Reza Ziaee Moaed, ,
Volume 4, Issue 1 (11-2010)
Abstract
Saline soils are of challengeable soils that may cause many problems in civil engineering projects. In this study, volume change behaviour of saline soils and also the effect of improvement and reinforcement on them have been investigated using laboratory tests as well as consolidation test, swelling pressure test and free swelling test. The case study is Amirkabir Highway which connects the cities Qom and Kashan. Fifty four kilometer of this highway was deformed like waves due to existence of saline soils. The laboratory investigations showed that the studied soil has a considerable swelling potential which appears to be the main cause of damage to the highway pavement, therefore it is decided on improving the subsoil condition. The research program comprises of studying volume change behavior of saline soil, stabilized with lime and epoxy – resin polymer and reinforced with polypropylene fiber. Afterwards, results for two cases of stabilized and non-stabilized samples have been compared. According to the results, the main cause of swelling is soil disturbance and structure destruction of initial soil composition. Considering all of test conditions, it is appeared that, although lime is a traditional stabilization material but is economic for the most geotechnical projects and usage of polymer is suggested only in special applications due to its rapid setting
Mahdi Jalili Ghazizade, Mohammad Ali Abduli, Edwin Safari, Behrouz Gatmiri,
Volume 5, Issue 1 (9-2011)
Abstract
Desiccation cracking commonly occurring in compacted clayey soils typically used as landfill liners can result in poor hydraulic performance of the liner. In this research, a simplified image processing technique was developed in order to characterize desiccation cracking intensity in compacted clayey soils. Three pairs of compacted clayey soils were studied in a relatively large scale experiment to evaluate the effect of geotextile cover on desiccation cracking under real-time atmospheric conditions. Digital images were taken from the surface of soils at certain time intervals for 10 months and were analyzed to determine crack intensity factor (CIF). The key parameter in identification of cracks as accurately as possible was found to be sensitivity. Calibration process was based on using %20 of the images with different crack intensities whose crack dimensions and therefore CIF values have been already measured to compare to program output. A calibration coefficient for sensitivity was accordingly determined based on the average difference between the sensitivity introduced by the program and the actual sensitivity calculated based on an overlaying process. Result of verification of this methodology indicated that it can be reliably used to determine CIF of compacted clay soils in a simple yet accurate manner.
Salman Soori, , , ,
Volume 5, Issue 2 (4-2012)
Abstract
The Keshvari watershed is located at south east of Khorramabad city in Lorestan province. This area is one part of the folded Zagros zone based on structural geology classification. By consider the type of geological formations, topographic conditions and its area, this watershed is very unstable and capable for occurring landslide. In this study, artificial neural network (ANN) with structure of multi-layer percepteron and Back Propagation learning algorithm used for zonation of landslide risk. The results of ANN showed the final structure of 9-11-1 for zonation of landslide risk in Keshvari watershed. According this zonation, 23.81, 7.53, 6.49, 18.68 and 43.47 percent of area are located in very low, low, moderate, high and very high risk classes, respectively.
, Greza Khanlari, M Heidari, Yazdan Mohebi, Reza Babazadeh,
Volume 7, Issue 2 (3-2014)
Abstract
Awareness of orphological features of rivers is necessary for recognition of river behavior and optimum application of rivers. Overall catchment physiografy have important role for determination factors such as floods, erodible and sediment mutagenicity. In this study in order to understand the behavior of Gamasiab River in the east of Kermanshah province, geomorphologic features of this river has been considered. Study of engineering geomorphologic properties is done by using existing data from previous studies, site visit and field perceptions, study of geology and topography maps. Physiographic properties of catchment, channels morphologic properties and geology conditions in this region have been studied. In this research, several parameters such as average width, environment, area, hydrogeologic coefficient, catchment form, maximum, minimum and mean high, and longitudinal slope has calculated. Also status of drainage density of this river has been investigated and time to focus calculated. Finally this river review and classified according to various classifications for rivers
Majid Dashti Barmaki, Mohsen Rezaei, Amir Saberi Nasr,
Volume 8, Issue 2 (11-2014)
Abstract
This paper has evaluated the groundwater quality index of Lenjanat aquifer. Water quality index as a unique index is presented to describe overall water quality conditions using multiple water quality variables. Physical and chemical data of 66 water samples were used in this study. The results have been obtained by Comparing the qualitative features with the World Health Organization (WHO) standard and Industrial Research of Iran (ISIRI) standards. In calculating GQI, 7 parameters, including calcium (Ca), magnesium (Mg), sodium (Na), chlorine (Cl), sulfate (SO4), total dissolved solids (TDS) and nitrate (NO3) have been used. Groundwater quality index shows the medium to relatively high groundwater quality in the study area. Minimum and maximum value of the index is calculated as respectively 55 and 93. Land use map shows that along the Zayanderood River and around the location of rice paddies, water quality reaches to the lowest quantity. Optimum index factor technique allows the selection of the best combination of parameters dictating the variability of groundwater quality.
