Journal of Engineering Geology

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The previous studies underteaken in the region indicate that the Ekhtiarabad and Chah-Darya sinkholes have occurred as a result of dissolution of underground gypsum rocks. Hence, they represent the likelyhood of hidden and threatening caves in the region. The presence of gypsiferous formations having surficial karstic features attest to this supposition. So, in order to determine the possible dissolving sites which may contain caves, the electrical conductivity and evaporite dissolution index maps of Kerman-Baghin aquifier were prepared and matched with groundwater recharge and mobility conditions. Accordingly, four suspected hidden- cave sites were recognized which include a large area around Ekhtiarabad village (as the most suspected site), one spot at the northwest of Baghin Plain and two other areas (south of Baghin and south and southwest or Kabutarkhan). Based on the utilized hydrogeochemical criteria, these last two areas may contain hidden caves, but, due to unsuitable hydrodynamic conditions, the possibility seems weak.

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Awareness of orphological features of rivers is necessary for recognition of river behavior and optimum application of rivers. Overall catchment physiografy have important role for determination factors such as floods, erodible and sediment mutagenicity. In this study in order to understand the behavior of Gamasiab River in the east of Kermanshah province, geomorphologic features of this river has been considered. Study of engineering geomorphologic properties is done by using existing data from previous studies, site visit and field perceptions, study of geology and topography maps. Physiographic properties of catchment, channels morphologic properties and geology conditions in this region have been studied. In this research, several parameters such as average width, environment, area, hydrogeologic coefficient, catchment form, maximum, minimum and mean high, and longitudinal slope has calculated. Also status of drainage density of this river has been investigated and time to focus calculated. Finally this river review and classified according to various classifications for rivers

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Kerman city and its surrounding towns in terms of morphology, consist of a flat alluvial plain of fine silt and clay materials. These sediments have very gentle slope, and constitute the city's main infrastructure. Natural soils generally are structured by passing times due to the influence of environmental factors. Geological factors in Kerman alluviums have caused fine structure after deposition. This paper studies briefly sedimentary basin Kerman, mineralogical and geotechnical properties of the sediments of these areas.semi-qualitative analysis of samples has shown that the mineral deposits in Kerman are mainly illite, chlorite, smectite and calcite. then In order to evaluate the effect of depositional environments and geological history of the engineering properties of the sediments of the Kerman city, A large number of triaxial tests on reconstituted soil moisture greater than LL and different confining pressures, consolidated drained and consolidated undrained is done . In order to evaluate the applicability of soil behavior in normal conditions and the reconstructed curves and stress - strain sensitive soils and soil structure compared with standard sensitivity and then their resistance have been investigated. The results of triaxial tests can be used to interpret the depositional environments and geological history. Comparing the curves of stress - strain in natural and reconstituted samples indicates that in many cases the behavior of intact and reconstituted soils were similar and cementation and soil structure have not been much development. Also Comparison of electron microscopy images of reconstituted and intact samples, not random arrangement of particular structure and soil compaction within the city limits have confirmed. therefore, soils of Kerman are relatively similar by the influence of depositional environments and geological history. these soils have a lot of structure and cementation and are generally compact and strengthening.

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Extended Abstract
Introduction
The presence of potentially toxic elements in the environment and especially in soil has been one of the greatest concerns due to their health implications. Potentially toxic elements from anthropogenic sources tend to be more mobile than those from lithogenic or pedogenic sources.  Generally, the distribution of potentially toxic elements is influenced by the nature of parent materials, climatic conditions, and their relative mobility depending on soil parameters, such as mineralogy, texture and class of soil. In the inhabited, and industrial areas, vicinity to the un-engineered landfills, excess accumulation of toxic elements in surface soils can directly threaten wellbeing of exposed inhabitants via ingestion, inhalation and dermal contact routes. A few studies conducted on risk assessment of potentially toxic elements in soils of Kermanshah province, west of Iran. Soil in the study area is susceptible to contamination by anthropogenic activities in the form of industrial wastewater, agricultural activities, solid waste, runoff, atmospheric deposition and especially un-engineered landfills. The presence of toxic elements in soil around of un-engineered landfills without proper consideration to the environmental protection measures, will certainly lead to a significant environmental hazard in Kermanshah province. Therefore, the main purposes of this study are to evaluate the contamination levels, health risk assessment, and source identification of As, Cd, Cr, Cu, Ni, Pb and Zn in the Gasre Shirin, Gilane Gharb, Paveh, Javanrood, Eslamshahr, Ravansar, Kermanshah and Sanghar un-engineered landfills.
 
