Journal of Engineering Geology

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Introduction
Landslide is known as one of major natural hazards. Landslide susceptibility mapping is known as efficient approach to mitigate the future hazard and reduce the impact of landslide hazards. The main objective of this research is to apply GIS spatial decision making systems for landslide hazard mapping in the 5^th segment of Ardebil-Mianeh railroad. Evaluation of the landslide criteria mapping and their relevancy for landslide hazard can be also considered. To achieve the research objectives, an integrated approach of Fuzzy-Analytic Hierarchy Process (AHP), Fooler Hierarchical Triangle and Fuzzy logic methods were employed in GIS Environment.
Material and methods
Within this research, we also aimed to apply GIS spatial decision making systems and in particular GIS multi criteria decision analysis which are available in Arc GIS and Idrisi softwares. We have identified 8 casual factors (including: density of vegetation, land use, faults desistance, distance from rivers, distance from roads, slope, aspect, geology) based on literature review. Accordingly, these layers were prepared in GIS dataset by means of applying all GIS ready, editing and topology steps. The criterion weighting was established based F-AHP approach. The criteria weights was derived and rank of each criterion was obtained. Accordingly, the landslide susceptible zones were identified using GIS-MCDA approaches.
Results and discussion
Finally the functionality of each method was validated against known landslide locations. This step was applied to identify most efficient method for landslide mapping. According to the results and based on the values derived from Qs, P, and AUC, the accuracy of fuzzy method was accordingly about 0.33, 0.74 and 0.76, respectively. In context of Fuzz-AHP the accuracy of 1.08, 0.88 and 0.94 were obtained. While, the accuracy of Fooler Hierarchical Triangle were obtained 0.78, 0.84 and 0.91, accordingly.
Conclusion
As results indicated integration of Fuzzy-AHP represented more accurate results. Results of this research are great of important for future research in context of methodological issues for GIScience by means of identifying most efficient methods and techniques for variety of applications such landslide mapping, suitability assessment, site selection and in all for any GIS-MCDA application.

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Introduction
"Sulfide-carbonate" deposit is a term, which comprises a series of sulfide minerals such as Zn-Pb ore minerals, mainly considered as related to weathering of Zn-Pb sulfide concentrations and influence in sedimentary hosts (carbonate). There are more than 350 Zn-Pb deposits located in Iran, including world-class deposits such as Angouran, Mehdiabad and Irankouh. Due to the mining activity of these deposits, it creates a significant amount of mine waste that releases of these wastes in the environment causing severe problems. One of the main problems is the formation of Acid Mine Drainage (AMD). AMD is produced by oxidation of sulphide minerals, particularly pyrite (FeS2) in waste dump. Due to low pH and the ability to dissolve metals and other compounds, it can host a number of environmental problems. A phenomenon known as natural or alkaline mine drainage (NAMD) occurs at high pH values ​​when the neutralizing minerals are significantly present in the mine waste or when the oxidation of the sulfide minerals is poor. However, the metals and cationic species, such as Cu, Pb and Cd, are more soluble at low pH. In contrast, elements that form anionic species, such as Se, Cr, V, and Mo, tend to be more soluble at high pH and Ni, Zn, Co, As, and Sb, are soluble at near-neutral pH, and can potentially contaminate mine effluents, even without acidic conditions. Therefore Acid or Neutralization potential (AP&NP) of waste dump is significantly affects on the composition, transfers and fates of contaminations transmitted from waste dump. The aim of this study was to monitoring heavy metals concentrations and assessments of pollution potential of waste dumps in Anguran mine by static method and has been compared by mineralogical approach.
Material and methods
The Angouran Zn-Pb deposit is located in the 135 kilometers southwest part of Zanjan Province, NW Iran. This area belongs to the northwestern part of the Sanandaj-Sirjan Zone, a metamorphic belt related to the Zagros orogeny. Angouran mine is one of the most important carbonate hosted Zn-Pb deposits in Iran that mining activity has been created a significant amount of waste dump in around pit. To achieve the goals, the 47 samples taken from different surficial parts of the waste dump were analyzed by using the ICP-MS method to determine the concentration of elements and heavy metals. These elements and metals includes: Ca, Mg, S and As, Cd, Cr, Cu, Ni, Pb, Zn. The pollution index (PI) were modeled for heavy metal contamination risk zoning then modified Acid Base Accounting (ABA) static method was used to evaluate of acid and neutralization potential (AP&NP) of the waste dump samples and the results were modeled by Kriging method. At the end, mineralogical approach (Mg + Ca concentration) was used to determine the source of neutralization and to better interpret the static results.
Results and discussion
The results of contamination index showed that zinc, arsenic and cadmium had the highest average contamination index (18.89, 12.13 and 5.8, respectively) and the trend of total metal changes in the region as Zn> As> Cd> Pb > Ni> Cr> Cu was rated.
Datas measured in modified ABA method were modeled in 2D maps using the Kiriging method. Due to the low total sulfur content (less than 1%), all of the samples were Net Neutralization Potential (NNP) with a range of 49- 990 kg calcium carbonate per ton, and the study area was classified into three neutralization potential (NP), High (NP) and Very High (NP) levels. The mineralogical approach (Mg + Ca concentration) was used as a useful tool for better interpretation of modified ABA results and determines the neutralizing source. Mineralogical approach results indicate that calcite species are the main source of neutralization and have high correlation coefficient (R = 0.99) with the modified ABA method. In order to validate the results, the presence of mineral calcite was confirmed by XRD analysis on 4 samples.
Assessment of AP and NP of sulfide – carbonate waste dump in this research can be used as a basis model for other similar mines to control environmental problems and to identify the behavior and to transfer heavy metals in mine drainage in the future. Mineralogical approach results show that neutralizing potential and neutralizing source can be obtained without using expensive mineralogy analyses in this type of carbonate-sulfide deposit



