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H. Taherkhani, M. Javanmard,
Volume 9, Issue 4 (3-2016)
Abstract

One of the major problems associated with the clayey soils is the swelling potential due to moisture absorption, which results in applying high pressure on the superstructures, and may cause failure or large deformation of the structures. Among the solutions to mitigate the swelling problem of clayey soils is their stabilization using additives. This study aims to compare the effects of three types of additives on the reduction of swelling potential of two types of clayey soils, with two different plasticity indexes. The additives used in this research include two traditional additives namely, cement and lime, and one type of nontraditional stabilizer namely, CBR PLUS nano polymer. These additives were added to the soils in different contents, and the Atterburg limits, and the swelling of the soils were measured at different times after addition of the additives. The results show that the CBR PLUS is more effective in reducing the swelling potential of the soil with high plasticity index, by which, the swelling was reduced by 1500%, while the addition of  lime and cement reduced the swelling about 1000%. For the soil with low plasticity index, the cement is found to be more effective than the lime and CBR PLUS in reducing the swelling potential. The addition of 7% of cement resulted in 1400% of reduction in swelling, against 600% reduction for the addition of the same content of lime. In addition, it is found that the CBR PLUS and cement are, respectively, more effective in reducing the plasticity index of the soil with high and low plasticity index
V Shirgir , A Mohammad Amiri , A Ghanbari , M Derakhshandi ,
Volume 10, Issue 4 (Vol. 10, No. 4 Winter 2017 2017)
Abstract

Free vibration of soil often occurs during earthquakes. Since the vibration caused by earthquake does not have (steady state harmonic vibration) continuity, the alluvium vibrates with its natural frequency between two natural seismic waves. This study evaluates the effect of piles on the period of free vibration of a soil layer using numerical method. In the first stage, using analytical equations for calculation of vibration period of a soil layer and a column with continuous mass, the results were analyzed by the software. In the second step, piles with the same dimensions and distance were added step by step, and the vibration period for the soil layer with piles was calculated. The friction or floating effects of the piles on alluvial soil vibration period was also examined. The results show that as the number of piles increases, the differences between the results of one dimensional analysis of alluvium soil and the results of the software become different, and this creates the need for specific arrangements for seismic analysis of this kind of alluvium (with inserted piles). The results also suggest that end-bearing piles have a greater effect on alluvial soil vibration period, and with increased amount of the floating of these piles, these effects decline.


 


H Hataminia , M Khanmohammadi , A Ghalandarzadeh ,
Volume 10, Issue 5 (2nd conferences on earthquake engineering (Alborz Province) 2016)
Abstract

Tanks are structures for storing fluids that are made in different sizes, shapes and genera. Today using of tanks for water, petroleum products storage, and industrial wastes, has been developed significantly. The buried rectangular concrete tanks are used for water supply in most cities in our country. Soil-structure interaction is one of the most important issues in seismic behavior of buried tanks. With respects to code 123 that has suggested Mononobe-Okabe equation for dynamic pressure of earthquake excitation, the purpose of this research is to achieve the dynamic pressure of soil during earthquake. The obtained results have been compared to analytical and other experimental researches. Therefore, a series of small-scale experimental tests were conducted using 1g shaking table testing in the laboratory of physical modeling at University of Tehran. The results illustrate that dynamic force and pressure from Mononobe-Okabe and Wood equation are greater than experimental testing results. However Seed-Whitman equation is closer to experimental results.


Aliakbar Momeni, Gholamreza Khanlari, Mojtaba Heidari, Yasin Abdilor,
Volume 11, Issue 1 (Vol. 11, No. 1 Spring 2017 2017)
Abstract

./files/site1/files/7Extended_Abstract.pdfExtended Abstract
 (Paper pages 135-156)
Introduction
Many civil structures (e.g. tunnel walls, bridge pillars, dam abutments and road foundations) are subjected to both static and dynamic loads. Cyclic loading leads to occurring fatigue phenomenon. Fatigue is the tendency of materials to break, or the process of damage accumulation, under cyclic loading. It was found that the dynamic fatigue strength can be reduced by 30-70 percent on average compared to uniaxial compression strength. Different materials show different response when they are subjected to cyclic loading. Some materials become stronger and more ductile, while others become weaker and more brittle. Although it is clear that the mechanical properties of rock under dynamic loads varied dramatically from those under static loads, the nature of dynamic failure in rock remains unclear, especially in cyclic loading condition. Fatigue behavior of rocks was rarely studied in respect to other materials such as steel and soil. The performed researches on fatigue behavior of rocks indicated that fatigue life will be decreased by increasing load amplitude in logarithmic and exponentially pattern. Also, strain softening is the dominated behavior of rocks against cyclic loading. Furthermore, some parameters such as maximum load level, confining pressures, amplitude, and loading frequency have considerable effects on fatigue behavior of rocks. However, available data on fatigue behavior remain insufficient for solving the practical tasks of predicting rock bursts and earthquakes. Obtained results are inconclusive and sometimes discordant. The aim of the current work was to assess tonalite rock fatigue behaviour under different loading conditions to describe the fatigue damage process of the granitic rock.
Material and methods
Several core samples were prepared to perform this research. The core samples were prepared with a L/D ratio of 2.5 with an average diameter of 54 mm. Before the fatigue tests, the physical and mechanical properties of the rocks were measured. Uniaxial compressive strength test (UCS) has been done on 5 core samples. The tests were performed in the load-control mode with a 1.6 kN/s loading rate. The tests were conducted to obtain the physico-mechanical parameters of the rocks in static loading condition, and provided a reference for subsequent dynamic tests. The cyclic tests were performed in both load and displacement control modes. To record axial and lateral strains during the fatigue tests, four strain gauges have been employed with arrangement of two axial and two laterals. Also, three acoustic emission sensors were installed on top, mean and bottom of the core samples to record cracking sound. In order to doing the tests a servocontrol Instron machine with 500 kN capacity was employed. The fatigue tests were conducted with three different maximum loads, 1 Hz frequency, and constant amplitude (0.82 of uniaxial compressive strength). The maximum stress level (the ratio of maximum cyclic stress to static strength) was varied 0.80, 0.85, and 0.90. The amplitude level (the ratio of amplitude stress to static strength) ranged from 0.50 to 0.70 and 0.90. Finally, Multi stages loading with increasing amplitude were applied for the displacement control tests. The results of fatigue tests have been evaluated by fatigue damage parameters including maximum and minimum axial strain, maximum and minimum lateral strain, tangent and secant modulus, toughness and hysteresis energy.
Results and discussion
The obtained results indicated that during fatigue process failure occurs below the maximum strength loading condition as a result of accumulative damage. Analysis of the fatigue test results showed that the fatigue failure consisted of three stages: fatigue crack formation (initiation phase I), stable crack propagation (uniform velocity phase II), and unstable crack propagation resulting in a sudden breakdown (accelerated phase III). By comparing the axial and lateral deformation, it was found that lateral deformation is more sensitive to fatigue. At higher stress levels, considerable part of fatigue life is response to crake development, whereas at lower stress levels, crack acceleration phase of fatigue life is distinguishable. Descending trend of loading and unloading tangent modulus shows a scatter pattern. This behavior may be related to the calculation method and loading condition, as well as microstructure and behavior of the rock mass. In spite of tangent modulus results, the three-stages of damage process (especially phase I and II) for secant modulus in both loading and unloading conditions are clear. The result is due to the method of calculation and increase in axial strain with increasing number of cycles. Brittle behavior of this type of rock leads acceleration phase to be hidden and unclear in most of fatigue damage parameters. A dramatic decrease of toughness and hysteresis energy in the first few cycles is due to the closing of pre-existing micro fractures. In fact, during the initial cycle, the rock behaves in a more ductile fashion than in the next few cycles. Thereafter, toughness begins to increase slowly, then steadily, and finally rapidly. A similar behavior was found for hysteresis energy as well. This fact indicated that cracks generated in parallel to loading direction. Fatigue displacement control tests show a strain softening behavior for the granitic rocks. This behavior is highlighted in variation of maximum stress during the tests. This parameter, especially in final step of loading, shows distinguishable decreasing trend.
Conclusion
The tonalite rocks were subjected to uniaxial cyclic loading in both load and displacement control mode. The following conclusions were drawn from this research.
-Accumulated fatigue damage occurs in an obvious three-stage process. This is the result of the micro-fracturing mechanism in the fatigue process.
-By comparing axial and lateral strain damages, it was found that crack propagation occurred in the loading direction and crack opening occurred in the lateral direction. So, among fatigue damage parameters, lateral strain shows the best three-stage fatigue damage behavior.
- Strain softening was found as rock response to cyclic displacement control loading.
Khosrow Mehrshahi, Hamid Alielahi,
Volume 11, Issue 2 (Vol. 11, No. 2 Summer 2017 2017)
Abstract

