ebrahim asghari kaljahi

With the expansion of the petroleum industry and the aging of facilities and pipelines, oil spills are becoming more frequent. In addition to environmental impacts, oil spills can cause changes in the plasticity and dispersivity of soils. To investigate the potential for dispersion in fine-grained soils due to oil leakage, soil samples were collected from the Shazand Refinery area in Arak and mixed with 0, 5, 10, 15, and 20% by weight crude oil. Specimens were prepared at the maximum dry density obtained from the Proctor compaction test and, after curing, pinhole and double hydrometer tests were conducted. The results of the mentioned tests showed that the fine-grained soil tends to disperse with the addition of up to 15% oil, and this dispersion increases with further increases to 20%. Changes in the soil fabric with increasing oil content were investigated using scanning electron microscopy (SEM) images, and the results showed that the dispersion of soil particles increased with increasing oil content.

With the expansion of oil industries, the leakage of oil materials increases. In addition to the negative effects of the environment, the oil leakage causes changes in the physical and geotechnical properties of the soil. These changes in granular soils are in the form of changes in the physical properties and structure of the soil, which leads to a decrease in the bearing capacity and an increase in the settlement of the soil under the foundation. In order to investigate the geotechnical behavior of fine-grained soils due to oil infiltration, a soil sample was taken from the Shazand Arak Refinery area and mixed with 0-5-10-15-20 percent crude oil by weight and remolded with a density of 90 percent of the maximum density (Proctor method) has been subjected to various physical and mechanical tests. Of course, the plastic index has a decreasing trend with the increase of the amount of crude oil. In the compaction test, the maximum dry unit weight of the soil increases with the addition of crude oil and the optimum moisture content decreases with the increase of the amount of crude oil up to 10% and then increases. In addition, the addition of oil generally reduces the permeability coefficient of the soil. Increasing the amount of oil has a different effect on soil consolidation, and the coefficient of soil consolidation increases with increasing the amount of oil. In addition, the uniaxial compressive strength of the soil decreases with the increase of the oil content.

The optimum operation of an open pit mine needs special attention to geotechnical problems including slopes stability. Such investigations should be performed continuously, and the obtained results be used in mine designing and also development studies. There are various types of factors affecting the instability problems of mine slopes and should be identified and investigated during risk assessment process. In this research, an attempt was made to identify the most important factors related to instability of slopes of Sungun copper mine, then rank factors based on their importance. For this purpose, Fuzzy Analytical Hierarchy process (FAHP) has been used. At first, using a questionnaire experts were interviewed and on this basis the most important risk factors defined in 3 layers, then the Hierarchal structure of problem was drawn. Then, FAHP was used to calculate the relative weight of factors affecting risk of slope instability and to determine their importance. The results obtained of field studies and also long term plans for slope controlling were compared with FAHP method results. On this basis, delay in mining operations (Layer 1), extended failure (more than a bench) (Layer 2), and discontinuities (Faults & Joints) (Layer 3) were defined as factors with high importance during risk assessment of slopes instability of Sungun copper mine.

The soil of the Arvand free zone in the north of Khorramshahr is fine cohesive and cannot be used in earth works. On the other hand, suitable materials for this purpose (coarse-grained soils) are located at the farther distances which a considerable cost requires. In this regard, it is trying to improve the soil with lime and furnace steel slag. This study is focused on improvement of the fine-grained soil by adding various contents of lime and furnace steel slag. For this purpose, after sampling and performance of compaction tests, different amounts of slag (10, 20 and 30% by weight of dry soil) and lime (2, 4 and 6% by weight of dry soil) were added to the soil and after curing for 28 days, the effect of additives on the physical and mechanical properties of soil was investigated by using several tests such as Atterberg limits, compaction, uniaxial compressive strength (UCS) and CBR as soaked and unsoaked. Based on USCS classification the study soil is CL, its plasticity index is about 25% and sulphate ion content is more than 0.5%. Experimental results show that by adding slag and lime at different contents to soil, mechanical properties of soil improve dramatically, so plastic index of soil decreased and UCS and CBR has been increased. Also, the maximum dry unit weight of soil increases and the optimum moisture content decreases. The test results also indicate that the effect of lime on soil is higher than slag and the effect of slag for less than 35% is not considerable, however the test result of unsoaked CBR show that the bearing of soil increase in the more than slag content 20% is significant. According to the previous studies, due to the relatively high sulphate ion content in the soil, the use of lime alone is inappropriate and the slag can only physically improve soil conditions but also chemically prevent the formation of large volume minerals (like Ettringite) by the reaction of lime with soil sulphate ion.

