Assessment of Groutability and Cement Take in Khersan II Dam Site
Abdollah
Sohrabi-Bidar
School of Geology, College of Sciences, University of Tehran, Tehran.
author
Morteza
Mozafari
School of Geology, College of Sciences, University of Tehran, Tehran.
author
Abbas
Zolfaghari
Department of Geology, Faculty of Sciences, Tarbiat Modares University.
author
Ahmad
Rastegarnia
Department of Geology,, Faculty of Sciences, Ferdowsi University.
author
text
article
2021
per
Cement grouting is a common method for sealing and consolidating dam foundations. Since grouting is a cost and time- consuming process, understanding the amount of cement consumption is essential to estimate the cost of any dam construction. The geological setting is one of the main factors affecting the amount of cement take. In this paper, an attempt has been made to investigate the relation between the amount of cement take and the values of Rock Quality Designation (RQD), permeability, joint spacing, and joint aperture, measured in pilot holes drilled at the Khersan II Dam site (west Iran). The amount of cement take shows a direct relation with the values of permeability and joint aperture but presents a reverse relation with the values of RQD and joint spacing. Among the mentioned parameters, the Lugeon value has the highest correlation with cement consumption, however, poor correlation indicates the influence of other factors. To reduce the influence of other factors, the values of cement take were normalized to the injection pressure and then its correlation with the mentioned parameters was investigated again. Results show a significant improvement, especially between the normalized cement take and Lugeon values, resulted in at least the coefficient of determination of 0.7. After validation, the presented equation could be used to estimate the value of cement consumption at similar dam sites.
Civil Infrastructure Researches
University of Qom
2783-140X
6
v.
2
no.
2021
1
12
https://cer.qom.ac.ir/article_1793_7a2cb2400854d284be697ef5b74d018c.pdf
dx.doi.org/10.22091/cer.2021.6560.1227
Investigation of the Effect of Wave Height, Period and Spectrum on the Layout of Breakwaters (Case Study: Brizak Port)
Hamid
Heidary-Torkamani
Assistant Professor, Faculty of Civil Engineering, Sahand University of Technology, Tabriz, Iran
author
Mohammad Hadi
Moeini
PhD, coastal Eng., Pouya Tarh Pars Consulting Engineers Company, Tehran, Iran
author
text
article
2021
per
Breakwaters are among the most expensive structures in port infrastructure and therefore the optimal design of their layout to form a port basin is very important. Nowadays, in most engineering activities, the BW (Boussinesq Wave) module of the Mike21 software package is used to study and analyze the tranquillity of the port basin or to achieve the wave diffraction pattern inside the port basin. This study aims to investigate the sensitivity of the diffraction coefficients obtained from the BW model to the height, period, and type of spectrum of the incident wave. For this purpose, Brizak port has been selected for the case study and in several numerical models, the height, period and type of input wave spectrum in a specified range have been changed. In each of the models, the diffraction coefficients in a specific location are extracted and the trend of its changes is investigated. According to the results, increasing the wave period increases the diffraction coefficients in the basin while increasing the wave height reduces the diffraction coefficient.
Civil Infrastructure Researches
University of Qom
2783-140X
6
v.
2
no.
2021
13
23
https://cer.qom.ac.ir/article_1807_799ca8a276a56aef232b18e0ad2519e2.pdf
dx.doi.org/10.22091/cer.2021.6630.1231
Laboratory Study of Reinforce Slop Behavior in Unsaturated Conditions
Behnam
Mehdipour
Department of Civil Engineering, Najafabad Branch, Islamic Azad University, Najafabad, Iran.
author
Bahram
Nadi
Department of Civil Engineering, Najafabad Branch, Islamic Azad University, Najafabad, Iran.
author
Hamid
Hashemalhosseini
Civil Engineering Group, Is-fahan university of technol-ogy, Isfahan, Iran
author
Masuod
Mirmohammadsadeghi
Departeman of Water and Natural Environment, Isfahan Higher Education and Research Institute (IHEARI); Mimistry of Energy, Isfahan, Iran.