./files/site1/files/5.pdfExtended Abstract
(Paper pages 247-276)
Intro
Behrouz Ahmadpour, Masoud Amel Sakhi,
Volume 11, Issue 3 (Vol. 11 No. 3 Autumn 2017 2018)
Abstract

Earth-fill dams stability in steady state seepage condition is very important, especially during earthquakes. Numerical software analyses require accurate and realistic modeling of construction stages. Since earth-fill dams are constructed in different layers, so these conditions should be considered in software modeling to achieve a reasonable design. In this study, an earth-fill dam is modeled in PLAXIS software and the effects of the number and shape of layers are studied in dry and steady-state conditions. Obtained results in static and pseudo-static analyses show that modeling of earth-fill dams with different layers has significant effects on shear stresses and horizontal displacements. For example, horizontal displacements and shear stresses, increase at least 50% and 17% respectively, in comparison with single layer models. According to the obtained results, it can be mentioned that modeling of an earth-fill dam in the layered model and rather in inclined layers are more reasonable
Sm Fatemiaghda, H Shahnazari, H Karami, M Talkhablou,
Volume 11, Issue 4 (Vol. 11, No. 4 Winter 1018 2018)
Abstract

Carbonate soils are different from silicate soils respect to their origination and engineering behavior. Particles of these soils are mainly residual or debris of sea animals or plants with large amount of calcium carbonate. They also may be chemical sedimentation of calcium carbonate over other soil particles in specific region of seas and oceans. The most important characteristic of these soils is the crushability of their aggregates under loading which is mainly due their shape and also small voids inside of them.  Crushability and subsequent volume changes in carbonate soils have caused many engineering problems in some geotechnical structures such as ...../files/site1/files/0Extended_Abstract5.pdf
Mahsa Rokhbar, A Qishlaqh, G Forghani,
Volume 11, Issue 4 (Vol. 11, No. 4 Winter 1018 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
Javad Khalaji Pirbalouti, Naser Hafazi Moghadas, Gholam Reza Lashkaripour,
Volume 12, Issue 3 (Vol. 12, No. 3, Autumn 2018)
Abstract

Introduction
Hazardous waste (solid, liquid or contained gases) is a waste with properties that make it potentially dangerous or harmful to human health or the environment. Site selection and suitable conditions for hazardous wastes landfill is considered as the final stage of waste management that they have high sensivity. The purpose of this study is to identify prone areas to hazardous waste landfill for Chaharmahal and Bakhtiari province using geographic information systems (GIS) as an important tool for the analysis of potential sites and the Analytical Hierarchy Process (AHP) and to provide solutions to optimize the positioning is executed. Firstly, criteria and limitations of environmental, economic, social and physical were determined, then layers of the criteria in GIS were prepared. In this study, the inappropriate areas were first removed from the model, and the suitability of remaining regions as a categorize criterion considered. Categorize criteria for paired comparison using AHP as an efficient tool for determining the relative weight parameters are used to measure and rank the expert choice application imposed. Then the implement paired comparison of the relative weights of the criteria and sub-criteria and criteria for each category were determined. After calculating the net weight and normal weight, normal weight based on standard maps in the GIS environment has been classifieds. Finally, by combining maps and applying criteria FA map, the final map was extracted.
Material and methods
The purpose of this research is to identify and prioritize appropriate areas of special waste disposal using multi-criteria decision-making methods. In order to locate using the GIS, first, identifying, evaluating and selecting criteria and constraints for the construction of landfill, in order to reduce the economic, environmental, and health costs. In the multi-criteria evaluation method, criteria are the basis of decision making, so that a set of criteria is combined and combined to achieve a single combination. In this paper, a two-stage process was used to locate the landfill site. In the first stage, which is recognized as the identification stage of prohibited areas according to different criteria, the study area is divided into two appropriate and inappropriate classes that will be eliminated as prohibited areas for the construction of landfills. In the second stage, the various factors are ranked and weighted according to the relative importance and, finally, places that receive the appropriate points are introduced as areas susceptible to the dumping of special wastes. In order to obtain the digital data of the criteria in the GIS environment from the digital elevation map (DEM), the specifications of the piezometric wells information are available from the regional water organization of the province. The available data such as geological map of the province at a scale of 1: 250,000, satellite images of Landsat and map of land suitability of the province, rainfall data of the synoptic stations of the province and the data of the Environmental Protection Agency were used. In general, the following steps have been taken in the process of locating:
- Identification of effective locating factors (limitations and factors)
- Digitizing and providing the required layers of information using the GIS package
- Identify and eliminate prohibited and inappropriate areas for landfill construction
- Classification and weighting of the factors and layers of information sought
- Integration of layers and the provision of a mapped rate and talent to determine the appropriate areas.
Results and discussion
1. Set limits
In this study, in order to select suitable sites for landfill particular, the criteria and limitations were determined. The information layers for each of the criteria were provided in the GIS environment.
2. Classification and weighting criteria
In the second stage, which is the stage of weighting and rating, of 14 effective criteria were used in site selection. AHP is one of the most efficient techniques, multi-criteria decision. This method is based on comparing factors and to study various scenarios to give managers and decision makers. This technique is one of the most comprehensive system designed for decision-making with multiple criteria.
3. Editor hierarchy to locate
Hierarchical structure is a graphical representation of a real complex problem, which mainly target the problem and at the next general criteria, sub-criteria and options are the way in AHP is used to calculate points based on comparison test.
4. Shipping Weight Matrix Binary comparison and decision-making
After compiling a hierarchical structure, the next step is to evaluate the elements by comparing the test. In general, if the number of options and criteria respectively m and n are then paired comparison matrix of options for comparison matrix m × m and n × n matrix will be a couple of criteria.
5. After weighing and preparing the normal weight of the options, the normalized weights in the GIS environment were added to the criteria map and the Raster and Weighted layers of each criterion were prepared. Due to the wide area of the studied area, the size of each pixel was 50 * 50 m. Then, using the Raster Module, the Criterion Map was combined and a zoning map was prepared for the special waste disposal site.
Conclusions
In the present study, according to various criteria influencing the Hierarchical Analysis Process for prioritizing the criteria in decision making, based on the results, the talent map of the area was prepared for special waste dumping, in which according to the final score of the layers, the area was classified into four appropriate, relatively suitable, relatively inappropriate and inappropriate classes. Suitable areas were 12.64%, relatively fairly 32.47%, relatively inappropriate 30.43%, and inappropriate zones 9.58% of the area of the talent map were included.
./files/site1/files/123/5Extended_Abstract.pdf
Ali M. Rajabi, Hossein Khosravi,
Volume 12, Issue 4 (Vol. 12, No. 4 2018)
Abstract