Shear wave velocity structure of the surficial layer of the earth is one of the requirements in many of site investigation programs. Conventional methods, especially in sites with thick alluvial layers, have limitations for this purpose. In this study, single-station measurement of micro-tremors and surface-wave ellipticity inversion were used to identification of soil structure. The study site is located in the south of Tehran and has a considerable thickness of soft alluvial layers. The ellipticity ratio was obtained using Geopsy software employing the time-frequency analysis method. Due to the uniformity of the subsurface layers of the site, the mean ellipticity ratio curve of the four seismic measurements stations was used to inversion and extraction of the shear wave velocity structure. Due to the uncertainty in the inversion process and to investigate the convergence and stability of the solutions, five different initial models are considered and the inversion process has been repeated 3 times in each model. There is a very little error in inversion results, where they show that the seismic bedrock exists at a depth of about 100 meters. Also, different models have good convergence indicating the reliability of the method used to derive the shear wave velocity structure.

Uncontrolled urban expansion in country cause to increasing of waste production in the cities and became to an important issue despite the progress of science and technology. The purpose of this study is to investigate and select a suitable location for landfill in Malekan city.

In this study, the required criteria including lithology, land use, vegetation, soil characteristics, topography (slope), distances from urban areas and away from the main road, the main and secondary canals, residential areas, wells and aqueducts, faults have been identified and collected. To form a pair wise comparison matrix and the weight of information layers determined by using of the Expert Choice 11 software and analytic hierarchy process. Then the appropriate zones have been modeled by overlaying of different layers in GIS media.

It was found that the current waste disposal site of Malekan city does not have sufficient conditions for waste disposal and in order to select a suitable location, in addition to addressing the impact of the included criteria, it is necessary to use field visits and environmental assessments to finally select the most suitable place for landfilling.

As a result, 8 zones have been selected that 4 of them were eliminated based on field visits. Finally in order to planning of the studied area waste, the candidate zones were evaluated by the Leopold matrix and finally the zone number 4 located on the east of Qalejogh village has been selected as a best location for landfill of Malekan urban waste.

In this study, some samples of bed sediments from Rasht rivers were obtained and 19 organochlorine pesticides (OCPs) were determined for specifying the contamination profiles, distribution characteristics, effective factors and hazard of carcinogenic compounds. OCPs as Persistent Organic Pollutants (POPS) haskhown vast distribution, persistence and accumulation in the environment. Their high toxicity to humans and non-target organisms are a significant threat to human health and biodiversity.

Identify and determine the concentrations of organochlorine pesticides analysis were conducted on bed sediment samples by liquid-liquid micro extraction method and then by gas chromatography flame ionization (GC-FID) and via external standard calibration curve drawing.

Based on the analysis, total concentration of OCPs is in the range of 2.6-60.2 ng/g, with an average of 20 ng/g. The main sources of pollution are Heptachlor, HCHs, DDTs and Endosulfans and highest contamination of the dominant pollutant DDE isomers belonges to sediments of Pir Bazar River.

The results are showed that there were various amounts of new and past entries. The analysis shows that the potential source of high levels of DDTs and HCHs residues of pesticides returns to the pastconsumptions.