 

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Introduction
Loess soil is one of the problematic soils that should be improved its geotechnical properties before the project is implemented. Lack of attention to this issue has caused in many problems for civil projects in Golestan province. This has been more evident in some of the rural areas built on this type of soil. Moreover there are many reports regarding different geological hazard such as subsidence, divergence, erosion and landslide in Golestan loess soil. Among the different types of loess soils found in Golestan province, silty loess should be given more attention due to their large extent and being the bed soil of many villages, and many reports of its hazards.
One of the methods for improving soil mechanical behavior and its geotechnical properties is to use additives to reduce geological hazards. Due to the fine-grained structure of loess soils, the application of nanoparticles is more efficient and could result in solving many of the related problems. Nanotechnology is new scientific field which affects many aspects of engineering and in recent years, many efforts have been made to use this new technology in various geotechnical branches.
So far, research has been carried out on the improvement of various soil types with additives such as cement, bitumen, ash, lime and various types of nanoparticles. Nowadays, the use of nanoparticle additives due to reduction of environmental pollution than other additives has a wider application in improving the physical and chemical properties of problematic soils.
In the present study, the effect of nano-kaolinite on strength properties including uniaxial compressive strength, elasticity modulus, cohesion, and internal friction angle of silty Loess in Kalaleh city of Golestan province have been investigated.
Material and methods
In order to carry out the present research, sample of the silty loess soil from Kaleh city of Golestan province was collected and prepared. Then, 0.5, 1, 1.5, 2, 3 and 4 weight percent of nano-kaolinite were added to soil samples. The soil samples were prepared in a natural state (without additives) and with the additive for uniaxial compressive strength and direct shear tests. Strength properties of soil specimens including uniaxial compressive strength, elastic modulus (based on uniaxial compressive strength test), cohesion and internal friction angle (based on direct shear testing) were determined for native soil and its mixture with different percentage of nano-kaolinite. The data were analyzed and the effect of nano-kaolinite on the strength properties of the silty loess soil sample was investigated.
Results and discussion
Uniaxial compressive strength and modulus of elasticity have been increased with increasing amount of nano-kaolinite, and after 2% nano-kaolinite, increase in nano-kaolinite did not have any significant effect on uniaxial compressive strength and modulus of elasticity. The uniaxial compressive strength and the modulus of soil elasticity in the natural state (without nano-kaolinite) are 1.12 and 15.89 kg/cm² respectively, and when 2% of the nano-kaolinite is added to the soil, the values ​​of these properties are maximal and reached to 1.19 and 18.10 kg/cm², respectively.
For native soil (without nano-kaolinite), the cohesion value is equal to 0.09 kg/cm², and with increasing nano-kaolinite from 0.5 to 2%, the cohesion shows an incremental trend and reached to 0.16 kg/cm². With increasing the additive percent from 2 to 4% the amount of cohesion were constant and equal to 0.16 kg/cm². The increasing of cohesion can be attributed to the fact that nanoparticles enhanced water absorption of soil particles which caused in better cohesion and also they affected chemical actions and surface electrical charge of soil particles.
Conclusion
The results of the uniaxial compressive strength tests show that adding up to 2 weight percent Nano-kaolinite to the dry soil increases the uniaxial compressive strength and modulus of elasticity of silty loess soil in the Golestan province, which can be due to proper locking between the nanoparticles and soil particles and increased cohesion.
The results of direct shear tests showed that adding up to 2% nano-kaolinite to dry soil increased the cohesion of the soil and consequently increased the shear strength of the soil.
On the other hand, adding the different amount of nano-kaolinite has not changed much in the internal friction angle of the silty loess soil in the Golestan province.
 
