims to utilize locally available materials and environment friendly as reinforcement layer. The program of this research include preparing asphalt mixes represent surface layer by using locally available materials and using the reinforcement layer which made of reed. The permanent deformation test has been done with three temperatures (40˚C, 50˚C and 60˚C) and four locations of the reed mats. The test results of the wheel-Track for the rutting measurement showed that the rut depth decrease in reinforcement layers as compared with unreinforcement layers for all temperature testing. The reed netting embedded bottom and middle of wearing layer has the best amount of improvement (75%, 84% and 85%).
This study aimed to evaluate the possibility of reducing the thickness of asphalt layer as a nove... more This study aimed to evaluate the possibility of reducing the thickness of asphalt layer as a novel solution for the high density of asphalt layer incorporated with steel slag aggregate, which increase the cost of transportation. Mechanistic-Empirical Pavement Design (MEPDG) approach was employed to evaluate the benefits of introducing polyvinyl alcohol fiber in terms of reducing the thickness of asphalt layer as well as the extension service life of asphalt layer. On the other hand, the correlation between creep strain slope (CSS) and secant creep stiffness modulus (SCSM) were assessed to provide a better evaluation and understanding concerning of the outputs of the dynamic creep test. The findings of this study showed that introducing polyvinyl alcohol fiber into the mixtures at the optimum content (0.5 kg/ton) have reduced the thickness of asphalt layer by approximately 10%. Additionally, polyvinyl alcohol fiber has increased the performance of the asphalt mixtures concerning of resilient modulus and dynamic creep. Furthermore, the correlation between CSS and SCSM was strong, which indicates that evaluation of permanent deformation using CSS and SCSM parameters provides better actual assessment than accumulation strain.
Crack is one of the most common defects observed in reinforced concrete (RC) structures. An initi... more Crack is one of the most common defects observed in reinforced concrete (RC) structures. An initial crack will lead to severe changes in the stress state when the structure subjected to blast loadings. Target on acquiring the dynamic data, a finite element method is applied to simulate the response of cracked RC slab subjected to blast loading. The theoretical results of damage distribution and mid-span deflection of normal specimens are first compared with experimental test, which indicates that the dynamic behaviour of RC slab under blast loading can be well predicted by the finite element model. Then blast responses of cracked RC slabs with varied crack parameters (e.g. orientation, width and depth) are systematically studied. Results show that damage of the cracked slab initiates from the initial crack tip of the bottom surface, and then it propagates quickly with cracks found in the support areas on the top surface. In addition, the existence of initial cracks in the RC slab make it subject to more serious damages than the normal RC slab under the same explosive loads, as well as a short reacted failure time. Moreover, variations of crack parameters have slight influences on the distributions of cracked RC slab.
This paper presents a technique for irregular plate and regular dam damage detection based on com... more This paper presents a technique for irregular plate and regular dam damage detection based on combination of wavelet with adoptive neuro fuzzy inference system (ANFIS). Many damage detection methods need response of structures (such as the displacements, stresses or mode shapes) before and after damage, but this method only requires response of structures after damage, otherwise many damage detection methods study regular plate but this method also studies irregular plate. First, the structure (irregular plate or regular dam) is modelled by using ANSYS software, the model is analysed and structure's responses with damage are obtained by finite element approach. Second, the responses at the finite element points with regular distances are obtained by using ANFIS. The damage zone is represented as the elements with reduced elasticity modules. Then these responses of structures are analysed with 2D wavelet transform. It is shown that matrix detail coefficients of 2D wavelet transform can specified the damage zone of plates and regular dams by perturbation in the damaged area.
Excavator is heavy equipment that usually used in construction and mining works. Bucket teeth whi... more Excavator is heavy equipment that usually used in construction and mining works. Bucket teeth which are located in the tip of bucket excavator are used for digging works. They are easily damaged by direct contact with the media. One of the material used in bucket teeth excavator is mild carbon steel that has carbon content between 0.33%-0.5%. However, the hardness value of this material is not yet meets the standard of bucket teeth excavator so the optimum hardness value based on its heat treatment should be known. Besides that, its tensile, impact strength, and micro structure in optimum condition will also know. Optimization method was done through Taguchi experimental design with L9 orthogonal and ANOVA (Analysis of Variance). Factors or parameters in this research were heating temperature, holding time, quenching media, and tempering temperature. In this experiment, nine specimens of mild carbon steel were tested by different heating temperatures (850 o C, 875 o C, 900 o C), different holding times (60, 90, and 120 minutes), different quenching medias (oil, water, and salt water), and different tempering temperatures (250 o C, 450 o C, 650 o C). Calculation of Taguchi method and confirmation experiment showed that the optimum parameters of hardness are 875 o C heating temperature, 60 minutes holding time, water quenching media, and 250oC tempering temperature. Meanwhile, ANOVA test showed a result that the four factors had an effect on the bucket teeth excavator hardness.
