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Mahnaz Firuzi , Mohammadhosen Ghobadi , Ali Noorzad, Ali Asghar Sepahi,
Volume 15, Issue 1 (Spring 2021 2021)
Volume 15, Issue 1 (Spring 2021 2021)
Abstract
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
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 LI: area density, AL: area of landslides in each lithological unit, AT: area of landslides in total area.
where LF: frequency of landslide, NL: number of landslides in each lithological unit, NT: 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
Mohammad Hossein Keyghobadi, Adel Asakereh, Behzad Kalantari, Masoud Dehghani,
Volume 15, Issue 1 (Spring 2021 2021)
Volume 15, Issue 1 (Spring 2021 2021)
Abstract
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 (hrs) 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 (hrs/D=0.5) can decrease the bearing capacity. Even in some cases of reinforced base (hrs/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 (hrs) 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
Zahra Hoseinzadeh, Ebrahim Asghari-Kaljahi, Hadiseh Mansouri,
Volume 15, Issue 2 (9-2021)
Volume 15, Issue 2 (9-2021)
Abstract
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
Alireza Sadeghabadi, Ali Noorzad, Amiali Zad,
Volume 15, Issue 2 (9-2021)
Volume 15, Issue 2 (9-2021)
Abstract
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
Mr. Mohammad Alizadeh Mansouri, Dr. Rouzbeh Dabiri,
Volume 16, Issue 1 (5-2022)
Volume 16, Issue 1 (5-2022)
Abstract
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.
Dr. Seyed Hossein Hosseini Lavassani, Mr. Hamed Alizadeh, Pro. Ali Massumi,
Volume 16, Issue 1 (5-2022)
Volume 16, Issue 1 (5-2022)
Abstract
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.
Ali Kamali, Dr Mehdi Mokhberi, Dr Abbas Ghalandarzade,
Volume 16, Issue 2 (Summer 2022 2022)
Volume 16, Issue 2 (Summer 2022 2022)
Abstract
Marls are one of the problematic soils that undergo more erosion due to their deformability and sensitivity to humidity and weather conditions. The effects of these soils have been observed on subgrades of pavements, abutment of dams, foundation of high-rise structures, the interaction of soil-structure and etc. The strength and deformation of marls are more effective to moisture content. In addition, the dynamic parameters of theses soil are considerable as well as static geotechnical specifications. Soil dynamic parameters can be obtained from both laboratory experiments and field experiments. With the aim of understanding the dynamic behavior of marl soils, this study was carried out to evaluate the marls of northwest region of Shiraz City which is mixture of marls containing the expansive anhydride gypsum. For this purpose, the laboratory cyclic triaxial test and in situ downhole test has been performed. The results showed that for normal consolidated marls, with increasing the confined pressure from 400 to 600 kPa (increasing soil depth), the shear modulus increases from 50 to 200 kPa. In addition, the behavior of the damping ratio is relatively different for strains less than and greater than 1%, but in general, for strains higher than 1%, the damping ratio decreases from 0.21 to 0.18 with the increase confined pressure from 100 to 600 kPa.
Aylar Hosniyeh, Dr Rouzbeh Dabiri, Alireza Alizadeh Majdi, Elnaz Sabbagh,
Volume 16, Issue 4 (Winter 2022)
Volume 16, Issue 4 (Winter 2022)
Abstract
Silty soils containing sodium content, known as salty silty soils, are classified as another type of problematic soil. When this type of soil comes into contact with water, it can swell and diverge, leading to settlement and deformation. Considering that a significant part of the Urmia Lake basin and the Tabriz plain consists of sodium-rich fine soils, the aim of the project is to improve the quality of the soils. Therefore, one of the main objectives of this study is to assess the sediments within the lake bed in order to reduce erosion and to evaluate the possibility of improving and stabilizing the sodium saline silty soils in the area using the geopolymerization technique. To achieve this, pumice material with pozzolanic properties was separately mixed with the soil under investigation at weight percentages of 3%, 5% and 7%, together with a calcium hydroxide solution as a catalyst at concentrations of 2%, 5% and 7%. The samples were then cured for one day. Laboratory tests, including compaction, uniaxial compressive strength, direct shear, and consolidation, were carried out to evaluate the geotechnical behavior of the improved soil. The results obtained indicate that the combination of 3% pumice with 2% calcium hydroxide increased the uniaxial compressive strength of the stabilized sample by 1.32 times after one day of curing. In addition, the mixture of 7% pumice with 2% calcium hydroxide significantly improved the internal friction angle by 20 times. Finally, the combination of 7% pumice with 2% calcium hydroxide reduced the value of free swelling potential by up to 86%.