N Shariatmadari, M.mehdi Yazdanpanah, Saeid Saeidijam,
Volume 8, Issue 3 (12-2014)
Abstract
Saline sea water, groundwater into salt domes or municipal waste leachate can affect hydro-mechanical properties of bentonite as a sealing material in nuclear waste repositories or landfills. This paper investigated the effect of sodium chloride solution on Atterberg’s limit, swelling, consolidation and permeability of bentonite. Swelling and consolidation test had been done at 0.05, 0.1, 0.5 and 2 molar solution and pure water by oedometer apparatus in Iran University of Science and Technology. Considering the results, it can be seen that a little increase in concentration of the solution reduces swelling of bentonite. So that the swelling potential of bentonite reduced from about 82% to about 1.5% by increasing in concentration of the solution from pure water to 2 molar solution. Liquid limit and plastic index of bentonite were reduced by increasing concentration of the solution but plastic limit was not changed significantly. Meanwhile increased concentration of the solution will facilitate reaching equilibrium for swelling and consolidation of the samples which occur due to their enhanced permeability. Permeability of bentonite increased about 7 times by increasing in concentration of solution from pure water to 2 molar solutions. Also, the Compressibility of bentonite was reduced by increasing in concentration of sodium chloride in the solution.
Vr Ohadi, M Amiri, Mh Ohadi,
Volume 9, Issue 1 (6-2015)
Abstract
The main objective of this research is to investigate the mechanism of cement-clay-heavy metal contaminant interaction from micro-structural point of view. To achieve this objective series of batch equilibrium and XRD experiments were performed. The results indicate that the addition of 10% cement not only stabilizes the soil, but also at 250 cmol/kg-soil of heavy metals causes 130% increase in heavy metal retention. Furthermore, the XRD analysis shows that in solidified samples with less than 10% cement, the main reason for reduction in peak intensity of clay fraction is due to the presence of heavy metals. However, as the percentage of cement increases, the clay solubility is the main reason for reduction in peak intensity of montmorillonite in XRD test
T Nasrabadi,
Volume 9, Issue 2 (9-2015)
Abstract
In contrast with Mobility Factor (MF) and Risk Assessment Code (RAC) indices, IR attributes a risk share to metal species bound to reducible and oxidizable phases which are totally neglected in both of the two above-mentioned indices. In other words, besides the absolutely mobile fractions, the potentially mobile ones are also regarded in risk evaluation process elaborated by IR. The different structure of the newly-developed index may prevent risk level underestimation especially in case where a remarkable percent of bulk concentration is accumulated within reducible and oxidizable phases. The independency of the index value to the bulk concentration makes it possible to discuss the potential risk in different levels of bulk concentration. Furthermore, the index capability in indication of risky pollution, regardless of the pollution source type, may prevent the probable misleading caused by distinct separation of bulk concentration into geopogenic and anthropogenic portion
Davood Fereidooni, Mohammad Hossein Ghobadi,
Volume 9, Issue 2 (9-2015)
Abstract
In order to assess mineralogical composition influence on durability and strength of rocks, four samples of hornfelsic rocks were selected from southern and western parts of the city of Hamedan, west of Iran. These rock samples were subjected to mineralogical, physical and mechanical tests in the laboratory. Also, they were evaluated in 15 cycles of slake-durability testing in different pH of sulfuric acid solutions and XRD analysis. Based on the results, the type and amount of minerals, their density and hardness had an influence on the uniaxial compressive strength and the slake durability index of tested rocks. That means, presence of non-dissolved minerals such as graphite in studied rocks, decreases Unconfined Compressing Strength (UCS) but increases the slake durability index. The results of slake-durability test indicated that weight loss of the samples at initial cycles was found to be higher than the end cycles. Also, in these samples, initial minerals in the fresh samples were not exchanged by secondary minerals such as clay minerals. Therefore Hamedan hornfelsic rocks are approximately resistant when were put under accelerated chemical weathering and degradation in the laboratory and natural chemical weathering.