Introduction
In general, landslides, in particular, earthquake-induced landslides, are among the phenomena that have caused great damages in recent years in Iran and the world. Although many studies have been done on the identification and description of landslides in general, the study of landslides caused by the earthquake, especially in Iran, is at the beginning stages. In a few studies, some landslides and some of their characteristics have been introduced. A magnitude 7.7 earthquake occurred in the Guilan Province was occurred on May 31, 1990. This earthquake is one of the most important earthquakes in Iran history due to its magnitude and occurrence of landslides. In various studies, the most important landslides have been listed. The development of quantitative and qualitative studies on earthquakes that have caused many landslides (such as the Manjil, Avaj, Firoozabad, Kojur, Sarein and Ahar and Varzaghan earthquakes) increase our understanding of natural disasters and, consequently, the management of the dangers resulting from them. The purpose of this research is to identify the factors affecting the occurrence of landslides caused by earthquakes, to determine the impact of each on the occurrence of this phenomenon, and also to prepare a map of earthquake hazard zonation hazard by utilizing the methods used in this research. In this study, hierarchical analysis method has been used to prioritize the factors affecting the occurrence of landslide and also the zoning of earthquake landslide hazard in the study area.
Research Methodology
The study area is located between 49˚ 30 and 4945˚ and latitudes 36º 0045" and 36º 30 52" with a surface area of ​​309.30 km2. In this research, in order to zoning the earthquake-induced landslides hazard, in addition to providing a map of landslides, seven factors influencing the occurrence of this phenomenon were identified and examined. These factors included elevation, slope, arias intensity, friction angle, adhesion, curvature of the slope and aspect. In this research, Analytic Hierarchy Process (AHP) method, one of the multi-criteria decision making models, was used with two approaches to using expert knowledge and data and expert knowledge together to prioritize the factors influencing the occurrence of landslide. Finally, two landslide hazard zonation maps were prepared. In a hierarchical analysis method related to the expert judgment, it was used to determine the priority of different criteria and sub-criteria and convert them into small amounts of oral judgments (expert opinion) based on the pair comparison, in which the decision maker preferred the factor in relation to other factors using the relevant tables, these judgments are converted into small amounts. In the method of using data and expert judgment simultaneously, first, in order to determine the priority of criteria from oral judgments (collection of expert opinions), we used to determine the importance or weight (Wi) of each sub-criterion (R) is also used to link the landslide area to each class and landslide area in the region.
Results
The results obtained from the paired comparison of the effective factors in the occurrence of landslide show that the relative preference of the factors include the factor of arias intensity, friction angle, slope, adhesion, aspect, height and curvature of the amplitude. The greatest influence on the sub-criteria for the sub-criteria is 10-11.54, which is related to the arias factor and also the lowest effect for the sub-standard of the domain curvature factor. Also, according to the zoning maps, in the first model, 73% and in the second model, 57% of the surface area are very high and very high risk areas, which indicates the high sensitivity of the study area to the earthquake-induced earthquake phenomenon.
According to the results obtained from the verification and evaluation of the models and comparison of the mapped data with the hierarchical analysis method (using expert knowledge and data) and a method that uses only expert knowledge, the map is derived from a method where bundles of knowledge and data are used simultaneously, in order to weigh the parameters, it is more in line with the map of the landing list of the region.
Conclusion
According to the results obtained from the review and evaluation of the two models in a method in which knowledge and data were used together, the QS value was 0.40 and the accuracy of the method (P) was 0.016. However, in a method in which only the expert judgment used to weigh the criteria and sub-criteria, the sum of the quality and accuracy of the method were calculated to be 0.37 and 0.006, respectively. Hierarchical analysis method, in which the benchmarks and sub-criteria of benchmark knowledge and data are used together, have a better performance than the other model, and the results are closer to reality. In addition, it also works better in distinguishing between high and high risk areas../files/site1/files/124/5rajabi%DA%86%DA%A9%DB%8C%D8%AF%D9%87.pdf
Navid Sohrabi, Mehdi Khodaparast,
Volume 12, Issue 4 (Vol. 12, No. 4 2018)
Abstract