Khadijeh Kord, Heeva Elmizadeh, Hakimeh Amanipour,
Volume 17, Issue 1 (Spring 2023 2023)
Volume 17, Issue 1 (Spring 2023 2023)
Abstract
The study area is a part of the Dez River Basin, which is located in the central part of the basin. In this area, due to the climatic conditions, the irregular availability in terms of time and space, the increasing use of water resources and surface water resources, there is a great dependence on the underground water of the region. The main objective of this research is to investigate the factors influencing the fluctuations of the water level in the Dezful-Andimeshk plain during a statistical period of 20 years. For this purpose, using piezometric well level data and well logs of the study area in WinLog software, maps of the groundwater level and the bottom level of reservoir were prepared using theIDW method. The results of the research showed that the greatest drawdown occurred in north-eastern, south-eastern and western parts of the study area. Asthe amount of precipitation, evaporation and temperature are high in this part, one of the reasons for the decline in these parts can be attributed to the climatic factors of the region. Other factors in the decline of the reservoir level are the main river channel and the high slope of the area. Comparing the changes in the reservoir level with the flow of the Dez River showed that there is a high correlation between the changes in these two parameters with a time interval of one year. Therefore, according to agricultural activities, these limited resources should be harvested, scientifically and fundamentally, the region will be at risk of a serious water crisis in the future.
- Fatemeh Khalooei, - Heeva Elmizadeh,
Volume 17, Issue 2 (Summer 2023)
Volume 17, Issue 2 (Summer 2023)
Abstract
In this study, images from the Sentile 2 satellite have been used. In the study, the proximity of the images was taken into account to minimize the error due to changes in gray scale. Also in this study, GIS and remote sensing data and SNAP software were used as tools.According to the subsidence zones obtained in the study area, it is observed that the maximum amount of subsidence around the tomb of Sheikh Mohammad is between 80-90 mm per year of landslide. The results show that the highest rate of subsidence in the study area is due to agricultural use and irrigated agriculture in the region. This problem may be mainly related to the issue of groundwater extraction for agriculture and drinking, and possibly other factors such as geology and tectonics. The centralization of the maximum rate of subsidence in residential areas has led to relatively insecure living conditions for the inhabitants and increased their vulnerability to land hazards. Also, considering the results of the steps taken to study the phenomenon of land subsidence in the study area, it is concluded that the phenomenon of land subsidence has a significant relationship with the grain size and with the lowering of the water table. Therefore, the combination of radar interference methods with high spatial resolution with high spatial resolution, satellite positioning systems with high temporal satellite positioning systems with high temporal resolution, and precise alignment with very high accuracy, is a good way of to study the movement of the earth's surface.
Hossein Mohammadzadeh, Vahid Naseri Hesar, Hamid Ghalibaf Mohammadabadi,
Volume 17, Issue 4 (Winter 2023)
Volume 17, Issue 4 (Winter 2023)
Abstract
Due to the complex hydrogeology of karst areas, the sealing of dams in such areas is more difficult, time-consuming and expensive, and the possibility of water leaksge is higher. After the dewatering of the Gharetikan dam and appearance of downstream springs and the leakage of water from the abutment of the Tirgan limestone formation, the possibility of karst development is considered to be the most important problem of this dam. In this article, the potential of karst development in the area and supports of the Gharetikan Dam has been studied by carrying out geological studies, structural geology and joint studies, geotechnical permeability and analysis hierarchy method (AHP).. The results show that about 14.6% of the Gharetikan dam area has a high potential for karst development. The area of Gharetikan dam area is affected by the Sarroud fault zone system, which has caused the collapse of the left side of the dam axis. The joint studies in the abutment of Gharetikan dam show three main types of joints. Two groups of joints are located at the intersection with the dam axis and the slope of the other group of joints is towards the dam basin. The investigating of Lugeon permeability tests in the dam construction shows that the highest permeability can be seen in the left abutment with turbulent flow, and then under the river bed with linear and turbulent flow, but there is no permeability in the right abutment. And the flow is mostly linear. According to the structural-conceptual model prepared from the location of the Gharetikan dam, to the location of the dam axis in the Sarroud fault system, and the amount opening and the slope direction of the joints in each station, it is expected that the amount of water leakage and escape and the possibility of karst development from the left side and the bed of the dam will be more than the right side of the dam.
