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.
Rahim Hajibagheri; Amirhossein Bazaee; Roozbeh Aghamajidi
Abstract
The phenomenon of flood, in spite of all its complexities, can be studied and appropriate solutions can be sought to control and reduce its damage and even economic exploitation of floods. On the other hand, before constructing any hydraulic structure such as dams, overflows, diversion channels, temporary ...
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The phenomenon of flood, in spite of all its complexities, can be studied and appropriate solutions can be sought to control and reduce its damage and even economic exploitation of floods. On the other hand, before constructing any hydraulic structure such as dams, overflows, diversion channels, temporary dams, etc., it is necessary to have the information of maximum possible flood and flood hydrograph with different return periods in order to estimate the magnitude of different floods and predicted the maximum height of the river flood zone, the maximum area and width of the river flood in different areas, the maximum flow velocity, changes in shear stress, flood volume, changes in landing number and hydraulic radius, etc. flood routing and zoning operations or quantifying river confluence for flood alert systems. in this study, by selecting the case of Sivand river in fars province in the specified time period, flood frequency analysis was performed with the help of Smada and Easyfitt software and the maximum flood discharge was determined with different return periods. then, by selecting tangbolaghi hydrometric station as the representative station of Sivand river, hydraulic flood routing and zoning operations were attempted by Mike11 computer model.
Saeed Radmanesh; Amirhossein Bazaee; Roozbeh Aghamajidi
Abstract
Overflows are generally installed to drain excess water or floods that the volume of the tank can not store. In diversion dams, overflow is used to bypass or divert current in excess of system capacity. Demolition of many dams occurs due to incorrect design or insufficient overflow capacity. Proper spill ...
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Overflows are generally installed to drain excess water or floods that the volume of the tank can not store. In diversion dams, overflow is used to bypass or divert current in excess of system capacity. Demolition of many dams occurs due to incorrect design or insufficient overflow capacity. Proper spill design is more important in gravel earthen dams than in concrete dams. because the probability of destruction of earthen and gravel dams due to water passage is much higher than concrete dams. In the present study, a comprehensive review of the types of applied overflows based on effective dynamic and kinematic parameters was performed. Also, definitions and summaries of different types of free overflows were shot, siphon, stepped, congressional, lateral, tunnel, circular crown, peak, lotus or tulip. Then, the mechanism of vortex formation was introduced and an overflow appropriate to this phenomenon was introduced. The results of these cases showed that the application of lotus or tulip overflow in flood areas with high discharge has better performance.
Saeed Radmanesh; Amirhossein Bazaee; Roozbeh Aghamajidi
Abstract
In general, Spillway are divided into two types linear and non-linear, among which, the Morning Glory overflow is a non-linear overflow. In some cases, the hydraulic performance of the overflow is affected by the immersion coefficient and its hydraulic efficiency is reduced and affected by the immersion. ...
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In general, Spillway are divided into two types linear and non-linear, among which, the Morning Glory overflow is a non-linear overflow. In some cases, the hydraulic performance of the overflow is affected by the immersion coefficient and its hydraulic efficiency is reduced and affected by the immersion. Structures such as vortex breakers (separators of flow lines to increase transit efficiency) and to increase overflow efficiency should be used. In this regard, using dimensional analysis by Buckingham method, it was determined that the overflow coefficient of the overflow is a function of variables such as vortex breaker height ratio (Hvb / Rs), vortex breaker thickness ratio (Tvb / Rs), number of vortex breakers (VB) and overflow shape factor ( Sf) is. The experiments of the present study were performed on a square flume with dimensions of 2.5 × 2.5 and a height of 2 m 0.20 1 1.05 /0 1.05 m3. The results showed that the overflow of stepped Morning Glory (12 steps) and vortex breaker with high height and 6-array arrangement has a much better and more suitable performance compared to non-stepped overflow and has increased the permeability coefficient by 23%.
Roozbeh Aghamajidi; Rahim Hajibagheri
Abstract
Increasing study and research on the components of concrete structures has led to the availability of materials, the use of which in turn has been able to have a tremendous impact on concrete production. Concrete is undoubtedly the most important building material, the production and consumption of which ...
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Increasing study and research on the components of concrete structures has led to the availability of materials, the use of which in turn has been able to have a tremendous impact on concrete production. Concrete is undoubtedly the most important building material, the production and consumption of which is increasing day by day and it is used in almost all structures. The performance of cement as one of the main components of concrete products has always been considered and with the increasing development of Iran's cement industry in terms of quantity in the production of cement, cement quality control by examining physical and chemical properties is very important. In this study, we tried to investigate the factors affecting the strength of hydrated cement used in concrete structures in Shiraz and the results indicate a decrease in concrete strength due to increasing the ratio of water to cement and also C3S and C2S are the two main compounds causing cement strength are hydrated.
saeed radmanesh; roozbeh aghamajidi
Volume 3, Issue 2 , May 2021, , Pages 32-47
Abstract
Flexural reinforcement of reinforced concrete beams with composite materials is one of the most common methods of structural reinforcement. Composite materials have several advantages such as ease of implementation, easy access, relatively low cost, increased bearing capacity, low weight, etc., but despite ...
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Flexural reinforcement of reinforced concrete beams with composite materials is one of the most common methods of structural reinforcement. Composite materials have several advantages such as ease of implementation, easy access, relatively low cost, increased bearing capacity, low weight, etc., but despite all these advantages, the use of these materials also has disadvantages, which can be Premature and sudden bending failure in beams reinforced with these materials, which occurs due to premature rupture of composite materials or even deterioration of the joint area due to lack of attention to the stability of epoxy adhesive from the concrete surface in the tensile zone of the beam, noted. In this paper, by designing a computational program with Abacus software, 7 examples of reinforced concrete beam reinforcement design with GFRP rebar by near-surface installation method (NSM) and its integration with various FRP sheet enclosure cases taken from a This is a laboratory study, an attempt was made to prevent premature failure of the reinforced beam and to be able to use the maximum capacity of GFRP rebar. It is noteworthy that in modeling this reinforcement design with composite materials, the effect of ultimate adhesion resistance and failure or deterioration of epoxy adhesive between NSM rebar and concrete surface is important, so in this modeling of the joint area which is epoxy adhesive modeling and its behavior Has been examined. The use of this reinforcement method with four NSM rebars and FRP sheets increased the final bearing capacity by more than 60% compared to conventional reinforced concrete beams.