Introduction
In many areas of the world, the mechanical properties of soils for utilization of land are not sufficient. For improvement of these lands, soil stabilization such as compacting, installation of nails, elders of piles, mixing soil with lime or cement before or during constructions on the surface or inside of the ground can be useful. Microbially induced carbonate precipitation (MICP), due to its versatility and stable performance, has been recently attracted the attention of many researchers in the field of the geotechnical engineering around the world. MICP is a biological technique that is naturally caused to create a cementation agent, which is known as calcium carbonate or calcite by controlling the metabolism of bacteria. Although there are many biological processes that can be lead to MICP, but the using of urea hydrolysis by bacteria is commonly used more. In this method, aerobic bacteria with the enriched urease enzymes inject into the soil. Hydrolysis of urea occurs when the bacteria speeds up the hydrolysis reaction to produce ammonium and carbonate ions. In the presence of soluble calcium ions, carbonate ions are precipitated and formed the calcium carbonate crystals. When these crystals are formed on a grain of soil or like a bridge between them, they prevent the movement of grains and thus improve the mechanical and geotechnical properties of the soil.
Material and methods
In the present study, the effect of increasing fines on the improvement of Anzali sandy soil, and soil resistance parameters for improving the clean sand and its mixtures with a fine grained cohesive soil and a fine grained cohesionless soil separately in a percentage weight of 30 by MICP and using a small scale of direct shear test (6×6) have been investigated. In the present study the sandy soil was collected from the coast of Bandar Anzali Free Zone and for the preparation of samples of clayey sand and silty sand, Kaolinite clay soils and Firouzkooh broken silt were used, respectively. Anzali sand is poorly graded and had a rounded corner with an average particle size of 0.2 mm, somewhat, sharpening cores are also found in its granulation. In addition, its fine grained content is very small (less than 1%). The Kaolinite clay is also labeled with a liquid limit of 40, a plastic limit of 25, and a plasticity index of 15 as an inorganic clay (CL). The used microorganism in this study is urease positive Sporosarcina pasteurii, which is maintained with the number of PTCC1645 at the Center Collective of Industrial Microorganisms of Iran Scientific and Research Organization. The bacterium was cultured in a culture medium containing 20 g/l yeast extract and 10 g/l ammonium chloride at pH 9 under aerobic conditions in incubator shaker machine at 150 rpm and temperature of 30 °C. The organism was grown to late exponential/early stationary phase and stored at 4 °C before injection in samples. A solution of calcium chloride and urea with a molar ratio of one is also used as a cementation solution. With the direct shear test (6cm×6cm) as a benchmarking of the shear strength in the before and after improvement steps, molds fitted with a shear box made of the galvanized sheet with a thickness of 0.6 mm and it consists of two main parts, the body,  in the middle of which an exhaust pipe was embedded in the injector waste fluid. At the bottom of the samples, a layer of filter paper was placed in order to prevent soil washes, and then all samples with a thickness of 2 cm, with a relative density of 30% at the same weight and height were pressed. In the upper part of the samples, a layer of filter paper is similarly used to prevent the discontinuity of soil particles when injected biological materials are used. Biological solutions are injected from the top to the specimens and allowed to penetrate under the influence of gravitational and capillary forces in the sample and discharge the inhaled fluid from the exhaust pipe. The criterion for determining the volume of the solution to inject into each sample is the pure volume (PV) of soil. The preparation process of the samples was initiated by injection of a PV water unit, followed by a two-layer mixture of bacterial suspensions and cementation solutions, each with a volume of one PV, and then for biological reactions, 24 hours to the sample at laboratory temperature (25 ± 2) is given. After the time of incubation, the solution of cementation is injected into the sample for a period of three days and every 24 hours. The processing time of samples is also considered 28 days. In this study, optical density (OD) was selected as a benchmark for estimating the concentration of bacterial cells in the culture medium, and in all stages of development, and precisely before injection of bacteria suspension into soil samples, it was measured by a spectrophotometer device at 600 nm (OD600) wavelength, which was obtained for all bacterial suspensions in the range of 1.7 to 2 before the injection. To determine the activity of urea bacteria, 1 ml of bacterial suspension was added to nine milliliters of 1.11 molar urea solution, and by immersing the electrode of the electrical conductivity in the solution, its conductivity was recorded for 5 minutes at 20 ± 2 ° C. The rate of urea activity in the pre-treatment stage for all specimens was in the range of 0.8 to 1.23 mS min-1. In order to evaluate the shear strength parameters of soil samples, before and after the improvement operations, a direct shear test was used based on the ASTM D3080 standard. This test was performed for all samples under stresses of 50, 100 and 150 kPa in undrained conditions at a loading speed of 1 mm/min up to a strain of 15%. Also, samples of soil with a moisture content of 7% and a relative density of 30% (as already mentioned) have been restored. SEM analysis was carried out to determine the distribution of sediment between soil particles and EDX analysis in order to identify carbonate calcium sediment formation elements in improved soil samples, by scanning electron microscopy on Anzali sandy soil samples in before and after improvement conditions.
 
 
Conclusions
The effect of the increasing cohesive and cohesionless fines on the bio-treated process of sandy soil is the main subject of this research. For this purpose, three samples of clean sand, sand containing 30% clay and sand mixture with 30% silt in a relative density of 30% were treated with MICP method and their shear strength parameters were evaluated by direct shear test after 28 days of processing. Using the direct shear test and analyses of SEM and EDX data, the results are represented as below:
1.  The microbial sediment of carbonate calcium has greatly improved the resistance properties of all three soil samples.
2. A sample of clayey sand, in spite of a higher improvement compared to the other samples with an average shear strength of 113.7% in comparison to to its untreated state, it has the lowest shear strength among the three improved samples.
3. Increasing the clay content of 30% increases the soil voids. On the other hand, it reduces the friction angle and shear strength of the soil in the pre-treated state and also facilitates easier movement of the bacteria between the pores in the soil. More favorable distribution of sediment calcium carbonate was occurred and, as a result, increased adhesion between soil particles.
4. The increase of cohesionless fine particles creates more bonding points between sand particles and, therefore, calcium carbonate crystals form shorter distances between the soil bridges. As a result, with the end of the improvement process, the shear strength parameters of the sandy soil containing 30% of the silt compared to the clean sand have a higher value.
5. SEM images of the clean sand in both before and after improvement show that the calcium carbonate precipitation occurred with a uniform and thin layer that surrounds sand grains and another part of the sediments formed in the joint of grains.
6. Cube-shaped crystalline sediments confirm that the sediment formed in the soil is a stable type of calcite and that the relative increase in the friction angle of the improvement samples can be attributed to solid particles and multifaceted sediments. Also, the elements of carbon, oxygen, and calcium, which are the main components for the formation of calcium carbonate deposits, have been found in the EDX analysis of improvement sand samples../files/site1/files/124/7sohrabi%DA%86%DA%A9%DB%8C%D8%AF%D9%87.pdf
 
Mr Behrouz Ahmadpour, Dr Masoud Amel Sakhi, Prof Mohsen Kamalian,
Volume 12, Issue 5 (English article specials 2018)
Abstract

Steel sheet pile walls are being widely used as earth retaining systems. Sometimes loose or soft soil layers are located in various depths in an excavation. This issue causes different effects on ground surface displacements, forces and moments acting on sheet piles and struts during excavation procedure, compared with a status that soil is totally uniform. These differences are not exactly considered in conventional design methods of sheet pile walls. In this paper, a deep excavation using finite element method is analyzed. Excavation’s depth is divided into three different layers. One of three layers is a loose soil layer and its position is modeled in three different situations, top, middle and bottom of the model. Obtained results are compared with results of excavation without the loose layer. The pseudo-static analysis is performed by applying 0.3g horizontal acceleration. The results indicate that when a loose layer is located beneath stiffer layers, bending moments acting on sheet pile wall and shear forces increase about (50~100)% and (15~50)%, respectively. Also, the middle loose layer changes the location of maximum lateral deformation of steel sheet pile wall.
 


Prof. Seyed Amirodin Sadrnejad, Dr. Hasan Ghasemzadeh, Mr. Ahmadali Khodaei Ardabili,
Volume 12, Issue 5 (English article specials 2018)
Abstract

In a perforated well, fluids enter the wellbore through arrays of perforation tunnels. These perforations are typically distributed in a helical pattern around the wellbore. Available numerical models to simulate production flow into cased-and-perforated vertical wells have complicated boundary conditions or suffer from high computational costs. This paper presents a simple and at the same time efficient finite element model to simulate flow around a well with helically symmetric perforations. In the proposed model, by taking advantage of the symmetry, only a thickness of perforated interval containing a single perforation tunnel needs to be meshed. Angular phasing between adjacent perforations is considered by applying periodic boundary conditions on the upper and lower boundaries of the representative reservoir thickness. These boundary conditions involve periodic-pressure and periodic-velocity parts. Unlike the periodic-pressure part, the method of imposing the periodic-velocity condition within a single-variable flow problem is rather vague. In this regard, it is proved that in the proposed model, periodic-velocity condition is automatically satisfied in a weak sense. The accuracy and the computational efficiency of the proposed model are verified through comparison with available models. The model results, in terms of skin factor, are compared with the common semi-analytical model as well, and good agreement is obtained. The proposed model can readily be used as a numerical tool to study inflow of wells with helically symmetric perforations.
 


