Journal of Engineering Geology

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(Paper pages 255-270) The groundwater protection is important in order to have a good management of water resources. The Ghazvin plain situated in west of Tehran, Iran has a critical situation in which the groundwater level declines and aquifer pollution has been observed in recent years. In this research, for evaluating the groundwater vulnerability, DRASTIC index has been used for this plain. Then, a Geographic Information System (GIS), ILWIS has been used to create a groundwater vulnerability map. The results of this study estimated DRASTIC value to be in the range of 35-108 using general DRASTIC value, almost 11% of the study area was recognized to have low feasibility, 43% moderate and 37% high and 10% very high feasibility for pollution. The DRASTIC results show a good adaptation between increasing the nitrate rate and the DRASTIC index

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Slake durability of rocks is an important engineering parameter for evaluating deterioration of rocks in chemical and physical agents that are related to mechanical properties of rock. The main purpose of this study is to assess the influence of the number of drying and wetting cycles under variable pH conditions and controls of mineralogical composition on durability. For this purpose, five different types of tuff were selected from different parts in north Qazvin city. The samples were subjected to multiple-cycle slake durability testing with different pH values solution. Also the slake durability tests in saturated condition on samples, petrographical analyses and basic physical - mechanical test were performed. In addition, to assess the influence of mineralogical composition on durability, the mineral contents of the original material and the material passing from the drum of the slake durability apparatus after fifteen cycles were also determined by XRD analyses. It was concluded that the slake durability of tuff is independent of the pH in acidic solution circumstances. Mineralogical composition, fabric and weathering rate are considered to have a greater influence on the slake durability of tuff. A strong relationship between the point load strength and the fifteenth-cycle slake durability index is found in the rock types studied.

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This paper has evaluated the groundwater quality index of Lenjanat aquifer. Water quality index as a unique index is presented to describe overall water quality conditions using multiple water quality variables. Physical and chemical data of 66 water samples were used in this study. The results have been obtained by Comparing the qualitative features with the World Health Organization (WHO) standard and Industrial Research of Iran (ISIRI) standards. In calculating GQI, 7 parameters, including calcium (Ca), magnesium (Mg), sodium (Na), chlorine (Cl), sulfate (SO4), total dissolved solids (TDS) and nitrate (NO3) have been used. Groundwater quality index shows the medium to relatively high groundwater quality in the study area. Minimum and maximum value of the index is calculated as respectively 55 and 93. Land use map shows that along the Zayanderood River and around the location of rice paddies, water quality reaches to the lowest quantity. Optimum index factor technique allows the selection of the best combination of parameters dictating the variability of groundwater quality.

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One way of reduction of leakage from beneath of earth dams is using of one contact clay layer with very low permeability and intermediate to high plastisity and connectig it to core of dam. Since, most of fine-grained soil in environtment of dam have low plastisity and preparing it from another place is not economic, use of bentonite in order to improvement of engineering characteristic of borrowed clay is suitable way.
In this search effect of bentonite on geotechnical properties of fine-grained soils with low plastisity are evaluated. Results of this research show that hydraulic conductivity, consolidation coefficient, dry density, colifornia bearing ratio (CBR),.....are decreased with increase in bentonite content but optimum moisture , Aterberg limits , cohession and so on are increased with bentonite addition. Finally, with analysis of obtained result, optimum percent of bentonite is offered in order to improve of engineering properties of used clay in contact region.

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In contrast with Mobility Factor (MF) and Risk Assessment Code (RAC) indices, I_R attributes a risk share to metal species bound to reducible and oxidizable phases which are totally neglected in both of the two above-mentioned indices. In other words, besides the absolutely mobile fractions, the potentially mobile ones are also regarded in risk evaluation process elaborated by I_R. The different structure of the newly-developed index may prevent risk level underestimation especially in case where a remarkable percent of bulk concentration is accumulated within reducible and oxidizable phases. The independency of the index value to the bulk concentration makes it possible to discuss the potential risk in different levels of bulk concentration. Furthermore, the index capability in indication of risky pollution, regardless of the pollution source type, may prevent the probable misleading caused by distinct separation of bulk concentration into geopogenic and anthropogenic portion