Hossein Ebrahimi, Farzad Akbari, Soroor Mazrae Asl, Babak Biglari,
Volume 17, Issue 4 (Winter 2023)
Volume 17, Issue 4 (Winter 2023)
Abstract
The Vorskharan karst spring with a catchment area of 50 square kilometers and an average discharge of about 1.35 m2/s is one of the most important springs in the city of Firouzkouh. In order to asses the hydrogeological and hydrogeochemical charachteristics of the spring, the physical and chemical properties of the spring water were measured and analyzed for several months. The results showed that the recession curve of the spring has a slope and the value of its coefficient is about 0.003. The low coefficienof the discharge variation t, electrical conductivity and major ions, as well as the single slope of the spring’s recession curve , are mainly due to the elongated shape of the aquifer and the long-term presence of snow in the catchment basin of the spring. Considering the relatively high water level of the spring and the existence of a sinkhole and a polje in the spring’s catchment area, as well as the coefficient of small changes in the physical and chemical parameters of the spring, it can be said that the dominant flow system in the aquifer which recharges Vorskharan spring,is conduit-diffusive. According to the field studies and the evaluation of the percentage of soil cover, the development of dissolved spaces and other morphological effects of karst, the percentage of annual recharge in the catchment area was estimated at 56%. With the amount of precipitation, the percentage of annual recharge, the annual recharge volume of the preliminary water catchment basin equal to 19.2 MCM and the annual discharge volume of the spring through the annual hydrograph of the spring was calculated to be equal to 20.1 MCM. It was also observed that the type of water is Ca-HCO3, and the lithology of the aquifer is calcareous and dolomite.
Miss Sooror Mazraeasl, Mr Farzad Akbari, Ms Elahe Iraniasl, Miss Leila Hosseini Shafei,
Volume 18, Issue 1 (Spring 2024)
Volume 18, Issue 1 (Spring 2024)
Abstract
Groundwater is one of the main sources of water supply for agriculture, drinking and industry in Iran, especially in areas with arid and semi-arid climates. Therefore, due to the high importance of groundwater resources, it is necessary to know the hydrodynamic parameters in order to determine the natural flow of water and manage the optimal utilization of groundwater resources. Considering the role of the Daloon-Meydavood aquifer in providing part of the water needed in the study area, especially for agricultural purposes, the hydrodynamic parameters of this aquifer were estimated using the methods of grain size analysis, geophysics and pumping test. The parameters were calculated by all three methods and validated using the flow rate of the exploitation wells. In all three methods, the hydrodynamic parameters (Hydraulic conductivity, Specific yeild, transmissivity coefficient) are the highest in the north and northeast and the lowest in the south and northwest. The results showed that 2 methods including grain size analysisand pumping test had the most similarity with the discharge map of the exploitationwells.
Dr Mehran Esfahanizadeha, Dr Mohamad Davoodi, Dr Ebrahim Haghshenas, Dr Mohamad Kazem Jafari,
Volume 18, Issue 2 (Summer 2024)
Volume 18, Issue 2 (Summer 2024)
Abstract
The determination ofgeological subsurface strata and shear wave velocity profiles is one of the most important engineering measures for seismic design and site effects studies. Recently, the use of seismic geophysical methods in engineering geological studies for this purpose has become widespread. In this paper, the accuracy and efficiency of seismic geophysical methods with active and passive seismic source in determining the subsurface geological structure of a selected site in the city of Abasabad in northern Iran have been studied. To this end, first, by conducting several exploratory boreholes, the subsurface geological structure of the study site up to a depth of 70 meters was carefully determined using engineering geological experiments. The results of this section showed that the shallow sediments of Abasabad site are mainly composed of sandy soils with four separate geological layers. In the next step, in two other separate boreholes, seismic geophysical experiments with active source of down-hole test were performed in order to accurately determine the shear wave velocity profile in different layers. In addition, in the next phase, using the array microtremor recording method, which is a new seismic geophysical method of passive-source type, to determine the subsurface geological structure of the study site in the form of shear wave velocity profiles. It should be noted that the array microtremor recording was performed using fifteen different arrangements of receptors (with different numbers and distances of receptors) and by two analyzing methods including F-K and SPAC. The results of these studies showed that both active and passive seismic geophysical methods had acceptable performance in determining the subsurface geological stratification of the site. It also could be inferred that the down-hole test with high accuracy determines the shear wave velocity in each layer compared to the array microtremor method but requires artificial production of seismic waves and borehole drilling. Array microtremor method without the need for drilling and production of artificial seismic waves has high efficiency in determining the subsurface layering and estimating the shear wave velocity of each layer and in general the results of this paper showed that in estimating the shear wave velocity compared to down-hole method shows up to 10% error.