Kazem Saber Chenari, Abolareza Bahremand1, Vahed Berdi Sheikh, Chooghi Bairam Komaki,
Volume 13, Issue 1 (Vol. 13, No. 1 2019)
Abstract

Introduction
One of the main problems in the Golestan province watersheds is the high degree of erosion and soil degradation, so that the equilibrium between the soil process and the soil erosion is unbalanced, and the erosion rate increases from west to east. Among these, the gully erosion and piping have the highest role. Gully is a canal or stream with the headcut with active erosion, sharpened slope and steep walls that results from the destruction of surface flow (usually during or after the occurrence of precipitation), dissolution movements, and small mass movements. The extent of gully in the eastern parts of Golestan province has caused the land degradation of arable land and landscape and has increased the conservation cost and etc. Because of connecting upstream areas of the basin to the downstream areas, gully has particular importance, which provides the possibility of sediment and pollutant transport, road destruction and financial losses to agricultural lands. In order to prevent and control the development of gully processes from a small scale to large one, it is a versatile utility to identify and extract the areas prone to gully erosion.
Due to the high intensity of gully erosion and its increasing growth in the Gharnaveh watershed, the Garnaveh River has an unstable status and severe eroded gully, and in some areas it has a great depth and vertical lateral walls, as well. Therefore, in this research, the watershed of Garnaveh was selected to prepare the risk areas of gully erosion.
The aim of this research is to determine Gully Erosion Hazard zoning using Frequency Ratio and Gupta & Joshi methods (Gully Nominal Risk Factor-GNRF) in the Garnaveh watershed (Golestan province). Ultimately, the accuracy of the model has been evaluated using quality sum method and Kappa coefficient.
Material and methods
The study area is located in the northern part of Iran, Golestan province. The Garnaveh watershed with an area of about 78430 hectares lies between longitudes 370360 E and 414472 E, and latitudes of 4183819 N and 4155267 N (UTM Zone 40).
At first, gully erosion inventory map with the scale of 1:75,000 (dependent variable) for the Gharnaveh watershed has been prepared using multiple field surveys and satellite images. From total gullies, 70% have been selected randomly for building gully erosion hazard zoning model and the remaining ones (30%) have been used to validate the provided model.
In this research, seven data layers including slope percent, slope aspect, plan curvature, lithology formation, land use types, distance from rivers and distance from roads have been selected as gully erosion controlling factors (covariates/ independent variables) and then they have been digitized in ArcGIS software. The amount of Gully density of each factor class has been calculated from a combination of independent and dependent variables, and the rating of classes have done based on Frequency Ratio and Gully Nominal Risk Factor equations. Finally, the Gully erosion hazard zoning map has been drawn from the summation of weighting maps in ArcGIS. In this map, the value of each pixel is calculated by summing the weights of all the factors in that pixel. The pixel values are categorized based on the natural breaks classifier into very low, low, medium, high and very high hazard zones. Then, an accuracy of zoning map has been evaluated by quality sum method and Kappa coefficient.
Results and discussion
The result of affecting factors classification of the gullies shows that loess deposits formation, rangeland, areas with low distance from road and rivers, northwest aspect, low slope amplitude and concave slopes contain the most susceptibility to gullying. The results of frequency percent comparison of gullies in hazard classes show that from all gully zones in the validation step of the GNRF and frequency ratio models %74.52 and %78.11 of zones are located in the high and very high risk classes, respectively. The result of model validation using the quality sum method and a Kappa coefficient show that the frequency ratio model is a more appropriate model for gully erosion hazard zoning (with the quality sum and a Kappa coefficient of 3 and 0.89, respectively) than the GNRF model (having the quality sum and Kappa coefficient of 1.27 and 0.74, respectively).
Conclusion
In this research, the areas susceptible to gully erosion in the Gharnaveh watershed have been mapped with the frequency ratio and GNRF (for the first time) models. For this purpose, 7 affecting factors (independent variable) and 805 gully zones (dependent variable) were provided to measure the hazard maps of gully erosion. The following results are obtained from this study.
- The geology factors were identified as the most effective factors in the occurrence of gully erosion in the Gharnaveh watershed.
- Based on the gully erosion zoning hazard map of the Gharnaveh watershed, more than 70 percent of gullies are situated in the very high and high hazard classes.
- The produced gully erosion hazard map is useful for planners and engineers to reorganize the areas susceptible to gully erosion hazard, and offers appropriate methods for hazard reduction and management, as well../files/site1/files/131/4Extended_Abstract.pdf
 
Vahid Daneshjoo, Reza Farokhzad,
Volume 13, Issue 1 (Vol. 13, No. 1 2019)
Abstract