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This paper aims to present an experimental and numerical study on the effect of wetting-drying cycles and plasticity index on the California Bearing Ratio (CBR) of lime stabilized clayey soils. The numerical analysis was carried out based on finite element method for comparison between results of experimental and numerical studies. Three clays with different plasticity indices were mixed with various amounts of hydrated lime and compacted at optimum water content. The CBR tests were conducted to the soils and admixtures after specified curing time and various numbers of wetting-drying cycles. The experimental results indicate that addition of lime content up to 4% causes significant increase in the CBR values. Based on the obtained results the CBR decreases during the wetting phase and increases during the drying phase of each cycle. After 3 cycles the CBR values of lime stabilized clayey soils are increased. Also, for stabilized clays by increasing the plasticity index, the CBR values resulted by increase of lime content are decreased. The comparison between numerical and experimental analyses indicates a good agreement between results.

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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

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Durability is a significant parameter in engineering geology and it shows the extent of the degradability of rocks as the result of mechanical and chemical breakdowns. This phenomenon is closely linked to the composition, porosity and texture of rocks. To understand the relationship between the chemical composition of rocks and their durability the mineralogical properties of the rocks along with durability tests under both acidic and alkaline pH environments were determined. Five samples of limestone and three samples of marl were analyzed. The results revealed that rocks containing high levels of CaCo3 were affected in the acidic conditions while rocks containing high levels of SiO2 were not affected by variance in the pH of the environment. These second groups of rocks were more dependent on the texture of their constituent minerals.

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./files/site1/files/4Extended_Abstract.pdfExtended Abstract
(Paper pages 73-90)
Introduction
Up to now, various indexes and methods have been presented for evaluating the abrasivity of rocks. In total, these methods can be divided to two main groups; the methods based on nature of rocks, methods based on heuristic tools. Schimazek F-abrasivity index is one of the most powerful and applicable indexes for evaluating the rock abrasiveness. This index uses the grain size, Brazilian tensile strength and equivalent quartz content for abrasivity analysis. Since the values of these parameters are equal in Schimazek index, therefore, in some cases this index doesn't have suitable ability to distinguish and classify the rock abrasiveness. This paper tries to modify the Schimazek index considering the weights of its applied parameters.
Material and Methods
In this research, Fuzzy Delphi Analytical Hierarchy Process (FDAHP) has been used to calculate the weight of dominant parameters in rock abrasivity. For this purpose several questioners have been distributed and the expert opinions were collected. The results showed that the quartz content, grain size and tensile strength have the weight of 0.4, 0.31 and 0.29 respectively and new Schimazek F-abrasivity index is as presented in equation (1).
    
In the next stage, in order to facilitate the application of new index, a new classification system was developed. This classification and related weighing graphs (Figure 1) help to change the discontinuous classification to continuous one.
Results and discussions
In order to verify the application of the new developed index, ten ornamental stones have been studied and the old and modified Schimazek indexes were calculated for all of them. Then, the cutting rate (sawing rate) of each stone was recorded in laboratory and the mathematical relationships between new and old indexes have been achieved. The results show that the new Schimazek abrasivity index has higher ability to predict the cutting rate than old one (Figure 2). 

 
Figure1. Continuous weighting for parameters of Schimazek F-abrasivity index


Figure2. Regression of old and new Schimazek F-abrasivity index with cutting rate of granite ornamental stones
Conclusion
Generally it could be concluded that, the main weakness of Schimazek F-abrasivity index which is the equality of parameters’ importance, has been removed by idea developed and confirmed in this study. The different weights which allocated to grain size, Brazilian tensile strength and equivalent quartz content in study, improves the Schimazek index applicability in rock engineering applications specially rock cutting and drilling. Therefore, it is recommended to use new method instead of old one in future applications.
 