Material and methods
     A total of 30 topsoil samples were collected (0-20 cm depth) from the eight un-engineered landfills of the Kermanshah province. In order to achieve a representative sample, composite samples were prepared by mixing the four subsamples taken at each corners of 2×2 m square cell because composite sampling yields homogenized samples for analyses. The subsamples were mixed and a final sample of 1 kg was taken by repeated coning and quartering. To determine background concentration of heavy metals, eight soil samples were collected from areas far from known sources of contamination (40-60 cm depth).
The collected samples were immediately stored in polyethylene bags and air-dried in the laboratory at room temperature. Then, samples passed through a 2mm stainless steel sieve. The <2mm fraction was ground in an agate mortar and pestle and passed through a 63 micron sieve. In order to determine the concentration of As, Cd, Cr, Cu, Ni, Pb and Zn complete dissolution of soil samples (approximately 1 g of each) was carried out using a mixture of HF, HNO₃, HClO₄ and H₂O₂ in a Teflon beaker on sand bath at atmospheric pressure. The concentrations of the selected elements were measured by an accredited commercial laboratory (Zar Azma Laboratory, Iran) using ICP-MS methods. Data quality was ensured through the use of internal duplicates, blanks, and HRM. The precision and accuracy of measurements are 95% and +/-5% respectively.
The assessment of soil contamination was carried out using geochemical indices including contamination factor (CF), modified degree of contamination (mC_d) and enrichment factor (EF). The methodology used for the health risk assessment was based on the guidelines and Exposure Factors Handbook of US Environmental Protection Agency. The average daily doses (ADDs) of heavy metals received through ingestion, inhalation, and dermal contact for both adults and children were calculated. In this study, hazard quotient (HQ), hazard index (HI) and carcinogenic risk (RI) methods were used to estimate non-carcinogenic and carcinogenic effects of heavy metals. The HQ was calculated by subdividing ADD of a heavy metal to its reference dose (RfD) for the same exposure pathway(s). If the ADD exceeds the RfD, HQ>1, it is likely that there will be adverse health effects, whereas if the ADD is less than the RfD, HQ<1, it is considered that there will be no adverse health effects. A hazard index (HI), the sum of HQs, which means the total risk of non- carcinogenic element via three exposure pathways for single element of <1 indicates no adverse health effects, while HI values >1 show possible adverse health effects. Carcinogenic risk is regarded as the probability of an individual developing any type of cancer in the whole life time due to exposure to carcinogenic hazards and was calculated for As and Cd as follows:
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The value of SF represents the probability of developing cancer per unit exposure level of mg/kg day. The acceptable risk range for carcinogens is set to 10^-6 to by the USEPA, so that RI values below 10^-6 do not require further action, while risks greater than 10^-4 are considered to be of concern and require additional action to reduce the exposure and resulting risk.
Results and discussion
The soil pH ranges from 7.01 to 8.06, with an average value of 7.51 suggesting neutral conditions. Organic carbon (OC) contents of soil samples ranged from 0.06% to 4.91% (average 1.59%). In this study, based on the USDA textural triangle the main soil textures are loamy, clay loam and sandy loam, respectively.
The average abundance order of selected elements content is: Zn>Ni>Pb>Cr>Cu>As>Cd. Comparison of mean concentration of the potentially toxic elements in the soil samples with mean worldwide values reveals higher Zn, Pb and Ni contents in this area.
The results of contamination factor indicate very high contamination for Cd, Cu, Pb and Zn. Modified Degree of Contamination (mCd) calculated based on background values proves very high degrees of contamination for selected trace elements in Gasre Shirin and Eslamshahr landfills soil samples The results of enrichment factor evaluation similarity to contamination factor indicate that Cd, Cr, Pb, Cu and Zn have more influence from anthropogenic sources. The maximum EF of Pb, Zn and Cd and Cu is 346.7,124 and 51.9 respectively, which means very high enrichment in Ghasre Shirin landfill soil samples.
Exposure doses of 7 heavy metals in soil samples of un-enggenerd landfills for children and adults were calculated. The total exposure HQs calculated based on adults from ingestion, dermal contact, and inhalation for Cd, Cu, Ni, Zn, As and Pb was less than 1(except Ghasreshirin landfill). The hazard quotient values based on the adult risk for Cr were greater than 1.0. The results show that HQ for Pb and As in children by dermal and ingestion pathway is exceeded 1.0 in soil samples of Paveh, Javanrood, Ravansar, Kermanshah and Sangher landfills and Ghasreshirin and Eslamshahr landfills, respectively.
Conclusion
The concentration, pollution level, potential sources and health risk of potentially toxic elements in eight landfills top soil of Kermanshah province were investigated in this study. The following conclusions were drawn from this research.
- Compared with the background values of As, Cd, Cr, Cu, Ni, Pb and Zn in soils of Kermanshah Province, landfills soil have elevated metal concentrations as a whole.
- According to high contamination level and health risk of some studied potentially toxic elements, and also due to the proximity of contamination sources to residential district of the study area, more attention should be paid to manage and reduce contamination.
- These results provide basic information of toxic elements pollution control and environment management in the area../files/site1/files/121/Shakerii_Abstract.pdf