Lightweight foamed concrete is a type of concrete characterized by light in self-weight, self-com... more Lightweight foamed concrete is a type of concrete characterized by light in self-weight, self-compaction, self-leveling, thermal isolation, and a high ratio of weight to strength. The advantages of GFRP bars include lightweight, high longitudinal tensile strength, non-conductivity, and resistance to corrosion. This study investigated the behavior of LWFC beams reinforced with GFRP bars under flexural loading. A total of four reinforced concrete beams were cast, where it consisted of two LWFC beams and two normal weight concrete beam which acted as control specimen. One of the lightweight foamed concrete beams and the normal concrete beams is reinforced with two GFRP bars and the other reinforced with two steel bars. All beams were designed with singly reinforced of two bars of diameter 12 mm. The LWFC beams were with cement to sand ratio (1:1) and average dried density of 1800± kg/m 3. The main variables considered in this study was type of concrete and type of reinforcement. The flexural parameters investigated are ultimate load, crack width, ductility, deflection and stiffness. The lightweight foamed concrete beam reinforced with GFRP bars showed deflection and crack width greater than in beam reinforced with steel bars due to the low modulus of elasticity of GFRP bars.
This paper presents the experimental study of Soil-Cement Pile (SCpile) by wet mixing method in s... more This paper presents the experimental study of Soil-Cement Pile (SCpile) by wet mixing method in sandy soils, with the typical project at An Trung Complex apartment, Da Nang city, Vietnam. With the characteristic of soil layers is sandy soil, the strength of laboratory stabilized soils with the amount of cement from 150300 kg/m 3 was determined. Simultaneously, the authors also performed the experiments of 20 test piles collected from the site which has cement content about 280 kg/m 3 and the unconfined compressive strength qu= (4.56.0) MPa. After that, a full-scale model static axial compressive load tests of two single piles and a group of four piles with diameter 800 mm and 12 m length were also conducted. The experiment results show that the bearing capacity of every single pile is 1.200 kN with settlement 6.93 mm and the group of four CSpiles is 3.200 kN with settlement 5.03 mm. The results presented in the paper illustrate that SCpile is the suitable solution for foundation construction process with low cost and saving time for high rise buildings. The result shows a capable application of soil cement piles for support of high-rise buildings.
A three meter-length cantilever beam loaded with a concentrated load at its free end is studied t... more A three meter-length cantilever beam loaded with a concentrated load at its free end is studied to determine shear stresses. In the present study, three cross sections are considered: rectangle (R); I, and T. The study presents a comparison of maximum shear stresses obtained by means of two methods: classical analytical equation derived by Collingnon, and finite element method (FEM) software. Software programs ANSYS and SAP2000 were used. The results show difference between the maximum shear stresses obtained by the analytical equation and the software, being the last is always higher. The average differences for ANSYS and SAP2000, independently of the cross section, were 12.76% and 11.96%, respectively. Considering these differences, correction factors were proposed to the classical analytical formula for each cross section case to obtain more realistic results. After the correction, the average differences decrease to 1.48% and 4.86%, regardless of the cross section shape.
The Ministry of Education in Iraq is confronting a colossal deficiency in school buildings while ... more The Ministry of Education in Iraq is confronting a colossal deficiency in school buildings while stakeholders of government funded school buildings projects are experiencing the ill effects of extreme delays caused by many reasons. Those stakeholders are particularly worried to know ahead of time (at contract assignment) the expected completion time of any new school building project. As indicated by a previous research conducted by the authors, taking into account the opinions of Iraqi experts involved with government funded school building projects, nine major causes of delay in school building projects were affirmed through a questionnaire survey specifically are; the contractor's financial status, delay in interim payments, change orders, the contractor rank, work stoppages, the contract value, experience of the supervising engineers, the contract duration and delay penalty. In this research, two prediction models (A and B) were produced to help the concerned decision makers to foresee the expected completion time of typically designed school building projects having (12) and (18) classes separately. The ANN multi-layer feed forward with back-propagation algorithm was utilized to build up the mathematical equations. The created prediction equations demonstrated a high degree of average accuracy of (96.43%) and (96.79%) for schools having (12) and (18) classes, with (R 2) for both ANN models of (79.60%) and (85.30%) respectively. It was found that the most influential parameters of both models were the ratio of the sum of work stoppages to the contract duration, the ratio of contractor's financial status to the contract value, the ratio of delay penalty to the total value of contract and the ratio of mean interim payments duration to the contract duration.