With regard to drying of Urmia Lake, and an extensive unloading from the earth’s crust, due to the loss of water from the lake surface, the evaluation of b-value, and the probable increase of earthquakes, has been investigated in this study. The evaluation of b-value variations due to the loss of water from the lake’s body, represents a decrease in b-value after water level dropping in the lake, subsequent unloading about 20 Milliard tones, and the increase of stress in the study area. Furthermore, the water level change-seismicity diagram, including 1990-2017 data, is clearly show an increase in seismicity and its relation with the lake water level. Research of the radius of the b-value variations have shown that Van M=7.5, 2011 earthquake and Ahar and Varzghan M=6.4, 2010, earthquakes, are the Induce earthquakes due to the loss of water of Urmia Lake.

Soil electrical resistivity is an easy indicator of soil corrosion potential assessment. In order to investigate the soil corrosion in an industrial zone on the margin of the Meyghan salt lake (Kheyr-Abad industrial town), the electrical resistivity was measured by Miller box in laboratory considering different conditions in terms of moisture content. Soils in the region are generally fine-grained and typically are from clay type (CL/CH) according to USCS. In the minimum considered moisture content for the test, which correspond to the dry season, the soils of the study area have the moderate to the severe corrosive potential that increases to the Meyghan lake side. The corrosion potential pattern in superficial soils (0 to 5 m) follows northeastern to southwest waterway channels and is more homogeneous in the deeper parts (5 to 10 m). With increasing moisture content, the electrical resistivity is strongly reduced and in the moisture content of 25%, the corrosion potential of the soils of the study area increases to severe and very severe. Analysis of covariance and correlation coefficient of resistivity decreasing ratio due to increased moisture content with the basic physical properties of soil indicates that the fine grained material content (passing #200) has the most effect on the decreasing of resistivity. The plasticity index, liquid limit and dry density have minor effects in comparison to fine grained material content.

Specifying the soil types and profiling the subsurface soil layers are the excellent examples of CPTu test potentials. In this research, the capability of CPTu test for specifying subsurface soil layers and classification of the sediments in Urmia Lake is investigated. According to previous studies, the sediments of Urmia Lake are commonly fine grained and soft deposits with organic materials. To evaluate the geotechnical parameters of these sediments in Urmia Lake Bridge site, CPTu test was performed and soils were classified applying the results of this test. The results showed that the sediments are mostly composed of clay and silt. To verify the results of CPTu tests for soil classification, the outcomes were compared with the logs of the boreholes and the results of laboratory tests. Comparisons and analysis of findings showed high consistency between the three groups of results; CPTu, boreholes logs, and laboratory tests. Thus, CPTu test can be used, with sufficient confidence and accuracy, to specify and classify the soft soil in lacustrine environments.

For protection of Urmia lake causeway embankment, were used Zanbil and Eslami mountains rocks. Study of these protecting rocks in point of view weathering and demolition are important. The Urmia lake water is very saline and penetrating saline water to rocks texture and salt crystallization is the one of main reasons for rocks weathering and demolition.
In this paper the influence of litological aspects on the strength and durability of volcanic rocks in Urmia Lake Causeway based on field studies and sampling and pertographical studies and some physical and mechanical tests was considered. Rocks of west side of the causeway were obtained from Zanbi Mountain and the rocks of east side of the cause way were obtained from Islamic island. The most of used rocks are consisted of trachyte, andesite, basalt, tephrite, agglomerate and latite. The Islamic island rocks, except andesite, experienced more weathering. Texture properties like particle size and weathering type has more effect on strength and durability on used rocks. Increasing of particle size is causing decrease of strength and durability. The rocks of eastern side of the causeway due to porphyry texture and the occurrence chemical weathering before using in causeway, with high porosity and high water absorption is severe and deeper than weathering of western part rocks. Also the existence of clay minerals that was produced from weathering is caused low density in the Islamic island rocks.