Introduction
Nanostructured materials have gained increasing attention of industry and the academia in recent decades, due to their prominent behaviors. In this regard, the building industry is considered to be the major consumer of nanostructured materials in terms of its needs, including strength, resistance, durability and high performance. Studies on nanoscale behavior of cement and concrete to develop new building materials and their applications are of high importance. A typical method for the development of high performance concrete (HPC) often contains various parameters, including the mix of conventional concrete with different types of additives. Nano-Calcium carbonate (Nano-Precipitated Calcium Carbonate) is a nano-sized filler which is used in this research. The results indicate that the higher the optimal content of nano-precipitated calcium carbonate powder, the higher the initial heat of the roller-compacted concrete; also, the resistance of the samples significantly increases over time. However, the level of permeability of roller-compacted concrete decreases by optimal increase of nano-calcium carbonate powder due to its fine grains, filling properties, and high specific level. The results of this study show that the adequate use of this material improves some properties of roller-compacted concrete.
Material and methods
In this study, the content of Nano-calcium carbonate used was selected at 0, 1, 2, 3 and 4 percent replacing a volume of cement consumed in concrete. Type II Portland cement, crushed fluvial sand, and crushed coarse aggregates with a maximum size of 19 mm were used. The aggregates’ grading range in the mix has been selected according to the ACI325-10R. The chemical formula of Nano-calcium carbonate powder is CaCo3 and the average particle size is between 15-40 nm
According to the roller-compacted concrete specifications, 5 mix designs have been used with different proportions of stone materials in preparing of concrete. The samples were made on a vibrating table and in the cylindrical molds of 15 × 30 cm according to ASTM C1176 standard.
By increasing the cement grade, the slope of the Vebe curve increases, which means an increase in speed and reduction in efficiency over time in higher grades. Increasing the cement grade from 275 to 300 kg/m3 leads to increased Vebe time. In other words, it can be said that the efficiency is reduced at a lower rate in lower grades of new roller-compacted concrete mix. The Vebe time of the roller-compacted concrete pavement should be between 30-40 s to achieve optimal efficiency. According to the results of Vebe time, the efficiency of the roller-compacted concrete with the grade of 300 kg/m3 has a better functionality than other mixtures and lasted more than others in the 30 to 40 second range. Accordingly, concrete with a grade of 300 kg/m3, is the compressive strength according to this design.
Determining the compressive strength of cylindrical concrete samples of different ages is done according to the ASTM C39/C39M standard. For permeability test, the BS EN 12390-8: 2009 was used in which the sample should be put under pressure of  (0.5±)5 for 72 hours immediately after molding. Determining the tensile strength of concrete cylindrical samples at different ages is done according to the ASTM C496 standard. The peak is obtained using the XRD analysis of the crystallite size by determining the width of the peaks. In interpreting the XRD data, a list of peak resolution and their intensities is observed. To determine the elemental composition of materials, a non-destructive analytical technique is used by X-ray which is so-called XRF (X-ray fluorescence). A scanning electron microscope is a powerful magnification tool and is used to distinguish elements.
Results and discussion
The results indicate that the increased Vebe time occurs by an increase in the percentage of nano-calcium carbonate. In terms of the compressive strength of cylindrical roller-compacted concrete samples, 2% of nano-calcium carbonate at the ages of 7, 28, and 90 days has been effective in increasing compressive strength in higher ages. Such that, at the ages of 28 and 90 days, it is increased by 12% and 15 % compared to the control sample, respectively. The nano content increases over 15% causes decreased compressive strength and thus had negative effects on the rheological properties of the roller-compacted concrete. In terms of tensile strength of the cylindrical roller-compacted concrete samples, 2% of nano-calcium carbonate at the ages of 7, 28 and 90 days has been effective in increasing compressive strength in higher ages, such that at the ages of 7, 28 and 90 days, it has been increased by 25%, 30% and 30 % compared to the control sample, respectively. However, it can also be concluded that the excessive increase has partly reduced the tensile strength.
The variation of the permeability coefficient is a function of concrete porosity and water penetration in the roller-compacted concrete. Also, there are significant changes in the concrete permeability coefficient by adding different percentages of nano-calcium carbonate to concrete.
Adding nano-calcium carbonate up to 2% of cement weight to the roller-compacted concrete reduces the permeability coefficient of the roller-compacted concrete. One of the reasons for this phenomenon is capillary interstice filling in the roller-compacted concrete. Moreover, the nano-calcium carbonate increase of over 2% of cement weight raises the permeability of the roller-compacted concrete.
Adding 4% of nano-calcium carbonate to the roller-compacted concrete pattern increases the intensity of the peaks in the XRD test. Given that the average crystallite size is obtained from full width at half height of the peaks, by increasing the peaks’ intensity and their width at half height of the peaks, we get smaller crystallite size. Also, by adding 4% of nano-calcium carbonate, the widths of the peaks are increased, which means smaller crystals and increased crystallite inner tension.
Conclusion
Nano-calcium carbonate, due to its special features, including a high specific surface area, has a good performance in improving the mechanical properties and durability of the roller-compacted concrete, if it is used at a certain and optimal amount. The roller-compacted concrete with the grade of 300 kg / m3 has better functionality than other mixtures, and lasted more in the 30 to 40 second range.
The mix design containing 2% of nano-calcium carbonate replacing cement, has the highest compressive strength at the age of 7 days and shows 4% increase in resistance compared to a control sample at the age of 7 days. The mix design containing 2% nano-calcium carbonate has the highest compressive strength at the age of 28 days and shows 12% increase in resistance compared to a control sample at this age and improved the compressive strength. The mix design containing 2% nano-calcium carbonate has the highest compressive strength at the age of 90 days and shows 15% increase in resistance compared to a control sample at this age. The mix design including 3% of nano-calcium carbonate replacing cement, has the highest tensile strength at the age of 7 days, and shows 25% increase in resistance compared to a control sample at the same age. The mix design containing 2% of nano-calcium carbonate replacing cement, has the highest tensile strength at the age of 28 days and shows 30% increase in resistance compared to a control sample at the same age. The mix design containing 2% of nano-calcium carbonate replacing cement, has the highest tensile strength at the age of 90 days and shows 30% increase in resistance compared to a control sample at the same age. ./files/site1/files/131/3Extended_Abstract.pdf
 
Behrooz Samadian, Ali Fakher,
Volume 13, Issue 1 (Vol. 13, No. 1 2019)
Abstract

Introduction
Geotechnical investigations merely through boring and engineering experiments are considered a difficult task as they are highly costly and time-consuming. The identification of large areas initially requires geological studies followed by the inclusion of geotechnical information. Finally, a geological and geotechnical classification is prepared for the entire area. This type of classifications is employed in strategic urban planning and quick selection of geotechnical variables in small-scale projects. The present research performed the steps involved in these investigations and classifications for the city of Sanandaj, Iran. Hence, the geological-geotechnical classification of the city of Sanandaj was presented by integrating the geological information of this city with the geotechnical data obtained from drilled boreholes as well as multiple wells at different locations in this city.
Materials and Methods
This study was conducted on the city of Sanandaj in six steps. The steps involved and their respective objectives are given in summary in Table 1.
Discussion
This study is applicable to those regions with insufficient information on their boreholes. The present study used only 211 boreholes, the distance
Table1. Steps involved in this study
Objective or result Title Step
Identifying the general geological characteristics General geological investigation of the considered region 1
Determining the rock units and soil layers as well as their outcrops and investigating their appearance Determining the appearance of the layers through field investigations 2
Determining the layer types and drawing the longitudinal and lateral profiles Identifying subsurface layers 3
Determining the characteristics of geological units and their origin of emergence Geological classification based on the steps involved in formation of units 4
a)Collecting the available information, b) controlling the available information, c) completing the information Determining the geotechnical attributes of geological units 5
a) Presenting geological-geotechnical classification, b) presenting geological identification criteria to determine the type of a given unit at the site of the project Presenting a geological-geotechnical classification for the considered region 6
between which was greater than 5 km in some areas of the Sanandaj city. Hence, although no sufficient information was available on many areas of Sanandaj, the proposed method in this study was able to identify the geotechnical attributes of all soil layers and rock units. This study emphasizes on geological and geotechnical classification and presents a step-by-step method to systematically relate geological and geotechnical studies. By integrating these classifications, geotechnical identification of extensive regions such as urban areas can be facilitated even if the number of boreholes is insufficient. Moreover, simple identification criteria can be extracted from this method, through which the engineering attributes of the layers at each point can be determined. This method can be used as an optimal and economical method for geotechnical identification of extensive areas.
Conclusion
The following summaries can be concluded from this study:
-The step-by-step procedure of integrating geological and geotechnical information was described, through which the geological-geotechnical classification for this city was obtained.
-The geological units identified for Sanandaj were shale, limestone, andesite, and Quaternary, which includes layers of alluvial clay, residual clay, and sand and gravel. The extent and distribution of each of the aforementioned units in Sanandaj were identified and plotted. Moreover, the physical and mechanical characteristics of each of the units as well as their geotechnical hazards were determined and presented.
-In this study, simple geotechnical criteria such as faults, altitude level, and distance from river were identified. These parameters were effective in identification of geological units in Sanandaj../files/site1/files/131/5Extended_Abstract.pdf
 
Kazem Bahrami1, Seyed Mahmoud Fatemi Aghda, Ali Noorzad, Mehdi Talkhablou,
Volume 13, Issue 2 (Vol. 13, No. 2 2019)
Abstract