In this paper, four known analytical methods including Wang (1993), Penzien (2000), Park et al. (... more In this paper, four known analytical methods including Wang (1993), Penzien (2000), Park et al. (2009), and Bobet (2010) were Evaluated based on seismic design of circular tunnel in Tehran Metro Line 6. For this purpose, a quasi-static numerical method was applied in the framework of finite difference method (FDM) under the same assumptions. In both numerical and analytical methods, to consider the nonlinear behavior of soil, linear equivalent properties of soil derived from ground analysis were incorporated in EERA software. obtained results shown that the Park's analytical solution under various conditions of interaction between the tunnel lining and soil provides very close results to the of numerical modeling. Afterward, a comprehensive validation was performed to assess the impact of the rigidity of the surrounding ground and the maximum shear strain value. In this regard, several earthquake scenarios with different shear wave rates were used to achieve a wide range of flexibility ratio (F) and maximum shear strain. The results showed a significant difference between the results of Penzine's and Bobet's methods under the no-slip conditions and those of numerical analyses for a certain range of flexibility and shear strain ratios. In the final part of the paper, a quasi-static seismic numerical study was performed under realistic soil-structure interaction conditions to illustrate the importance of the actual interaction between the tunnel lining and surrounding soil. The results showed that the actual interaction conditions governing estimation of the axial force play a very important role. Also, it was found that Park's solution, because of the ability to consider the slip at the interface provides results very close to those of the numerical modeling. In contrast, one of the serious limitations of the other analytical methods is their inability to simulate the slip interface between the tunnel lining and soil.
Throughout history, fashion and architecture have repeated each other in terms of form and appear... more Throughout history, fashion and architecture have repeated each other in terms of form and appearance. It seems quite natural that they share not only their initial function, which is to provide shelter and protect human; but also show skills in creating space and volume beyond the two-dimensional plates and materials. In recent years, the relationship between clothing design and architecture has become more significant. Computer tools and software have changed the borders of designing each one. Buildings are more fluid and clothes are more architectural. The architectural alphabet in fashion from one hand, and on the other hand the fashion ideas and methods used in architecture as well as experiencing similar themes in both domains are among the features of these arts. The exploitation of such common points among the two areas challenges the conventional ideas and pre-defined concepts of design, putting forward new solutions and experiences for designers. In this research, some of these common ideas have been studied and how these ideas are linked within both of these domains. The method of this research is descriptive and analytical; and data are collected from documents and research materials including books, articles, photos and electronic resources. This research seeks the common ideas in architecture and fashion and their mutual interaction with each other and provides some examples in both arts. The results of this research show that architecture has an effective role in shaping fashion and the attitude to the clothing design.
Exact estimation of vibration fundamental period of structures plays a vital role in their design... more Exact estimation of vibration fundamental period of structures plays a vital role in their designing procedure. The proposition of a relatively exact expression which considers the effects of a pile group on the fundamental period of the structures was of less interest to previous researchers. This study aims to propose an analytical model and expression so as to estimate the free vibration period of the structures located on a pile group. To reach the objectives of this study, several numerical analyses has been carried out using the method of equivalent spring which takes into account the effects of soil-pile-structure interaction on the fundamental period of the structures. In the next step of the study the effects of a pile group on the fundamental period of the structures have been analyzed analytically. In this analytical study two cases have been considered for the piles which are end-bearing and floating piles. In the case of floating piles a five degrees-of-freedom analytical model and its corresponding expression have been proposed considering the soil-pile-structure system. The numerical modelling has been performed using the direct method due to the neglect of the soil in analytical expression and the results have been compared with those of the proposed analytical expression. The soil mass participation coefficient (λ) has been obtained using the discrepancy between the results of the two different methods t o modify the analytical expression. In the case of end-bearing piles an analytical model with three degrees-of-freedom and its corresponding expressions has been proposed. Then the soil has been neglected and a new analytical expression has been proposed using the mass participation coefficients adopted from other researches to calculate the fundamental period of the structures. The comparison between the results of the proposed expression and those of case and numerical studies confirms that the proposed expressions benefit from a relative accuracy and can be used as an initial criterion in designing procedure.