 

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In recent decades many researchers have studied on the damage assessment of structures after a seismic event. To assess the damage of structures under an earthquake, it is so important to study the correlations between earthquake parameters and damages of the structures. A lot of seismic parameters have been defined by researchers to characterize an earthquake. Spectral parameters of an earthquake convey a variety of information about ground motion, so they can properly characterize an earthquake. Also a lot of damage indices were proposed by researchers to quantify the damage of the structures or to rank their vulnerability relative to each other. Park-Ang index is one of the best indices to describe the damage of a structure. In this paper, the correlations between spectral parameters of earthquakes and Park-Ang indices are studied. Three RC frames with different height are analyzed under far-fault earthquake records by nonlinear dynamic analyses. The correlations between spectral parameters and Park-Ang indices of the frames are calculated. The results show that in all the frames most of spectral parameters have strong correlations with damage intensity. In order to estimate the damage potential of an earthquake, some spectral parameters which have high correlations with damage intensity can be proper indices. Housner intensity, acceleration spectrum intensity and velocity spectrum intensity are shown to have strong correlations with damage intensity. In this paper, a new spectral parameter which has high correlation with damage intensity is achieved. 

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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

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Introduction
Solid waste is one of the unavoidable products of every society that necessitates the establishment of municipal solid waste management system. Because of variability in quantity and composition of municipal solid wastes, several management scenarios are considered. Assessing the environmental impacts of the life cycle of these scenarios will have a significant role in reducing and resolving urban service management problems. The aim of this study was to compare different scenarios of municipal solid waste management in Sirjan city using life cycle assessment (LCA) approach. LCA methodology is used to evaluate the environmental performance of the waste management of Sirjan for different scenarios, according to the ISO standards 14040 series 2006.
Material and methods
After identifying the quantitative and qualitative characteristics of the produced wastes within the scope of the study, the quadratic steps of the LCA method are followed in relation to each of the scenarios. The stages of life cycle assessment in the present research are as follows:
 1. Determining goals and scope: Our goal is to compare environmental impacts of scenarios that include different methods of disposal. The boundaries of the study start from the collection of municipal solid wastes from the transfer station and ends with the final disposal of waste (Figure 1)

Figure 1. System boundary
Four scenarios have been investigated and evaluated in the environmental field (Table 1).
Table 1. Disposal solid waste scenarios

Scenario	Compost (%)	Recycle (%)	Incineration (%)	Landfill (%)
1 2 3 4	0 68.4 17.1 0	0 19.2 15 19.2	0 0 55.9 69.8	100 12.4 12 11

2. Collecting data and life cycle inventory (LCI): Various tools have been developed for LCI, one of which is the IWM-2 model. The IWM-2 model is one of the lifecycle assessment models that can be used to define different scenarios and then to compare the environmental impacts of each scenario. At this stage, the data from physical analysis, the amount of waste produced, the stages of separation at source, collection, transportation and final disposal, were collected and analyzed and the amount of contamination caused by each of the scenarios and energy consumption were determined.
3. Life cycle impacts assessment (LCIA): Assessing the impacts of the life cycle is a step of life cycle assessment, aimed at understanding and assessing the magnitude and significance of the potential environmental impacts of a product or service. At this step, the various information and data obtained at the LCI stage are reduced to less indicators and impact categories in order to facilitate the interpretation of this information and provide clearer outcomes to decision makers and managers. In this step, input data are allocated to the five impact categories of energy consumption, greenhouse gases, acid gases, photochemical gases and toxic emissions.
4. Interpretation of results: At this stage, the results of the LCI and LCIA will be evaluated so that the stages or points which have the greatest and least harmful impacts on the environment in the production and consumption of the product have been determined. Finally, conclusions and solutions are explained.
Results and discussion
Results of the model were allocated to five categories consisting of energy consumption, greenhouse gases, acid gases, photochemical gases and toxic emissions. In every category, the ecological index as a quantitative measure to compare scenarios was calculated.
Conclusion
In this study, the life cycle assessment approach was used as a decision tool for choosing the appropriate waste disposal scenario in Sirjan city. The second scenario (68.4% compost, 19.2% recycling, 12.4% landfill) was selected as the preferred option for municipal waste disposal in Sirjan city. Also the results of this study show that in an integrated municipal waste management system, increasing the rate of separation and recycling will significantly reduce the release of environmental pollutants../files/site1/files/142/5.pdf