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Introduction
The problematic collapsible soils are deposits with wind origin that constitute about 10% of the total area of ​​the earth. Several countries, including China, Russia, the United States, France, Germany, New Zealand, and Argentina have vast areas of collapsible soils. These deposits usually form a semi-stable honeycomb structure and are highly susceptible to sudden changes in the volume reduction due to becoming humid. Collapsibility and other related issues such as different subsidences, land cracks and landfalls seriously damage the infrastructures constructed on these soils.
 By the growing rate of urbanization in different parts of the world, the probability of construction on these soils and consequently water availability for these soils will increase; as a result, humidity increases and the collapse of these soils may occur. Therefore, studying the behavior of these types of soils is very important. Over the past six decades, many researchers have studied the collapse mechanism of collapsible soils due to becoming humid. Discussions on this subject are summarized in three categories: traditional methods, soil structure studies, and soil mechanics-based methods. In the present work, collapsibility and its controlling factors in the soils of Kerman city are investigated.
 
Material and methods
To determine engineering properties of Kerman deposits in this research, the geotechnical information was gathered and 50 core samples were extracted from different parts of the city. The sampling points were selected such that they could have a high overlap. X-ray diffraction (XRD) was applied to determine the mineral type and soil structures while scanning electron microscopy (SEM) was used to study grain arrangement.
Results and discussion
Geotechnical characteristics of the samples collected from Kerman plain deposits include their physical and mechanical properties. Based on the obtained results, this fine-grained sediment generally includes two CL and CL-ML groups. The mineralogy studies of Kerman city soils show that the minerals in these deposits are mainly illite, chlorite, illite-smectite, calcite, quartz, and gypsum. In order to study the collapsibility level of the soils in Kerman through the field studies, samples were taken from different parts of the city and the tests were carried out to determine the physical properties, collapsibility index, and structural studies. Through the SEM analyses, samples related to Haft Bagh area, Motahhari Town, and Pedar Town revealed an open structure and intergranular pores and thus a high level of collapsibility. On the other hand, in the majority of samples taken from the central part of the city, such as Esteghlal Street, Azadi Square, Bahmaniyar Street, and Hafez Street, the soil aggregates generally have corner-to-corner connectivity, with no specific order in their structure, and the arrangement of the particles is random and irregular. The orientation of the particles mostly shows no sharp pattern. In addition to soil particles, they have shown random and disorientated cavities with small sizes, suggesting the density and compactness of the soil indicating a low to moderate collapsibility. In some areas (e.g., Pedar Township and Motahhari Township), crystalline salt and gypsum crystals are clearly seen. It is expected that by increasing the amount of water, these salts dissolve and their effects can be observed as dissolution cavities.