 

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Introduction
Landslides have an effective role in the destruction of freeways and railroads, which have been caused to many human and financial losses. Understanding this phenomenon and its effective factors can be important in planning for development projects and away from landslide prone areas. Based on extensive field in the Qazvin-Rasht freeway that the authors carried out in various researches in 2014-2017, it was found that the freeway was threatened by the type of instabilities due to variety of lithologies  and tectonic structures exploitation phase and needs to be stabilized. The purpose of this study is to determine of the distribution of landslides in different types of lithologicalunits of the Qazvin-Rasht freewaythat shows the role of geology and differences in geotechnical characteristics and tectonic structures in the creation and distribution of landslides on the road.The role of geology on the difference in geotechnical properties and tectonic structures in the creation and distribution in the road. Geological engineering properties and appropriate stabilization methods is the other goals of this study.
Material and Methods
In the study, the locations and the type of landslides are distinguished and the information were plotted on geological map. Then by the ARC GIS 10.2 program, and the use of area density method, the percentage of landslide events in each geological formation was identified. In order to study the role of lithology (type of rock, texture, mineralogy, weathering, alteration and erosion), sampling were carried out from rocks of Karaj formation, Shemshak formation, Cretaceous orbitalolina limestone and Fajan conglomerate. Geotechnical characteristics of the samples were determined by performing laboratory tests such as dry weight, porosity, uni-axial compressive strength according to ISRM standard (1979). For determining the role of tectonic structures (number of joints, dip and dip direction, length (m), spacing (cm), filling percentage, opening (mm), roughness, weathering, water, friction angle) were performed. Then, the results obtained from relative density and frequency were matched with the geological, geotechnical characteristics and tectonic structures of each formation.
Results
In order to separate different types of landslides on various kinds of rocks, area density and frequencyof  landslides were determined by Eqs 1 and 2. Graph of frequency and area density are presented in Fig. 6 and Table 2, respectively. As can be seen in this figure and table, in Karaj formation, the percentage of rock fall, toppling, avalanche, scree slope and combined slip are the highest. In the rocks belonging to the Shemshak formation, the susceptibility of the debris flow and landslides has been increased. In Fajan conglomerates and limestones of the Ziarat and Cretaceous formations, the rockfalls is more formed.
where L_I: area density, A_L:  area of landslides in each lithological unit, A_T: area of landslides in total area.
where L_F: frequency of landslide, N_L:  number of landslides in each lithological unit, N_T: number of landslides in total area.
Conclusion
Result showed that despite significant heterogeneity in lithology, geotechnics, engineering geology and tectonic structures, there are similarities between the types and distribution of landslides. Four of the identified landslides consist of rock fall, toppling, avalanche in the resistant and medium strength rocks such as andesite, trachy-andesite and basalts of Karaj formation, Cretaceous orbitalolina limestone and Fajan conglomerate with regard to the dominant direction of the joints in relation to the slope, the shear strength of the joints and their weathering, falling and scree slope in thesiliceous zone and composite landslide in the argilite-alounite zone due to the high alteration and groundwater level and water retention by the presence of clay minerals, landslide in the sequence of loose and resistant rocks, debris flow and landslides in the soils of Shemshak formation due to the lepidoblastic texture of the slate and their high erosion potential due to the weather climate along the Manjil-Rudbar freeway../files/site1/files/151/4.pdf