author
text
article
2021
per
Construction of road foundations or embankments on soft soil bed, due to bearing capacity, usually causes bed rupture with high subsidence. Soil reinforcement using geocell has been proposed by various researchers as a suitable solution. In the present study, experiments have been performed to investigate the behavior of armed slopes by changing the geocell position as well as the change in the percentage of soil moisture. A total of seven laboratory samples were designed and built, and the test program was designed according to two variables. These two variables are reinforcement (geocell) and moisture content. For moisture content, the values of 10%, 15%, and 20% were considered, and the geocell was examined in both the middle, and end modes of the work. The results show the positive performance of Geocell in increasing shear strength, load-bearing and flexural strength, and finally reducing displacement and increasing gable stability. The positive effect of geocell presence can be expressed according to the triple action mechanism of geocell in the reinforced soil mass. The results show that with increasing soil suction with the location of the geocell layer is constant, the displacement changes are reduced by about thirty percent, but by changing the location of the geocell layer (u/h=1 to u/h=0.5) in constant moisture, the amount decreases. Settlement and displacement is about fifteen percent.
Civil Infrastructure Researches
University of Qom
2783-140X
6
v.
2
no.
2021
25
37
https://cer.qom.ac.ir/article_1817_cb455d2c093e47ea9174e7f68cc5c7fa.pdf
dx.doi.org/10.22091/cer.2021.6444.1234
Performance Investigation of Modified Bitumen With Ethylene-Vinyl Acetate Polymer and Rubber Powder by Performing Classical and Superpave Tests
Behrooz
Damyar
Road Maintenance and Transport Organization, Iran
author
Mohamad Hosein
Dehnad
Department of Civil Engineering, University of Qom, Qom, Iran
author
Hosein
Zanjirani Farahani
Assistant Professor, Department of Civil Engineering, Tafresh University, Tafresh, Iran
author
text
article
2021
per
In this study, ethylene vinyl acetate (EVA) polymer and rubber powder were used as 85/100 bitumen modifiers. First, classical bitumen tests including penetration grade and softening point were performed on the samples and improvement of bitumen base properties was observed. Then, in order to evaluate the performance of modified bitumen at high temperature and compare it with the behavior of base bitumen, the Superpave protocol was followed. In this way, dynamic shear rheometer (DSR) test was performed and G*/sinδ index was examined on bitumen samples before and after aging. In addition, the bending beam rheometer (BBR) test was performed to evaluate the low temperature behavior of the modified bitumen according to the SHRP standard based on the creep stiffness and creep rate indices. The results showed that the combination of used additives improves the performance properties of bitumen at high temperature and also at low temperature compared to base bitumen. Based on the BBR test, 3% EVA polymer and 4% rubber powder, with a 12% reduction in creep stiffness in this composition, were selected the optimal values for the mixture.
Civil Infrastructure Researches
University of Qom
2783-140X
6
v.
2
no.
2021
39
48
https://cer.qom.ac.ir/article_1833_3953ea67ed113ea930cbb135c037c09d.pdf
dx.doi.org/10.22091/cer.2021.6588.1229
Effect of High-Strength Materials on Axial Capacity of CFT Columns
Masoud
Ahmadi
Department of Civil Engineering, Ayatollah Boroujerdi University, Boroujerd, Iran
author
Mir Rahim
Musavi
Department of Civil Engineering, Ayatollah Boroujerdi University, Boroujerd, Iran
author
text
article
2021
per
The review of existing codes and standards revealed that the design provisions for CFT members with high strength materials are still limited. This paper addresses this gap and suggests simple design equations for high strength square CFT columns using a three-step approach. The first step consists of collecting the experimental database of high-strength square composite column tests from the literature and assessing the possibility of developing the design equations for high-strength CFT columns. The second step consists of developing a nonlinear model for calculating the capacity of high-strength CFT columns using a large number of experimental data by applying gene expression programming. The third step consists of assessing the performance of the proposed relation using the common and modified coefficient of determination (R and rm), root-mean-square error (RMSE), mean absolute percentage error (MAPE), and gradients of regression lines (k and k’). An analysis is also carried out to propose a strength reduction factor (ϕ) for the proposed design equation. The results demonstrated that the proposed model has acceptable efficiency in the range of the experimental database parameters, and the suggested relation can be utilized for the pre-design of high-strength CFT columns.
Civil Infrastructure Researches
University of Qom
2783-140X
6
v.
2
no.