 The dissolution of soluble crystals can also reduce the strength of the soil structure and ultimately lead to soil degradation. Calcite crystals are also found in some places in the form of calcite cement among the grains, sometimes as single crystals, and sometimes as lime nodules within the soils of Kerman city. Among the stated criteria in this research, Denisov, Holtz, and Hill criteria, the Russian regulations and ASTM standards were employed to assess the potential of the studied soil collapsing. Based on the criterion of the construction regulations of Russia, it was found that the deposits of the city of Kerman are mainly collapsible (L>-0.1).                     
Moreover, based on the Denisov criterion (if e/eL>1.5 the soil is non-collapsible, if it is between 0.75 and 1.5, the soil is prone to collapsing, and if it is between 0.5 and 0.75, the soil is severely collapsible), soils of Kerman are within the range of collapse-prone soils. Finally, based on the ASTM criterion, in some areas of the city like Motahhari Town, Pedar Town, and Haft bagh, soils show a high collapsibility. In comparison, in the central parts of the city, the values of this criterion vary between 0.15 and 11, suggesting the presence of soils with a moderate collapsibility. Comparing the results obtained using these criteria it is seen that areas with a collapsible behavior are relatively similar collapsibility results are obtained.
Conclusion
Based on the achieved results, fine-grained sediments of Kerman city are mainly composed of CL and CL-ML groups. Mineralogy results indicate that the minerals in these deposits are mainly illite, chlorite, illite-smectite, calcite, quartz, and gypsum. SEM results for the central part of Kerman city confirm the compressed and densely compact form of soil particles. The results obtained, using the construction regulations of Russia show that the soils in the study area are collapsible. According to the Denisov criterion, they were found to be prone to collapse. Finally, based on the ASTM results for the central parts of the city, soils exhibit a low to moderate collapsibility. However, in some areas of the city, such as Motahhari and Haft bagh, soils show a complete collapsibility behavior../files/site1/files/131/1Extended_Abstract.pdf
 

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We collected soil samples at 23 sites from the petroleum contaminated soils (PC) in the west of Kermanshah province to investigate the sources and ecological risk of polycyclic aromatic hydrocarbons (PAHs). In this study, source apportionment has been carried out using Positive Matrix Factorization (PMF).The total PAHs concentration, have a mean value of 92.79 mg/kg, ranging from 7.37 to 609.67 mg/kg in PC soil samples. The average abundance order of different PAH ring compounds are 3 rings > 5+6 rings > 4 rings> 2 rings. The ecological risk assessment of PAHs revealed that all of the PAHs levels were higher contents than the effects range low (ERL) value and show higher concentrations than the ERM values, except for Pyr, Chr, BaA, BbF, BkF and BaP in the soil samples. The result of benzo (a) pyrene equation (BaP_eq) values indicates that the carcinogenic potency of PAHs should be given more attention due to the impending environmental risk in the study areas. Based on the PMF analysis four sources of PAHs are identified including coal combustion (21.48%), vehicular source (13.74%), unburned petroleum (20.84%) and creosotes (43.92%).Therefore, it was concluded that petroleum activities were major sources of PAHs in west of Kermanshah province.