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Introduction
The ring footings are very important and sensitive due to widespread use in various industries such as oil and gas; so finding some ways for improving the behavior of these types of footings can be very valuable. One of these ways, which is very affordable and also can be help in environmental protection, is the use of granulated rubber that made from disposable materials like scrape tires, as the soil reinforcement. In the present study, the behavior of ring footings with outer constant diameter of 300 mm and variable inner diameters (90, 120 and 150 mm with inner to outer diameter ratio of 0.3, 0.4 and 0.5) placed on unreinforced sand bed and also granulated rubber reinforced bed, has been investigated by field test. The effects of important parameters like inner to outer diameter ratio of ring footing and thickness of rubber-soil mixture on the behavior of ring footing in terms of bearing capacity, settlement and inside vertical stresses of footing bed have been studied and the optimum values mentioned parameters have been determined.
Material and methods
In all tests, a sandy soil was used to fill the test trench which was excavated in the natural bed of the earth with a length and width of 2000 mm and a height of 990 mm. It should be noted that the type of this soil is well-graded sand (SW) according to the Unified Classification System (ASTM D 2487-11). This sand had medium grain size, D₅₀, of 2.35 mm, moisture content of 5.4% and friction angle of 41.7^∘. The granulated rubber particles with dimensions between 2-20 mm, a mean particle size, D₅₀, of 14 mm and a specific gravity, Gs, of 1.15, have been used in all tests for using in rubber-soil mixture layer.
The loading system consists of several parts such as loading frame for providing reaction force, hydraulic jack, load cell, load transfer system (including loading shaft which was located below Load cell and footing cap which was located under the loading shaft) and rigid steel loading plates with different inner to outer diameter ratios (d/D=0.3, 0.4 and 0.5 and constant outer diameter of 300 mm). Some devices like load cell, LVDT, pressure cell, data logger and unit control were applied to collect the data and control the system. Both soil and rubber-soil mixture layers were compacted by vibrating plate compactor to gain their maximum densities. After preparing the tests, the static load was applied on the system at a rate of 1 kPa per second until 1000 kPa or until backfill failure.
Results and discussion
The results of tests on both unreinforced and rubber reinforced beds indicated that the ring footing with inner to outer diameter ratio (d/D) of 0.4 had the maximum bearing capacity in all settlement levels. This behavior can be related to the arching phenomenon within the internal spaces of ring footing with optimum inner to outer diameter ratio. In fact, when the ring footing with optimum inner to outer diameter ratio is subjected to a certain level of loading, the soil inside the ring seems to be compacted due to interface effect of the two sides of the ring. However, by increasing the inner to outer diameter ratio more than its optimum value, the ring behaves like two independent strip footings without any interface effect and therefore the bearing capacity decreases.
The results of tests showed that the vertical inside stresses in different depths of footing bed (both unreinforced and rubber reinforced beds) decrease with increasing d/D ratio. This stress reduction process can be due to the transfer of stress concentration from the points close to the center of the ring to the outer point because of turning from the ring mode with interface effect to the two independent strip footings that mentioned earlier.
The results of rubber reinforced cases illustrated that, regardless of the footing settlement level and also irrespective of d/D ratio, the bearing capacity of ring footing increases with increasing the thickness of rubber-soil mixture layer (h_rs) up to the value equals 0.5 times the outer diameter of ring footing and further increase in this thickness more than mentioned optimum value (h_rs/D=0.5) can decrease the bearing capacity. Even in some cases of reinforced base (h_rs/D=1), the bearing capacity can be reduced to the value less than that of unreinforced cases. It can be due to high compressibility of rubber reinforced layers with higher thicknesses than optimum value.
It should be mentioned that the rubber reinforced layer can reduce the vertical inside stresses compared to unreinforced cases. It can be due to this fact that the rubber reinforced layer acts as a wide slab. Such that it can spread the applied loading over a wider area. Also rubber reinforced layer has high capacity of absorbing energy and therefore can decrease the vertical inside stresses.
Conclusion
In the present study the behavior of ring footing placed on rubber reinforced bed have been investigated by field test. The effect of different parameters such as inner to outer diameter ratio of ring footing and the thickness of rubber-soil mixture layer on the bearing capacity, settlement and vertical inside stresses of the footing bed were studied. The result indicates that:
- In both unreinforced and rubber reinforced bed, the ring footing with inner to outer diameter ratio (d/D) of 0.4 had the maximum bearing capacity, regardless of settlement level.
-The vertical inside stresses in different depths of footing bed decrease with increasing d/D ratio.
-The bearing capacity of ring footing increases with increasing the thickness of rubber-soil mixture layer (h_rs) up to the optimum value equals 0.5 times the outer diameter of ring footing.
-The vertical stresses can be reduced by using rubber reinforced layer../files/site1/files/151/5.pdf
 