Salman Soori, Siamak Baharvand,
Volume 9, Issue 4 (3-2016)
Abstract
Landslide is one of the mass movement processes that occur in Iran and parts of the world every year. It causes huge human loss and economical damages. In order to check the stability of slopes in Kakasheraf basin, in the first step sliding areas were identified using the aerial photography and field surveys and then distribution map of landslide is provided. The impact of each of these factors which included dip, aspect, altitude, lithology, landuse and distance from the road and drainage are assessed through Arc GIS software merging the effective factors on landslide with the landslide distribution map. Then these factors were prioritized using AHP model. In this study, the fuzzy logic and density area method has been used in the Kakasheraf basin in order to identify landslide hazard zonation. The empirical probability index (EPI) has been used to assess and classify the models outputs in the landslide risk estimation.Results show that the fuzzy logic is more applicable method than density area model for mapping the landslide risk in Kakasheraf basin
Sahar Rezaian, Seyed Ali Jozi, Sadaf Ataee,
Volume 10, Issue 2 (11-2016)
Abstract
Objective of the present research is to identify, analyze, and assess risk of Paveroud Dam during construction phase. Following collection and analysis of the information related to environmental conditions of the area of study and technical specifications of dam construction, a list of probable risk factors was prepared in the form of a questionnaire, and for verification, the questionnaires were provided to a group of specialists consisting of elites and professors specialized at the disciplines relevant to environment and civil engineering. Number of questionnaires was determined based on Cochran’s formula. In the first step, the expert group in the research was asked to score in Likert scale format so as to analyze the acquired responses and the risks present in the region. Having analyzed the scores using the findings of PHA method, TOPSIS technique was applied to prioritize the identified risks of Paveroud Dam. The results indicated that erosion had the highest priority among 36 risk factors. After prioritization among the risk factors, risk was also assessed using RAM-D technique in which “impact on Sorkhabad Protected Zone with 9 scores, “erosion” with 6 scores, and “work at high elevation” with 3 scores were recognized as three major risks of Paveroud Dam. In order to mitigate the effects of dam risks during construction phase, environmental management planning is crucial, and for this purpose, risk mitigation choices were recommended at the end aimed at coping with the identified risks.
Azam Masoodi, Mohammad Reza Majdzadeh Tabatabi, Ali Noorzad,
Volume 10, Issue 2 (11-2016)
Abstract
Subsurface flow contributes considerably to river flow and plays an important role in river sediment loads. This research has been focused on investigation of soil properties and bankstream slope on seepage erosion. For this purpose a series of lysimeter experiments were performed for four different slopes of bankstream by varying the soil grain sizes. The obtained results indicate that Reynolds number in porous medium plays an effective role in depth of scour hole in noncohesive layer. It was observed that the time of beginning of sediment motion decreases with an increase in the soil grain size.
Mahsa Rokhbar, A Qishlaqh, G Forghani,
Volume 11, Issue 4 (5-2018)
Abstract
Introduction
Exploitation or processing of ores is usually associated with the production of a large amount of waste materials. These materials often have a high concentration of metals which can enter the environment through weathering or erosion. It is well-known that the measurement of the total concentration of metals cannot be an adequate for evaluating the pollution status of soil. Therefore, in most studies on soil contamination, bioavailability content of metals is determined by which can predicate the fate of the metals entering into the other parts of the environment such as plants, water or human food chain. The bioavailability of metals in the soil environment is the exchangeable and absorbable metals for plants, which depends on their exchangeability and absorption by soil organisms especially plants. This is also the function of the chemical form of each element in the soil. The main purpose of the present study was to measure the total concentrations along with the bioavailable content of metals in soils and plants around the Irankuh mine tailing dams.
Area of study
The Irankuh lead and zinc mine is located 20 kilometers southwest of Isfahan. This mine is of MVT type Pb-Zn deposit which occurred mainly in limestone and dolostone of lower cretaceous age. The Irankuh mine is an open-pit mine with annual extraction of 358 thousand of PbO and ZnO. The exploitation of mine is also associated with the production of a large amount of waste material which is piled in open dumps around the mine. The main minerals of ores are galena, sphalerite and pyrite.
Materials and methods
31 sampling sites were selected randomly for collecting agricultural soils around the tailing dams. Each soil sample is actually composite sample of four samples which are taken from a depth of 15 to 20 cm. Seven cultivated plants (
Ocimum basilicum) were sampled from green houses in the vicinity of tailing dams. After drying and sieving, about 50g of the soils are chemically analyzed in order to determine the total concentration of the metals by the ICP-OES method. Plant samples after drying were changed to ash in the furnace at temperature > 500 C. The concentrations of metals (Zn, Pb and Cd) were then measured by Atomic Absorption Spectrometers in their stem, roots and leaves.
pH samples of soil were also determined using the EPA 9045 method. Walkley and Black method were used to measure the amount of organic matter. The cation exchange capacity (CEC) of soil samples was also determined based on EPA 9087 method. Soil texture determined using hydrometric method and then classified according to USDA classification. Diethylene Triamine Pentaacetic Acid (DTPA) extractable metals (bioavailable content) were determined using the method by Lindsay and Norvell (1978) and their concentrations in the DTPA extracts were determined by Atomic Absorption Spectrophotometer (AAS).
