Research Article
S.Mohamad Sadegh Rasooli; Amirhossein Bazaee; Roozbeh Aghamajidi
Abstract
Affected by numerous elements, the estimation of manning's roughness coefficient is of great importance and sensitivity. In the present study a reach of 56 km from beshar river in kohgiluyeh and boyer-ahmad province was studied. The selected reach was divided into 12 sub-reaches based on similar characteristics. ...
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Affected by numerous elements, the estimation of manning's roughness coefficient is of great importance and sensitivity. In the present study a reach of 56 km from beshar river in kohgiluyeh and boyer-ahmad province was studied. The selected reach was divided into 12 sub-reaches based on similar characteristics. Experimental and quasi-experimental methods, tables, and cowan's method were used to estimate manning's coefficient. The estimation results were compared with stage-discharge rating curves from two hydrometric stations located in the selected reach. The ‘inverse solution’ was proved to be the best method to estimate manning's coefficient in the river under study followed by bruschin and cowan's method with an average error of 0.237 and 0.241, respectively.
Research Article
Fahime Mohamadpour; Ali Ghorbani
Abstract
The most strategic industry of any country is its construction industry, which has always been the focus of different governments. However, the weak group (the worker) is always disrespected and its rights are ignored. The researches of the last few years show that if special attention not paid to the ...
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The most strategic industry of any country is its construction industry, which has always been the focus of different governments. However, the weak group (the worker) is always disrespected and its rights are ignored. The researches of the last few years show that if special attention not paid to the worker, there will be many disturbances to the environmental conditions of the construction project. Irreparable defects that should be paid special attention to its legal, moral and cultural dimensions. Therefore, the goal of this project is to adopt the best strategy for increasing the productivity of the worker and ultimately the construction site. In this research the correlational research method as well as the ANP technique have used. According to the results the construction project has been qualitatively improved when the physical development, the working class and the guarantee of their rights paid attention. By examining the variables of research and placement in the ANP decision-making network, the guarantee of worker's rights is the most important parameter for the future development of the construction project.
Research Article
Alireza Doroudian Homayouni; Abbas Ghasemi
Abstract
The direct displacement-based design method introduced and expanded by Priestley et al. is one of the functional methods that has the ability to replace the force-based design method. Estimation of hysteresis damping and displacement of yielding are among the key parameters of this method, the error ...
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The direct displacement-based design method introduced and expanded by Priestley et al. is one of the functional methods that has the ability to replace the force-based design method. Estimation of hysteresis damping and displacement of yielding are among the key parameters of this method, the error in their estimation leads to the overall error in the estimation of base shear. In this study, 10 bending steel frames with vestibular braces and short and medium zippers have been investigated and evaluated for tremors. With a wide range of analyses, including non-linear dynamic analyses of time history based on natural accelerometers, as well as wear analysis based on different patterns, yielding displacement, damping, effective cycle time, secant cycle time and base shear of the steel bending frames with the above-mentioned hip brace and zipper are analysed. And the relationships presented in the DBD regulations have been verified. Finally, by proposing relationships for damping and displacement of yielding, in relation to improving the performance of the direct design method based on displacement in steel bending frames, it has been done as follows. Given that increasing damping, it underestimates the forces applied to the structure. It seems that Priestley's formula is presented with a higher reliability factor and results in the design of harder and heavier structures, in terms of the amount of steel consumption. The amount of damping is not very sensitive to the changes in the number of openings and in the worst case, the damping has a difference of 3% with the increase in the number of openings.
Research Article
AliMohammad Sazegar; roozbeh aghamajidi; mehdi rezaei
Abstract
The use of rubber crumb as an additive in the production of concrete has been studied as a means of improving compressive strength while also addressing the environmental impact of non-degradable ingredients. In this research, the effects of adding 5%, 7.5%, and 10% rubber crumb by weight to 2% cement ...
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The use of rubber crumb as an additive in the production of concrete has been studied as a means of improving compressive strength while also addressing the environmental impact of non-degradable ingredients. In this research, the effects of adding 5%, 7.5%, and 10% rubber crumb by weight to 2% cement were analyzed. The results showed that the addition of 5% rubber crumb resulted in the highest increase in compressive strength, with a 45% increase at 7 days and 8% increase at 28 days compared to the control concrete. However, the addition of 10% rubber crumb resulted in a decrease in compressive strength, with a 3% reduction at 28 days, 5% reduction at 90 days, and 1% reduction at 120 days. The price of self-compacting concrete also increased by 16.4%, 20.5%, and 24.5% for the 5%, 7.5%, and 10% rubber crumb samples, respectively. Overall, this research suggests that the use of rubber crumb as an additive in concrete production can potentially improve compressive strength while also contributing to environmental sustainability, though the optimal percentage of rubber crumb for this purpose may vary.