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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../files/site1/files/152/%D8%AD%D8%B3%DB%8C%D9%86_%D8%B2%D8%A7%D8%AF%D9%87.pdf

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Expansive soils contain clay minerals such as compacted kaolin which are widespread in nature. Displacements of this type of soils are associated with matric suction and degree of saturation. To determine the in-situ characteristics, necessary measures may be required to deal with the possible failure related to this type of soil. Different constitutive models of unsaturated soils have been considered the subject of many recent researchers (Sheng et al. 2004; Wheeler et al. 2003; Nuth and Laloui 2008; Zhang and Lytton 2009 a, b 2012). However, those constitutive models are generally complicated that are not properly implemented in computer programs for practical applications. The Barcelona Basic Model (BBM) is one of the geomechanical constitutive models to capture the elastoplastic behavior of unsaturated soils../files/site1/files/152/%D8%B5%D8%A7%D8%AF%D9%82_%D8%A2%D8%A8%D8%A7%D8%AF%DB%8C.pdf

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In this study, it is attempted to analyze sensitivity and reliability in order to evaluate the liquefaction potential in soil layers in Tabriz. 62 boreholes that had possible conditions for liquefaction were selected. Seismic mapping was simulated using finite fault method and then the effect of soil layers on PGA was estimated. In continue, the liquefaction potential index was estimated and the zoning map of liquefaction risk was presented. In final, through sensitivity and reliability analysis of the Monte Carlo method, the rate of density function against safety factor of the soil layers versus to liquefaction was determined.

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Many researches have been currently conducted on the effects of fault distance on structures revealing that their seismic response can differ according to their distance from the fault. Suspension bridges due to their long period and high flexibility can be more sensitive to this phenomenon, especially in vertical vibration. Since the engineers tend to use longer spans, the length factor should be studied more accurately. In this paper, the effects of length factor on the seismic response of the suspension bridge under near and far-fault ground motions were addressed. The Vincent Thomas and Golden Gate suspension bridges as short and long ones, respectively, are selected as the case studies. The seismic responses of two bridges under five main worldwide ground motions contained both near and far-fault ones, with the same peak ground’s acceleration, are evaluated. The results indicated that the response of both bridges to the near and far-fault ground motions are perfectly different. Short span suspension bridges are vulnerable to near-fault ground motions, whereas long span ones are completely susceptible to both near and far-fault ground motions, and by increasing the length of span, the sensitivity of bridge was increased against far-fault low frequency excitations. Also, maximum displacement responses of spans in both bridges did not increase by maximizing peak ground’s acceleration.

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