2021
49
66
https://cer.qom.ac.ir/article_1834_a5af3931ca30aaab9745506061591eea.pdf
dx.doi.org/10.22091/cer.2021.6837.1239
Strength Characteristics of High Plasticity Clay Sub-grade Soil Stabilized with Ground Granulated Blast Furnas Slag, Fly-Ash and Diatomite
Kourosh
Mirzaei
M.S Student, Department of Civil Engineering, Sirjan University of Technology, Sirjan
author
Ali Reza
Ghanizadeh
Associate Professor at Faculty of Civil and Environmental Engineering, Sirjan University of Technology, Sirjan, Iran.
author
Somayeh
Bakhtiari
Assistant Professor, Department of Civil Engineering, Sirjan University of Technology, Sirjan
author
text
article
2021
per
High plasticity clay soil is one of the soils that can be found in most regions of Iran. This soil is known as a problematic soil and as subgrade soil for transportation infrastructures, its characteristics must be improved. The purpose of this study is to evaluate the strength characteristics of high plasticity clay soil stabilized with industrial waste, which in addition to soil stabilization, also has environmental benefits. In this research, steel furnace slag, fly ash and diatomite have been used as stabilizer agents. Stabilization was performed using with 10, 20 and 30% of stabilizer agents by dry weight of soil and samples were compacted at optimum moisture content. In the present study, compaction as well as unconfined compressive strength (UCS) were conducted to compare the strength parameters of soil before and after stabilization. The results showed that the steel furnace slag had a much better performance as a stabilizer than fly ash and diatomite. Samples stabilized with 10% of steel furnace slag with a UCS of 2.16 MPa has a better performance in comparison with other stabilized samples and is the optimum sample. This sample shows a 3.92 times increase in UCS compared to the untreated clay soil. Treated samples with 30% of fly ash and 30% of diatomite with UCS of 0.9 and 1.03 MPa, show 49% and 88% increase in UCS compared to untreated samples, respectively.
Civil Infrastructure Researches
University of Qom
2783-140X
6
v.
2
no.
2021
67
78
https://cer.qom.ac.ir/article_1837_c03da3460458b67a24b9f5a6e49e4472.pdf
dx.doi.org/10.22091/cer.2021.6858.1241
Investigation Experimental Of the Concrete Properties Containing Bentonite and Zeolite as Natural Pozzolan
Sara
Khosravi
Faculty of civil engineering. semnan university. semnan. iran
author
Omid
Rezaifar
Associate Professor, Faculty of Civil Engineering, Semnan University, Semnan, Iran
author
Majid
Gholhaki
Faculty of Civil Engineering, Semnan University, Semnan, Iran.
author
Seyedeh Marzieh
Qiyami Taklymi
Faculty of Civil Engineering, Semnan University, Semnan, Iran
author
text
article
2021
per
Using pozzolanic materials in concrete manufacturing is intended as an optimal solution to lower the rate of greenhouse gas emission, and diminish energy resources and cement consumption. This research is aimed at evaluating Semnan zeolite and bentonite as partial replacement of cement in concrete. Twelve bentonite and zeolite mixes and control mix were examined. The main variable is the proportion of bentonite and zeolite (5, 10, 15 and 20%) by weight of cement in replacement mode while the amount of cementitious material, water to cementitious material ratio, fine aggregate content were kept constant. To study properties of hardened concrete, compressive strength and splitting tensile strength tests were performed. According to the results of compressive strength test, using bentonite and zeolite results in 5% increase in compressive strength as compared with the control mix (without bentonite and zeolite). By replacing 20% of zeolite with the weight of cement, the compressive strength is reduced by 9%. In most samples, Bentonite and zeolite as partial replacement of cement, it is possible to obtain the compressive strength acceptable. According to the results in mixtures containing zeolite and bentonite, if the amount of zeolite and bentonite are more than 10% by weight of cement, the tensile strength is reduced by 23% compared to control mix.
Civil Infrastructure Researches
University of Qom
2783-140X
6
v.
2
no.