Countries from all over the world including Iran, consider different maximum allowable speeds to ... more Countries from all over the world including Iran, consider different maximum allowable speeds to control and maintain traffic safety on their freeways, but these actions have not been successful even with the police surveillance. Even though speeding is not the only cause of accidents, past studies indicate that speed plays a vital role in such events. Since respecting the speed limits have not prevented driving violations and traffic accidents, there's doubt among decision-makers, about the applicability and safety of these legal speed limits in different weather and traffic conditions. They think perhaps there is a need for an optimized and safe speed after doing required studies. Even in the police instructions and notifications in unfavorable weather conditions, the word " safe speed " is used more than the " legal speed " and its limit is not mentioned and its determination is assigned to drivers according to their mental and physical conditions, type of vehicle, and the weather condition. This matter leads to uncertainty for drivers in selecting the right speed.This research is intended to achieve a safe and optimized speed for freeways in Iran, by considering a reasonable adjustment which is acceptable by the drivers so that a substantial decrease in driving violations and accidents could be observed. This work is done by using models developed for predicting violations and accidents on Iran's freeways. The results indicate that by reducing the allowable speed of freeways from 125km/h to 105 km/h, a 48% and 23% reduction of violations and traffic accidents could be achieved.
This study deals with the intrinsic vulnerability of groundwater reservoirs to pollution, by the ... more This study deals with the intrinsic vulnerability of groundwater reservoirs to pollution, by the use of two models DRASTIC and GODS, this study is done by taking samples from 17 water resources of Malayer plain Aquifer area of southern Hamedan Province, Iran. 30 physicochemical parameters and heavy metals have been studied and vulnerability of this aquifer to the nitrate concentration, was determined. The study showed that results from DRASTIC were better than GODS in Assessment and Estimating groundwater vulnerability to pollution, also DRASTIC model has been corrected, and compared the ability of these two models in vulnerability zoning has been evaluated. According to high correlation between DRASTIC index and nitrate concentration, ranking and weighting of nitrate pollutant is inserted in the DRASTIC equation, and zoning map of DRASTIC method has been calibrated by nitrate concentration. By this method, vulnerability zoning is determined between very low to very high, which shows the increase of DRASTIC index by nitrate concentration. DRASTIC parameters uncertainty has affected the zoning results in this method, but its calibration with nitrate concentration, gives more accurate vulnerability results.
Nowadays, the development of construction industry is one of the development indices of countries... more Nowadays, the development of construction industry is one of the development indices of countries. On the other hand, development of construction industry is more urgent than ever with increased population and consequently, increased desire for urbanization. Considering the inadequacy of traditional and conventional systems for mass housing production, the approach to use modern industrial methods of building along with new technology and observance of the latest technical standards is critical. Therefore, the present study aimed to investigate and compare construction method of reinforced concrete cast in-situ walls and slabs with the conventional method of constructing concrete structures using MSP software. Studies show that the integrated wall and ceiling molding technique has been used since the late 1970s in the construction of high-rise residential towers. Currently, integrated wall and ceiling molding system is used as one of the methods in the construction of buildings with load-bearing wall and concrete ceiling. This method brings about improvements in quality, earthquake resistance, reduced run-time, reduced cost, quick return on investment, saving on materials consumption, reduced labor, eco-friendliness, sustainability and longer durability, reduced resource consumption, integrated structure, fire resistance, high flexibility, and employee safety.
Texture coefficient is one of the most influential parameters in rock engineering specifications ... more Texture coefficient is one of the most influential parameters in rock engineering specifications in various projects including drilling, cutting, permeability of all-section drilling devices, etc. Meanwhile, investigating and forecasting the energy consumption of saw cutters are one of the most important factors in estimating the cutting costs. The present study aims to investigate the relationship between rock texture characteristics and the amount of energy consumption of the gang saw machine in the process of cutting carbonate rocks. To evaluate the effects of texture on the rocks' engineering specifications, 14 carbonate rock samples were studied. A microscopic thin section was made from each rock specimen. Then, five digital images were taken from each section under a microscope and the values of area, environment, the largest diameter and the smallest diameter of all grains in each image were determined. Using these specifications, the coefficient of texture of all rock samples was calculated and the relationship between the texture coefficient and the rate of energy consumption of the gang saw machine was investigated for the studied samples. The study results indicated that there was a significant relation between the texture coefficient and energy consumption rate in the three groups of carbonate rocks.