Application of empirical rock-slope engineering classifications to the stability assessment of rock slopes is considered a basic rule that is obeyed by most of the geological engineers around the world. Some of these classification methods that are applied for special design and assessment in geo-structures such as: slope stability, mining activities, excavation, road/railway cutting, etc. are effectively used for reinforcement. The Q-slope classification system which is developed to describe is continuous rock-slope conditions is used for engineering judgment regarding slope stability. This work is focused on the Assalouyeh anticline’s south side which is located in the South Pars Zone (SPZ) in southern Iran. According to the results of the study on 55slopes in the SPZ and implementation of the Q-slope system, a major part of the slopes in terms of sustainability possess critical/uncertain conditions (25 cases), 10 slopes are considered as unstable and 20slopes are classified as stable.

Kandovan historical village, in the vicinity of Osku town is one of the most important attractive sites in East Azerbaijan province which is outstanding and prominent due to the hewn-cut house of rock skirt of the Sahand volcano. This site has been registered in 1998 on the national cultural heritage list of Iran. Kandovan rocky architecture, from geological point of view, is on the surfaces of a thick ignimbrite layer that this layer, due to natural weathering and erosion along the main joints and discontinuities of Kandovan valley, has created conical forms and structures. According to the existing theory, Kandovan village was inhabited and settled in these conical buildings since the Ilkhanid era. Recent developments on rock decay in rock-cut architecture of the Kandovan historical village, have heightened the need for recognizing the role of different factors of weathering process on this site. Therefore, the main objective of this study was to assess the effect of inherent vice as a fundamental factor in deterioration patterns. For this purpose, field and laboratory investigations like sampling and observation, characterization with thin section petrography and X-ray diffraction analyzes, along with the measurement of physical properties and durability of rock in rocky houses, the role of inherent vice rock with intensity of rock mass Kandovan weathering has been done. Nowadays, intensity of decay and weathering in Kandovan village rocks causes of poor living conditions, ruination, and seasonal residence or nonresidential conditions. Based on the rock characterization, water absorption, dry density, total porosity content, saturation coefficient, slake durability and experiment for resistance to freezing-thawing demonstrated that Kandovan ignimbrite rock have poor durability and high sensitive to predisposing factors to deterioration such as wetting and drying and freezing-thawing cycles. The collection of these inherent properties causes of the internal structure to be non-resistance to the tensions arising from the impact of climate cycles. The local climate could be considered (or suggested) as the main reason of weathering and erosion of this rocky architecture.

Solid waste excretion is one of the problems of urbanization. The last element obligated the waste management system and the final destiny all wastes should be discarded is bury. Engineering buried sanitary landfill method of waste disposal in land، is to prevent harm to the environment. Landfills in the case of non-compliance with engineering principles، the ability to create very high pollution in the environment، groundwater، surface water and soil. that is have concerned authorities and the public. One of the major landfill pollution، the infecting is caused by the movement of leachate and groundwater contamination. In the design and management of landfills، leachate control، body construction، drainage channels design، is one of the most important factors. Control and reduce the permeability of the landfill is critical environmental factors. To reduce the permeability of the landfill body used geomembranes، clay layers and other impermeable materials. In this study، the effects of added nanoparticles of clay to landfill body soil to reduced permeability has been investigated. This study located in the Bonab city of East Azarbaijan. The results show that adding 3% to 9% clay nanoparticles caused a significant reduction in soil permeability of landfill body. So that the soil permeability reduced from 3. 25×10-6 to 4. 22× 10-7 centimeter per second in normal leachate conditions. In acidic leachate conditions soil permeability reduced from 3. 83×10-6 to 7. 20× 10-7 centimeter per second and in alkaline or basic leachate conditions from 2. 76×10-6 to 2. 02× 10-7 centimeter per second. Thus، the addition of clay and clay nanoparticles significantly reduce the permeability of landfill body to passing leachate.