2021
79
93
https://cer.qom.ac.ir/article_1852_f72216ef4dee46895df5cd4af236b38d.pdf
dx.doi.org/10.22091/cer.2021.6931.1248
Investigating the Factors Affecting Groundwater Level Decline in Kouhdasht Aquifer, Lorestan Province
Elham
Fijani
School of Geology, College of Science, University of Tehran
author
Saba
Alikhani Joudaki
School of Geology, College of Science, University of Tehran
author
Morteza
Mozafari
School of Geology, College of Sciences, University of Tehran, Tehran, Iran
author
text
article
2021
per
Quantitative management of groundwater resources is very important, especially in arid and semi-arid regions. Like other plains of Iran, Kouhdasht plain has been also facing a groundwater decline in recent years. This study is aimed to investigate the factors affecting groundwater decline in Kouhdasht aquifer. For this purpose, precipitation data from the Kouhdasht synoptic station, groundwater level data in observation wells and groundwater abstraction data in the study area have been applied. The representative hydrograph for a period of 29 years (1989-2018) showed that the aquifer water level decreased by 22.50 meters (average 77 cm per year) during this period. Groundwater decline maps also indicated that the groundwater level in the north and south of the plain has been decreased more than in the middle. According to the results, overexploitation from authorized and unauthorized abstraction wells, occurrence of drought (according to the calculated groundwater drought index), reduction of surface water resources and recharge from rainfall are the most important effective factors in the groundwater drawdown in Kouhdasht aquifer.
Civil Infrastructure Researches
University of Qom
2783-140X
6
v.
2
no.
2021
95
105
https://cer.qom.ac.ir/article_1876_f82d869792ac5e77e9830ee382329898.pdf
dx.doi.org/10.22091/cer.2021.6978.1253
Investigation of Discharge Coefficient of Triangular Duckbill Labyrinth Weirs Using Fluent Software and Gray Wolf and Elections Algorithms
Somayeh
Emami
Water Engineering Department of Tabriz
author
Javad
Parsa
Water Engineering Department, University of Tabriz
author
Hojjat
Emami
Assistant Professor of Computer Engineering, Faculty of Engineering, University of Bonab
author
Akram
Abbaspour
Associate Professor, Department of Water Engineering, University of Tabriz
author
text
article
2021
per
Labyrinth weirs are important hydraulic structures for water level regulation and flow control in canals, rivers, and reservoirs. Due to the uneven distribution of hydraulic head on the weir crest, the discharge coefficient changes along the labyrinth weirs are noticeable. For optimal use of this type of weir, it is necessary to estimate the discharge coefficient. In this regard, in this study, using a data set including 120 experimental data collected by Kumar et al. (2011) and numerical (simulated by FLUENT software using k-ε RNG turbulence model) to optimally estimate the discharge coefficient of triangular-duckbill labyrinth weir embedded in a rectangular channel 0.28 m wide, 12 m long and 0.41 m high was addressed using modern gray wolf meta-heuristic (GWO) and election (EA) algorithms. To investigate the effect of discharge coefficient, angles of 30, 60, 90, 120, 150 and 180 degrees with weir height of 10 cm were selected and the flow conditions in all cases were considered as subcritical, turbulent and falling flow. The objective function is the sum of the squares of the difference between the computational flow and the observations defined as the minimum. Comparison of the results of GWO and EA algorithms and FLUENT software with values of R2=0.96 and NRMSE=0.052 in comparison with the observed values, shows a good agreement between the observed and computational values.
Civil Infrastructure Researches
University of Qom
2783-140X
6
v.
2
no.
2021
107
121
https://cer.qom.ac.ir/article_1877_02e2c271af9298bedacbafa1872a4614.pdf
dx.doi.org/10.22091/cer.2021.6942.1250
Predicting the Behavior of Concrete Dams Using Artificial Neural Networks (Case study of Dez Dam)
Hosein
Naderpour
Faculty of Civil Engineering, Semnan University, Semnan, Iran
author
Seyed Rohollah
Hoseini Vaez
Department of Civil Engineering, University of Qom, Qom, Iram
author
Naser
Malekshahi
M.Sc. Faculty of Civil Engineering, Semnan University, Semnan, Iran
author
text
article
2021
per
Large dams store a significant amount of water behind them. Therefore, their safety and stability control have a special place. Changes in temperature and hydrostatic pressure are the most important factors that affect the dam structure; And will cause shifts in the crown of the dam upstream and downstream. Therefore, the data obtained from the monitoring center should be evaluated regularly in order to analyze the behavior of the dam. Due to this issue, in this study, using artificial neural networks, a model is presented to predict the horizontal displacement of the Dez dam crown due to changes in pressure and temperature. According to the results, it is observed that the neural network has a good performance in predicting real values. The average error of the modeled network is about 4%. This indicates that the network is well trained. Using the generated network, the radial displacement changes against the reservoir water level for different temperatures are obtained, and plotted. Using diagrams, it is possible to predict the behavior of Dez dam for different temperatures and changes in reservoir water level, which can be very useful in monitoring and maintaining this dam.