One of the main causes of bridge collapse may be flood flow scour near piers. Several experimenta... more One of the main causes of bridge collapse may be flood flow scour near piers. Several experimental and local field investigations were carried out to study scour depth. However, existing empirical equations do not commonly provide accurate scour prediction due to the complexity of the scour process. Physical and economic considerations often lead to bridge foundation constructs which included a pier column based on a pile cap supported by an array of piles. Piers with this configuration are referred to as complex piers. A few studies have been done on complex bridge pier scour depth estimation. Such efforts may be classified into theoretical and empirical equations. This paper investigates local scour around complex bridge piers by using harmony search algorithm under clear water conditions. Statistical indices such as the coefficient of determination (R2), root mean square error (RMSE), mean absolute error (MAE), mean absolute percentage error (MAPE), and bias were used to evaluate the performance of these methods. By designing laboratory tests, 82 experimental data points were measured by authors. Also 615 experimental data sets with the same measured experimental conditions were collected from published literature and used for optimization. The results show that the developed HS model can predict scour depth better than other equations according to statistical indices.
Effectively enhancing buildings' adaptability, extending their service lives, and reducing constr... more Effectively enhancing buildings' adaptability, extending their service lives, and reducing construction wastes has become a crucial issue in the construction industry. As the transformation of the socioeconomic structure and diversification of user demands has grown, occupants in residence may have various needs in different stages, rethinking a sustainable and flexible living space has received substantial focus. " Open building (OB) " is an innovative method to accommodate various changeable occupant spaces, decrease the waste caused by space adjustment and reduce maintenance costs. Although the concept of OB is beneficial for sustainable built environments, the promotion of OB in Taiwan is constrained. One of the obstacles is that the OB approach is partly in conflict with the current building regulations. Without legally developed policies, developers are reluctant to supply OB housing in the market; occupants are unwilling to take the risk of implementing OB approaches in renovation. This study applied a Kano two-dimensional quality model to classify and prioritize OB regulation suggestions proposed by experts in Taiwan. A series of forums and interviews were conducted to develop OB regulations. Barriers and challenges will be discussed for further OB development that can be applied to improve building longevity, adaptability, and sustainability.
The goal of this study was twofold; first analyze the patterns of water consumption in Lagos, Nig... more The goal of this study was twofold; first analyze the patterns of water consumption in Lagos, Nigeria and use them in a System Dynamics (SD) model to make projections about future demand. The second part used remote sensing to quantify the contribution of extensive land use/cover change to urban flooding. Land use/cover dynamics over the past decade was analyzed using satellite imagery provided by Landsat Thematic Mapping (TM). Unsupervised classification was performed with false color composite using the Iterative Self-Organizing Data Analysis (ISODATA) technique in a Geographic Information Systems (GIS). The study area was divided into four different land use types during image classification: bare land, built-up area, water bodies, and vegetation. For water demand, two different scenarios of population growth including 5.5% and 2.75 % annual increase were considered. The results showed that water demand dropped by 67% of its current value when losses in distribution were reduced by 20% and population annual growth rate kept at 2.75% over the study period. Bare land and water bodies lost 1.31% and 1.61% of their current area respectively while built-up area grew by 1.11%. These changes in land use/cover changes led to a 64% increase in average surface runoff, mostly attributable to increasing surface imperviousness and the absence of an adequate urban drainage system.