Aggregates are one of the high demand building materials in construction of structures and their characteristics have important effects on durability and permanence of projects. Abrasion resistance is one of the important features of aggregates that their utilization in concrete and asphalt are affected by texture and lithology of them. As rock consisted of harder minerals have higher abrasion resistance like igneous rocks, due to more siliceous minerals. More varieties in mineralogy compound usually lead to increase in aggregate abrasion. Aggregates that are contained of different minerals usually have less abrasion resistance. Porosity usually decreases the resistance abrasion. In addition to lithological properties, the environment where aggregates are deposited is important in determining resistance-related parameters of aggregates.
Rivers, alluvial fans, and taluses are the main environments where aggregates are deposited. Geological processes, such as weathering and particle movement may cause changes in natural aggregates, hence affecting their abrasion and impact resistance. Rock weathering can results in increasing porosity, producing minerals that are weaker in comparison to their original rock.
In the process of particles transport by stream water, weak parts of aggregates will be omitted. The present study is focused on the relationship between geology medium and the weight loss of aggregate in Los Angeles test. 
Methodology
Considering that lithology features in aggregates resistance against abrasion have an important role, in order to examine the effect of various geology environments in abrasion resistance of aggregates, the medium should be chosen having similar lithology. Therefore, the north of Damavand and the south of Daneh Khoshk anticline (north of Dire plain) were firstly chosen by using geology map, satellites images and field study. Damavand zone consists of trachyte and trachy-andesite volcanic rocks. These rocks cover the whole area around the Damavand peak. Also, Daneh Khoshk anticline is covered by thick Asmari formation. The selected environment are in the length of each other. Such that taluses feed alluvial fan and alluvial fans feed rivers. Samples were collected from different area of southern part of anticline. 10 river area, 12 alluvial fan and 6 taluses in the south-west area of Daneh Khoshk anticline (north of Dire plain) were chosen. Los Angeles test has been done according to standard A method ASTM D2216-10, 1990 on samples and the results were analyzed by analogous analyzer.
Results and discussion
Results show that porosity and micro-crack percentage increase, respectively in accumulated aggregate in river, alluvial fans and taluses areas. Also, porosity and micro-crack in various alluvial fans is different and is influenced by the area and length of main channel of alluvial fans’ catchment. The porosity decreases by the increase in the length of channel and area of alluvial fans’ catchment.
The percentages of aggregate weight loss in talus, alluvial fan and river areas decreases, respectively. Based on the obtained results, the lowest rates of weight loss belong to river environments (23.7 % in Daneh Khoshk and 42% in Damavand) whereas the highest rates of weight loss belong to taluses (49.3% in Daneh Khoshk and 48% in Damavand). The alluvial fans have an average state. Another noticeable point is the high weight loss in Los Angeles test in Damavand aggregate. Due to having harder mineral, igneous aggregate have more abrasion resistance, but this research illustrates that the weight loss resulting from Los Angeles test in these aggregates is high. This is because of virtues texture that weakness against the impact as well as their high porosity.
Conclusion
The result of this research indicates that the volume of aggregate weight loss in Los Angeles test is related to aggregate accumulation environment. The extent of aggregate abrasion resistance is lowest in talus medium and increases in alluvial fan and river environment, respectively. The difference in aggregate abrasion resistance in various areas result from geology process differences that applies to aggregates in various environment. The extent of caring particles in talus environment is very low and the type of movement is mass or sliding type in these media, micro-crack and weak parts remains within aggregates. The surface of micro crack is weak such that breaks easily in Los Angeles test due to the pressure results from the impact of aggregate, as well as the impact of steel ball on aggregate leading to aggregate breakages. Aggregates move more distances in alluvial fan and river. Aggregate strike together in riverbed and alluvial fan yielding to aggregates breakages from micro-cracks. As the movement distance increases, aggregates approach more to intact rock. During the particles move, the weathered and weak parts are damaged by aggregate abrasion to riverbeds and alluvial fan, and more resistant and harder aggregates remain. As the water current increases, the aggregates impact each other harder, more resistant micro-crack breakages and this change leads to decrease the weight loss in Los Angeles test.
./files/site1/files/132/1Extended_Abstracts.pdf
Ahmad Khorsandi Aghai,
Volume 13, Issue 3 (Vol. 13, No. 3 2019)
Abstract

In this research, the relationship and reaction between quantitative and qualitative Shahre Rye spring’s karstic water (Cheshme Ali) and spring’s adjacent alluvium aquifer have been considered to determine the relationship between alluvial and karstic aquifers and to study the connections between the two different groundwater environments. The results of the present research suggest geological conditions, hydrogeology and different hydraulic condition between Cheshme Ali karstic water with its surrounding alluvium’s aquifer. However the study results show the lack of a hydraulic connection between the two different groundwater environments (karst and alluvium) that are formed by north Rye fault.
Introduction
There have been many studies in the field of the present research, some of which are mentioned below.
(Tobarov, 1966). The N. Massei et al. (2002). (Robert E. 2005). (Ezatollah Raeisi 2008). (Cholami et al. 2008). (N. Goldscheider and C. Neukum 2010). (Dusan Polomcic et al. 2013).
The aim of this research is to identify the hydraulic relation between the alluvial aquifer and the karstic aquifer of the Cheshme Ali, during which the geographic, topographic and geologic situations and the changes in water discharge of Cheshme Ali and the changes in water table of the observation wells of the aquifer to the north of the spring have been reviewed simultaneously.
The results indicate a lack of relation between the alluvial aquifer and the karstic aquifer of the Cheshme Ali in Shahre Rye.
The general specification of the study area
The surface area of Shahre Rye equals to 2,293 km2 and the city is limited to the north by Tehran, to the south by Qom, to the east by Varamin and Pakdasht and to the west by Islamshahr, Robat Karim and Zarandieh (Fig. 1). The Cheshme Ali is located in the eastern parts of the city and southeast of Tehran. From a geographic point of view, the Cheshme Ali spring is situated in the southern part of the Cheshme Ali hill, and after leaving the ground, the spring's water flows to the south of Shahre Rye.
Methodology
1. Topography
The topographic specifications of the Cheshme Ali and its surrounding are as follows:
The highest points of the Cheshme Ali's surroundings are the Sepaye Hills with an altitude of 2,085 m above the sea, which are located to the east of Cheshme Ali. The height of Bibi Shahbanoo hill to the southeast of Cheshme Ali is about 1,498 m. The altitude of the northern hill of Cheshme Ali, where the spring is located is about 1,077 m and the lower sloped land surrounding it have an altitude of 1,072 m above the sea. This means that the opening of the Cheshme Ali spring is located at 1,072 m above the sea.
2. Geology
From the geological point of view, the existing units around Cheshme Ali of Shahre Rye consist of Precambrian, Mesozoic and Cenozoic sediments and rocks as geological specifications of Cheshme Ali and its surroundings are shown in Fig. 2.
From the structural geology, and geological specifications two geological sections AB, CD Were prepared and presented in Figure 3.
The Figure 3 shows, Cheshme Ali spring appears from Cretaceous thick layered limestone (Tizkooh formation Kt1) and the shahre Rye fault mechanism on either side of layering. However the water flow of cheshme Ali is nearly east – westerly after spring’s openings (A) and then spring water flow direction is to the south (Fig. 4).
The hydrogeology of the spring and the wells
1. The Cheshme Ali in Shahre Rye is a karstic spring, with few hydrogeological specifications that are concluded from the result of geological and hydrogeological review and analysis of the spring’s water quality.                                                           
Therefore, the karstic Cheshme Ali spring has a varied range of discharge which is from medium (25 to 100%) to high (>100%). Moreover in the curves of the spring’s discharge and simultaneous rainfall, shown in figure 5, the peak volume of water discharge of the spring corresponds fully with the peak rainfall, underlining the influence of simultaneous rainfall on the spring.                
The study of the hydrographic makeup of the spring (curve 2) shows the difference in the period between the upward curve (seven and a half months) and the downward curve (four and a half months) underlining the lower permeability of the spring’s intake area versus the grounds conducting spring water to the openings.
2. The hydrogeology of the surrounding wells:
For the purpose of studying the fluctuation of water tables of the observation wells around the spring and in its adjacent alluvial aquifer, the isobaths maps of groundwater level and groundwater table of the spring’s surrounding areas were drawn ( Fig.6). The level of groundwater table to the north of spring is 5.9 m and 6.6 m to the south of it, while the spring water is at ground level. In order to have a better understanding of the potentials of groundwater table in Shahre Rye’s Cheshme Ali and its surrounding environments from south to north, the potential profile is provided in figure 7 using the potential figures of witness wells and the Cheshme Ali spring. In the potential profile, the groundwater level of the Cheshme Ali is higher than the groundwater potential level of the witness wells, which seems to suggest the recharge of the plain by the spring.
The review of the groundwater quality in wells and the Cheshme Ali spring
The groundwater quality characters of the Cheshme Ali and the wells to the north and south of the spring are presented in table 2,that shows three differences and similarities in the results of the chemical analysis of water from Cheshme Ali and from wells located to the north and the south of the spring. The difference between the chemical composition of water from the spring and the chemical composition of the well located to the north is considerably more than the difference between the chemical compositions of the spring and the well located to the south.
Summary and conclusion
Based on the geological studies of this research, the Cheshme Ali spring in Shahre Rye appears from the Karstic Tizkooh formation (Fig. 2) and the geological structure shows a northerly direction for the slopes of the layers in Tizkooh formation, and an east-westerly direction for the appearance of the spring water (Fig. 3 and Fig. 9). The spring’s flow is disseminated and the spring is of Karstic - fault type (table 1). The discharge of Cheshme Ali corresponds entirely to rainfall and is influenced a lot by it (Fig. 5). The condition of groundwater table of the well and the spring (Fig. 6, A) and the water level potential of the spring and its surrounding wells underlines the existence of two different hydraulic environments (Fig. 6, B). Moreover, from the aspect of potential groundwater column, there is a large difference between the groundwater table potential of the spring and the potentials of the two wells to the north and south of the spring (Fig. 7and8). From a qualitative aspect, the quality of spring water differs greatly from the quality of water from the wells located to the north and south (table 2).
The results of this research are as follows:
1. The study of geologic, structural geology and the geological section shows the water in the Cheshme Ali of Shahre Rye is originating from the Karstic formation of Tizkooh that layers sloping are to the north, the spring water appears from the site of the Rye fault and then flows to the west.
2. The studies have proven that Cheshme Ali to be a Karstic – fault spring with disseminated flow, whose discharge is influenced by rainfall and condition of groundwater level and the table which underlines the alluvial aquifer shows lack of relation between two alluvial and karstic aquifers.
3. The water quality analyses show a great difference between the specifications of the spring water and its surrounding wells groundwater.
4- The north Rye fault mechanism are formed two different groundwater environment ( Karstic and alluvium) and however different groundwater conditions between north and south of alluvium.
Aref Alipour, Mojtaba Mokhtarian,
Volume 13, Issue 4 (Vol. 13, No. 4 2019)
Abstract