Civil Infrastructure Researches
University of Qom
2783-140X
6
v.
2
no.
2021
123
132
https://cer.qom.ac.ir/article_1878_4a6eb3052f059b3ba1d1d3564e5c74c3.pdf
dx.doi.org/10.22091/cer.2021.6898.1242
An Investigation on Irregular Steel Moment-Frame Structure Under Different Column Removal Scenarios
Masoud
Ahmadi
Department of Civil Engineering, Ayatollah Boroujerdi University, Boroujerd, Iran
author
Mehdi
Ebadi-Jamkhaneh
Department of Civil Engineering, School of Engineering, Damghan University.
author
text
article
2021
per
This research examines the effect of plan irregularities on the progressive collapse of steel structures. Firstly, the three structures, regular and irregular are designed. Secondly, the effect of the two plan irregularities on the progressive collapse of moment resisting frame assessed. The collapse patterns of the buildings are analyzed and compared under seven loading scenarios using non-linear dynamic and pushdown analyses. In the non-linear dynamic analyses, node displacements above the removed columns and the additional force on the columns adjacent to them are discussed. Furthermore, the strength and capacity of the columns are compared to determine their susceptibility to collapse. In the non-linear static analyses, the pushdown curve and yield load factor of the structures are obtained after column removal. The results indicate that an irregular structure collapses in most of the column removal scenarios. Moreover, when comparing regular and irregular structures, the demand force to capacity ratio (D/C) of the columns in the irregular structures is on average between 1.5 and 2 times that of the regular ones.
Civil Infrastructure Researches
University of Qom
2783-140X
6
v.
2
no.
2021
133
147
https://cer.qom.ac.ir/article_1859_2e13f1a7167019bdfb13e171d40b4b6c.pdf
dx.doi.org/10.22091/cer.2021.6905.1244
Proposing Regression Models to Estimate Uniaxial Compressive Strength and Elastic Modulus of the Sandstones Based on Physical Properties and Compressional Wave Velocity
Amir
Azadmehr
Department of Mining Engineering, Birjand University of Technology, Birjand, Iran.
author
Mohsen
Saffarian
Department of Industrial Engineering, Birjand University of Technology, Birjand, Iran.
author
Sayed Mahmood
Kazemi
Department of Industrial Engineering, Birjand University of Technology, Birjand, Iran.
author
text
article
2021
per
Many engineering structures have been built on the sandstones. The main purpose of this study is to estimate the uniaxial compressive strength (UCS) and modulus of elasticity (Es) of sandstones using regression models. For this purpose, petrographic studies, compressional wave velocity (Vp), porosity, density and uniaxial compressive strength tests were performed on dry and saturated samples of sandstones prepared from Mosha village in the northwest of Damavand city. The studied sandstones were classified as feldspathic litharenite and litharenite. Due to the effect of moisture on the physical and mechanical properties of these sandstones, the density and Vp of the samples in the saturated state compared to the dry state have increased by 4 and 20%, respectively. In contrast, UCS and Es have increased by 18% and 25%, respectively. The results of simple regression showed that the most accurate relationship (the highest correlation coefficient and the lowest error) of porosity, Vp and density with UCS and Es are logarithmic, linear and quadratic polynomials, respectively. Based on the determination coefficient (R2=0.5-0.77) and the errors (RMSE=10.29-18.26; MAPE=1.70-2.80), the relationships presented by simple regression method for estimating UCS and Es showed high accuracy. The Vp and porosity also have the greatest impact on UCS and Es. Evaluation of empirical relationships of other researchers showed that some of these relationships have a determination coefficient of more than 50%. Examination of residual variance homogeneity graphs at the predicted value levels, determination coefficient and error of the methods showed that multivariate regression (R2=0.73-0.74, RMSE=13.36-13.56, MAPE=1.06-1.22, Durbin-Watson= 1.56-1.70) has a high accuracy for estimating UCS and Es as compared to the simple regression.
Civil Infrastructure Researches
University of Qom
2783-140X
6
v.
2
no.
2021
149
170
https://cer.qom.ac.ir/article_1888_ed99ed02ebb6a03a666e8f5b8d9fb6c7.pdf
dx.doi.org/10.22091/cer.2021.6923.1247