Considering the increasing population growth and the rapid growth of urbanization and pollution i... more Considering the increasing population growth and the rapid growth of urbanization and pollution in the environment, providing zoning maps and urban engineering geology seem to be important. The rapid construction growth of cities, as well as the confrontation with events such as earthquakes and failure to observe the geological and geotechnical issues, has caused many engineering problems. The use of geophysical methods not only cannot lonely provide us a complete and comprehensive information on the geotechnical conditions of the earth but also has many disturbances in urban areas, and its use in urban centers is almost impractical. Therefore, it seems that the best way of examining and interpreting the geotechnical characteristics of a site, especially in urban areas, is the use of suspicious data. Therefore, performing geotechnical studies and geotechnical zoning can be useful for retrofitting buildings and engineering structures and reducing their risks. Hence, zoning studies are conducted in this research in order to better recognize the technical soil status for safe construction due to rising the population of Tehran in recent decades and the concentration of population in certain areas of Tehran, especially in the eastern and western regions (districts 4 and 22). In this study, different geotechnical field tests such as standard penetration test (SPT), cone penetration test (CPT) were used to estimate parameters such as adhesion coefficient (C), internal friction angle (í µí¼), Young modulus (E). Other common experiments with conventional geophysical experiments, such as in good experiments, refractive and CSSW were applied to estimate geophysical parameters of bedrock depth and shear wave velocity for zoning these areas.
During the service life, the asphalt pavement layers subjected to various detrimental types of di... more During the service life, the asphalt pavement layers subjected to various detrimental types of distresses such as permanent deformation, fatigue, stripping and shoving which lead to the complete failure of the pavement. In Iraq roads the permanent deformation (rutting) is the importance distresses which cause impact on the highway performance and reducing the service life of the pavement. The research aims to utilize locally available materials and environment friendly as reinforcement layer. The program of this research include preparing asphalt mixes represent surface layer by using locally available materials and using the reinforcement layer which made of reed. The permanent deformation test has been done with three temperatures (40˚C, 50˚C and 60˚C) and four locations of the reed mats. The test results of the wheel-Track for the rutting measurement showed that the rut depth decrease in reinforcement layers as compared with unreinforcement layers for all temperature testing. The reed netting embedded bottom and middle of wearing layer has the best amount of improvement (75%, 84% and 85%).
This study aimed to evaluate the possibility of reducing the thickness of asphalt layer as a nove... more This study aimed to evaluate the possibility of reducing the thickness of asphalt layer as a novel solution for the high density of asphalt layer incorporated with steel slag aggregate, which increase the cost of transportation. Mechanistic-Empirical Pavement Design (MEPDG) approach was employed to evaluate the benefits of introducing polyvinyl alcohol fiber in terms of reducing the thickness of asphalt layer as well as the extension service life of asphalt layer. On the other hand, the correlation between creep strain slope (CSS) and secant creep stiffness modulus (SCSM) were assessed to provide a better evaluation and understanding concerning of the outputs of the dynamic creep test. The findings of this study showed that introducing polyvinyl alcohol fiber into the mixtures at the optimum content (0.5 kg/ton) have reduced the thickness of asphalt layer by approximately 10%. Additionally, polyvinyl alcohol fiber has increased the performance of the asphalt mixtures concerning of resilient modulus and dynamic creep. Furthermore, the correlation between CSS and SCSM was strong, which indicates that evaluation of permanent deformation using CSS and SCSM parameters provides better actual assessment than accumulation strain.
Crack is one of the most common defects observed in reinforced concrete (RC) structures. An initi... more Crack is one of the most common defects observed in reinforced concrete (RC) structures. An initial crack will lead to severe changes in the stress state when the structure subjected to blast loadings. Target on acquiring the dynamic data, a finite element method is applied to simulate the response of cracked RC slab subjected to blast loading. The theoretical results of damage distribution and mid-span deflection of normal specimens are first compared with experimental test, which indicates that the dynamic behaviour of RC slab under blast loading can be well predicted by the finite element model. Then blast responses of cracked RC slabs with varied crack parameters (e.g. orientation, width and depth) are systematically studied. Results show that damage of the cracked slab initiates from the initial crack tip of the bottom surface, and then it propagates quickly with cracks found in the support areas on the top surface. In addition, the existence of initial cracks in the RC slab make it subject to more serious damages than the normal RC slab under the same explosive loads, as well as a short reacted failure time. Moreover, variations of crack parameters have slight influences on the distributions of cracked RC slab.
This paper presents a technique for irregular plate and regular dam damage detection based on com... more This paper presents a technique for irregular plate and regular dam damage detection based on combination of wavelet with adoptive neuro fuzzy inference system (ANFIS). Many damage detection methods need response of structures (such as the displacements, stresses or mode shapes) before and after damage, but this method only requires response of structures after damage, otherwise many damage detection methods study regular plate but this method also studies irregular plate. First, the structure (irregular plate or regular dam) is modelled by using ANSYS software, the model is analysed and structure's responses with damage are obtained by finite element approach. Second, the responses at the finite element points with regular distances are obtained by using ANFIS. The damage zone is represented as the elements with reduced elasticity modules. Then these responses of structures are analysed with 2D wavelet transform. It is shown that matrix detail coefficients of 2D wavelet transform can specified the damage zone of plates and regular dams by perturbation in the damaged area.