Introduction
The main objective of this contribution is to focus on the portion of the comminution process which deals with the prediction of the energy consumption due to the comminution portion of the milling processes.
The comminution energy in mineral processing and cement industry is usually determined by empirical Bond Work Index (BWI), regardless of the mechanical properties of a rock. The BWI is a measure of ore resistance against grinding and is determined by using the Bond grindability test. Determining the BWI value is quite complicated and time consuming. Its value constitutes ore characteristic and is used for industrial commination plants designing and optimization. The BWI is defined as the calculated specific energy (kW h/t) applied in reducing material of infinite particle size to 80% passing 100 µm. The higher the value for BWI, the more energy is required to grind a material in a ball mill. The energy consumed in the process of comminution depends on both the mechanism of comminution and the mechanical properties of the materials being ground. It is interesting to study the effect of the essential ones of these properties on the energy efficiency of grinding process.
Material and methods
Several attempts have been made to obtain and optimize the comminution energy. An efficient Response Surface Method, (RSM)-based method for the BWI approximate value determination, which is based on physico-mechanical tests, is presented in this paper.
BWI and some physico-mechanical tests on 8 typical rock samples and its correlation are studied; it would be beneficial to examine this relation based on physical concept. The database including Uniaxial Compressive Strength (UCS), Abrasion (AT), Hardness (HT) and Modulus of Elasticity (ME) are assembled by collecting data from Haffez experiments.
Results and discussion
The determination of the BWI from RSM- based multivariate model is almost matched with measured Bond’s work index. As a result of analysis the best equation obtained from RSM-based model is formulized in Equation 1:
                                      (1)
Standard statistical evaluation criteria are used to evaluate the performances of predictive models.
Conclusion
The performance of the estimator models can be controlled by R2, VAF, RMSE, MAPE, VARE and MEDAE. The RSM- based model with higher VAF as well as lower RMSE, MAPE, VARE, MEDAE shows better performance in comparison to the Haffez single-variable models. AT and ME have the greatest effect on the value of BWI; and also HT has the least impact../files/site1/files/134/6.pdf
Maryam Mokhtari, Kazem Barkhordari, Saeid Abbasi Karafshani,
Volume 13, Issue 5 (English article specials 2019)
Abstract

In recent years, with the growing use of the nailing method for stabilizing excavation walls, there has been a need for a comprehensive investigation of the behavior of this method. In the  previous studies, the behavior of nailed walls has been investigated in static and dynamic states and under different conditions. However, due to the different feature of near-field ground motions, it is  necessary to study the effect of these motions on the behavior of the nailed walls. Near-fault ground motion is significantly affected by the earthquake record direction and the rupture mechanism. So, in this study, to compare the effects of near-field and far-field ground motions, a two-dimensional (2D) soil- nailed wall was considered. PLAXIS 2D was used for the modeling of the soil-nailed wall system. An excavation with a dimension of 10 meters in height was taken into the account. In this study, 10 records (Five fault-normal near-field ground motion records and five far-field ground motion records), were recorded  on the rock and  applied to the model. These ground motion records were derived from the near-fault ground motion record set used by Baker. These records were scaled to the Peak Ground Acceleration (PGA) of 0.35g and then applied to the bottom of the finite element models. Mohr-Coulomb model was then used to describe the soil behavior, and Elasto-plastic model was employed for the nails. A damping ratio of 0.05 was considered at the fundamental periods of the soil layer. The results showed that the  generated values of bending moment, shear force and axial force in nails under the effect of the near-fault ground motions were  more than those in the far-ault ground motions. These values were  almost equal to 23% for the maximum bending moment, 30% for the  shear force,  and 22% for the axial force. The created displacement under the effect of near-fault ground motions was  more than that in the far-fault since a higher energy was  applied to the model in the near-field ground motions during a short time (pulse-like ground motions). In contrast, in the far-fault ground motions, due to the more uniform distribution of energy during the record, such pulse-like displacements were not observed in the system response. Increasing in nail length and soil densification, decreases the displacement of the soil-nailed wall but does not change the general behavior of the soil under the effect of near-field ground motions. Based on the obtained results, for a constant PGA, there were  positive correlations between the values of the  maximum displacement on the top of the wall and  the PGV values of near-fault ground motion records. However, the mentioned correlations were  not observed in the case of far-fault ground motions.



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