The metal transfer from soil to plant was calculated using the transfer factor (TF: metal content in plant divided by metal content in soil).
Results and discussion
The soil pH of the studied samples varies from 7.36 to 8.35. Cation exchange capacity (CEC) of soil samples was estimated to be in the range of 4 to 22.2 Meq/100 g. Also, the amount of organic matter in the studied soil samples varies from 0.17 to 3.43%. The relative high levels of soil organic matter are probably due to addition of organic manure to soil through agricultural activity. The total concentration of these three matls are significantly higher than their corresponding values in the crust implying that the mining activity and tailing dams greatly elevated the concentration of these metals in soils. Statistically, there is a significant positive correlation among Zn, Pb and Cd (at confidence level of 0.01) indicating that their potential source is the same or having similar geochemical behavior in the soil. The soil clay content showed a significant correlation at the level of 0.05 with Zn, Cd and Pb. This indicates that clay fraction plays a significant role in absorption of these metals in soil. According to the results of single extraction (DTPA method), the proportion of available content for Cd is higher than that of Zn and Pb. Cadmium is often characterized by its high mobility in soil media. Based on the correlation coefficients at the confidence level of 0.01, it is also observed that the increase in total concentration of Cd increased its bioavailability content in the soil consequently increase the availability of other elements in the soil. Therefore, it can be inferred that the availability of Cd in the soils of the study area is likely to be increased in the presence of Zn and Pb because in sites where the total concentration of Pb and Zn is high, the content of Cd availability has also elevated.
Based on the comparison of the average concentration of the metals in different parts of the plants, the concentration of metals is ordered as follows stem> leaf> root, which indicates the high root capacity for the accumulation of metals. The average transfer factor (TF) for Cd is obtained much higher than those of Zn and Pb. There is also a negative significantly correlation between the concentrations of Cd in the aerial parts of the plants and its bioavailability concentration in the soil. Also, there is positive and significant correlation between Zn and Cd for all three different parts and its bioavailability concentration in the soil. In the case of Pb, a significant correlation is observed between stem and root parts. This means that Cd and Zn after being absorbed by the root, are more likely being uptake by the plants due to high mobility of zinc. However due to less mobility of Pb, it is seemingly entered into the plant aerial parts after absorption by the root.
Conclusion
The concentration and degree of contamination of the studied soils is very high in terms of total Pb, Zn and Cd concentrations in agricultural soils around the Irankuh mine. The increased heavy metal contents in soils can be attributed to mining activity and tailing dams near cultivated lands
. The measurement of the bioavailable content of these metals indicates that the Cd has the highest availability as compared to Zn and Pb. The average concentration of Pb and Cd in different parts of plant which is higher than the permissible limits, implying that the transfer of the available metal part (especially Cd) from the contaminated soil into the plant. Based on the calculated health risk assessment index in this study, it can generally be concluded that the gradual accumulation of these metals, especially in aerial parts of basil might have health hazards for local consumers.
./files/site1/files/0Extended_Abstract3.pdf
Alireza Rastikerdar,
Volume 14, Issue 2 (8-2020)
Abstract
Introduction
Solid waste is one of the unavoidable products of every society that necessitates the establishment of municipal solid waste management system. Because of variability in quantity and composition of municipal solid wastes, several management scenarios are considered. Assessing the environmental impacts of the life cycle of these scenarios will have a significant role in reducing and resolving urban service management problems. The aim of this study was to compare different scenarios of municipal solid
waste management in Sirjan city using life cycle assessment (LCA) approach. LCA methodology is used to evaluate the environmental performance of the waste management of Sirjan for different scenarios, according to the ISO standards 14040 series 2006.
Material and methods
After identifying the quantitative and qualitative characteristics of the produced wastes within the scope of the study, the quadratic steps of the LCA method are followed in relation to each of the scenarios. The stages of life cycle assessment in the present research are as follows:
1. Determining goals and scope: Our goal is to compare environmental impacts of scenarios that include different methods of disposal. The boundaries of the study start from the collection of municipal solid wastes from the transfer station and end
s with the final disposal of waste (Figure 1)