Excavator is heavy equipment that usually used in construction and mining works. Bucket teeth whi... more Excavator is heavy equipment that usually used in construction and mining works. Bucket teeth which are located in the tip of bucket excavator are used for digging works. They are easily damaged by direct contact with the media. One of the material used in bucket teeth excavator is mild carbon steel that has carbon content between 0.33%-0.5%. However, the hardness value of this material is not yet meets the standard of bucket teeth excavator so the optimum hardness value based on its heat treatment should be known. Besides that, its tensile, impact strength, and micro structure in optimum condition will also know. Optimization method was done through Taguchi experimental design with L9 orthogonal and ANOVA (Analysis of Variance). Factors or parameters in this research were heating temperature, holding time, quenching media, and tempering temperature. In this experiment, nine specimens of mild carbon steel were tested by different heating temperatures (850 o C, 875 o C, 900 o C), different holding times (60, 90, and 120 minutes), different quenching medias (oil, water, and salt water), and different tempering temperatures (250 o C, 450 o C, 650 o C). Calculation of Taguchi method and confirmation experiment showed that the optimum parameters of hardness are 875 o C heating temperature, 60 minutes holding time, water quenching media, and 250oC tempering temperature. Meanwhile, ANOVA test showed a result that the four factors had an effect on the bucket teeth excavator hardness.
Lightweight foamed concrete is a type of concrete characterized by light in self-weight, self-com... more Lightweight foamed concrete is a type of concrete characterized by light in self-weight, self-compaction, self-leveling, thermal isolation, and a high ratio of weight to strength. The advantages of GFRP bars include lightweight, high longitudinal tensile strength, non-conductivity, and resistance to corrosion. This study investigated the behavior of LWFC beams reinforced with GFRP bars under flexural loading. A total of four reinforced concrete beams were cast, where it consisted of two LWFC beams and two normal weight concrete beam which acted as control specimen. One of the lightweight foamed concrete beams and the normal concrete beams is reinforced with two GFRP bars and the other reinforced with two steel bars. All beams were designed with singly reinforced of two bars of diameter 12 mm. The LWFC beams were with cement to sand ratio (1:1) and average dried density of 1800± kg/m 3. The main variables considered in this study was type of concrete and type of reinforcement. The flexural parameters investigated are ultimate load, crack width, ductility, deflection and stiffness. The lightweight foamed concrete beam reinforced with GFRP bars showed deflection and crack width greater than in beam reinforced with steel bars due to the low modulus of elasticity of GFRP bars.
This paper presents the experimental study of Soil-Cement Pile (SCpile) by wet mixing method in s... more This paper presents the experimental study of Soil-Cement Pile (SCpile) by wet mixing method in sandy soils, with the typical project at An Trung Complex apartment, Da Nang city, Vietnam. With the characteristic of soil layers is sandy soil, the strength of laboratory stabilized soils with the amount of cement from 150300 kg/m 3 was determined. Simultaneously, the authors also performed the experiments of 20 test piles collected from the site which has cement content about 280 kg/m 3 and the unconfined compressive strength qu= (4.56.0) MPa. After that, a full-scale model static axial compressive load tests of two single piles and a group of four piles with diameter 800 mm and 12 m length were also conducted. The experiment results show that the bearing capacity of every single pile is 1.200 kN with settlement 6.93 mm and the group of four CSpiles is 3.200 kN with settlement 5.03 mm. The results presented in the paper illustrate that SCpile is the suitable solution for foundation construction process with low cost and saving time for high rise buildings. The result shows a capable application of soil cement piles for support of high-rise buildings.
A three meter-length cantilever beam loaded with a concentrated load at its free end is studied t... more A three meter-length cantilever beam loaded with a concentrated load at its free end is studied to determine shear stresses. In the present study, three cross sections are considered: rectangle (R); I, and T. The study presents a comparison of maximum shear stresses obtained by means of two methods: classical analytical equation derived by Collingnon, and finite element method (FEM) software. Software programs ANSYS and SAP2000 were used. The results show difference between the maximum shear stresses obtained by the analytical equation and the software, being the last is always higher. The average differences for ANSYS and SAP2000, independently of the cross section, were 12.76% and 11.96%, respectively. Considering these differences, correction factors were proposed to the classical analytical formula for each cross section case to obtain more realistic results. After the correction, the average differences decrease to 1.48% and 4.86%, regardless of the cross section shape.
The Ministry of Education in Iraq is confronting a colossal deficiency in school buildings while ... more The Ministry of Education in Iraq is confronting a colossal deficiency in school buildings while stakeholders of government funded school buildings projects are experiencing the ill effects of extreme delays caused by many reasons. Those stakeholders are particularly worried to know ahead of time (at contract assignment) the expected completion time of any new school building project. As indicated by a previous research conducted by the authors, taking into account the opinions of Iraqi experts involved with government funded school building projects, nine major causes of delay in school building projects were affirmed through a questionnaire survey specifically are; the contractor's financial status, delay in interim payments, change orders, the contractor rank, work stoppages, the contract value, experience of the supervising engineers, the contract duration and delay penalty. In this research, two prediction models (A and B) were produced to help the concerned decision makers to foresee the expected completion time of typically designed school building projects having (12) and (18) classes separately. The ANN multi-layer feed forward with back-propagation algorithm was utilized to build up the mathematical equations. The created prediction equations demonstrated a high degree of average accuracy of (96.43%) and (96.79%) for schools having (12) and (18) classes, with (R 2) for both ANN models of (79.60%) and (85.30%) respectively. It was found that the most influential parameters of both models were the ratio of the sum of work stoppages to the contract duration, the ratio of contractor's financial status to the contract value, the ratio of delay penalty to the total value of contract and the ratio of mean interim payments duration to the contract duration.
In this paper, four known analytical methods including Wang (1993), Penzien (2000), Park et al. (... more In this paper, four known analytical methods including Wang (1993), Penzien (2000), Park et al. (2009), and Bobet (2010) were Evaluated based on seismic design of circular tunnel in Tehran Metro Line 6. For this purpose, a quasi-static numerical method was applied in the framework of finite difference method (FDM) under the same assumptions. In both numerical and analytical methods, to consider the nonlinear behavior of soil, linear equivalent properties of soil derived from ground analysis were incorporated in EERA software. obtained results shown that the Park's analytical solution under various conditions of interaction between the tunnel lining and soil provides very close results to the of numerical modeling. Afterward, a comprehensive validation was performed to assess the impact of the rigidity of the surrounding ground and the maximum shear strain value. In this regard, several earthquake scenarios with different shear wave rates were used to achieve a wide range of flexibility ratio (F) and maximum shear strain. The results showed a significant difference between the results of Penzine's and Bobet's methods under the no-slip conditions and those of numerical analyses for a certain range of flexibility and shear strain ratios. In the final part of the paper, a quasi-static seismic numerical study was performed under realistic soil-structure interaction conditions to illustrate the importance of the actual interaction between the tunnel lining and surrounding soil. The results showed that the actual interaction conditions governing estimation of the axial force play a very important role. Also, it was found that Park's solution, because of the ability to consider the slip at the interface provides results very close to those of the numerical modeling. In contrast, one of the serious limitations of the other analytical methods is their inability to simulate the slip interface between the tunnel lining and soil.
Throughout history, fashion and architecture have repeated each other in terms of form and appear... more Throughout history, fashion and architecture have repeated each other in terms of form and appearance. It seems quite natural that they share not only their initial function, which is to provide shelter and protect human; but also show skills in creating space and volume beyond the two-dimensional plates and materials. In recent years, the relationship between clothing design and architecture has become more significant. Computer tools and software have changed the borders of designing each one. Buildings are more fluid and clothes are more architectural. The architectural alphabet in fashion from one hand, and on the other hand the fashion ideas and methods used in architecture as well as experiencing similar themes in both domains are among the features of these arts. The exploitation of such common points among the two areas challenges the conventional ideas and pre-defined concepts of design, putting forward new solutions and experiences for designers. In this research, some of these common ideas have been studied and how these ideas are linked within both of these domains. The method of this research is descriptive and analytical; and data are collected from documents and research materials including books, articles, photos and electronic resources. This research seeks the common ideas in architecture and fashion and their mutual interaction with each other and provides some examples in both arts. The results of this research show that architecture has an effective role in shaping fashion and the attitude to the clothing design.