Dr Sasan Motaghed, Dr Marzieh Shamsizadeh, Dr Nasrolla Eftekhari,
Volume 18, Issue 3 (Autumn 2024)
Volume 18, Issue 3 (Autumn 2024)
Abstract
In this study, we present the Seismic Hazard Possibility Space (SHPS) for the city of Ahvaz. To achieve this, we applied the intuitionistic fuzzy method to weigh the logic tree used in the hazard analysis and constructed the SHPS based on expert opinions regarding the degrees of membership and non-membership. Hazard disaggregation was performed by through the concept of intuitionistic fuzzy sets, leading to the development of an intuitionistic fuzzy of an Intuitionistic Fuzzy Logic Tree (IFLT). The SHPS includes both the degree of membership and non-membership for pathways contributing to hazard generation. The SHPS illustrates the acceptance, non-acceptance, and ambiguity associated with potential hazard values from an expert perspective, thus assisting analysts in selecting appropriate hazard values. According to the numerical results of our analysis in the Ahvaz region, the seismic hazard is located in an uncertainty (unacceptability) zone, indicating that experts have low confidence in the results of the probabilistic seismic hazard analysis (PSHA) for Ahvaz. In addition, the hazard is characterized by an "unconfident zone". This finding indicates that experts are fairly confident in the results of the analysis for Ahvaz. This finding implies that the models and parameters used in the PSHA for this region are not accepted by experts, and further efforts are needed to identify or develop appropriate models and accurate parameters specific to the area. In conclusion, this research demonstrates how intuitionistic fuzzy sets can be used to construct SHPS, providing a novel framework for quantifying uncertainty and expert opinion in hazard assessment.
Mr. Farhad Mollaei, Dr. Reza Mohebian, Dr. Ali Moradzadeh,
Volume 18, Issue 3 (Autumn 2024)
Volume 18, Issue 3 (Autumn 2024)
Abstract
The brittlenessindex is one of the most important parameters in geomechanical analysis and modeling. Many methods have been proposed to estimate the brittleness index. One of the recently used methods is the intelligent method. In this paper, firstly the aim is to introduce a new algorithm using deep learning algorithms to predict the brittleness index in one of the wells of the hydrocarbon field in southwest Iran. In this article, first, the effective features for the input of the algorithms were determined using Pearson's correlation coefficient, and then using (recurrent neural network + multi-layer perceptron neural network) (LSTM + MLP) and (convolutional neural network + recurrent neural network) (CNN+ LSTM) brittleness index was estimated and the mean error value (MSE) and coefficient of determination (R2) were calculated for the training and test data. For both training and test data, both algorithms have a coefficient of determination close to 1 and a very low error. Also, in order to ensure the results of the algorithms, a part of the data was set aside as blind data, and the error and coefficient of determination were calculated for this data, and the error was
Dr Eisa Hajiradkouchak, Dr Behzad Rahnama, Dr Hasan Nasrollahzadeh, Mr Ali Shahbazi, Mr Reza Raeiji, Mr Kazem Babaei,
Volume 18, Issue 3 (Autumn 2024)
Volume 18, Issue 3 (Autumn 2024)
Abstract
Many researchers believe that providing safe water, sanitary disposal and optimal management are the three axes of health, and in all these cases, while paying attention to the process of doing work, continuous control should also be done. This study was designed and implemented with the aim of seasonally investigating the physicochemical and microbial water quality of Qarasu River in Golestan province using the IRWQIsc index. 6 sampling stations were identified for Qarasu River and sampling was done once every month in four seasons of 1400. The measured parameters include pH, BOD, COD, dissolved oxygen (DO), electrical conductivity (EC), ammonium (NH4), nitrate (NO3), phosphate (PO4), total hardness (TH), turbidity and total suspended solids. It was a stool form. According to the measured parameters, Iran's surface water quality index IRWQISC was calculated. The results of the study based on the index showed that the quality of this index for all stations in all seasons was between 70.5 and 14.7 and according to the IRWQISC index, it was in five good categories (70-1.85), relatively good. (55-1/70), relatively bad (30-44-9), bad (15-29-9) and very bad (less than 15). The influencing parameters were total suspended solids, turbidity, nitrate, temperature and fecal coliform. It can be concluded that the amount of 70.5 with good quality is related to (Tuskestan village) in winter and the amount of 7.14 with very bad quality is related to (Pol Qara Tepe) in summer that the quality of the river water in The Gorgan to Aqqla road bridge station (Qorban Abad) is in bad condition in all seasons due to the entry of urban and industrial pollutants into this station, and Tuskestan village station has good and relatively good quality in most seasons because Tuskestan is in It is located in high altitudeand the entrance of clean running water into thisarea is more and it is far from industrial and urban pollutants.
Akbar Khodavirdizadeh, Hassan Moomivand,
Volume 18, Issue 4 (Winter 2024)
Volume 18, Issue 4 (Winter 2024)
Abstract
In this study, the stability of the Gougerd landslide of Khoy was investigated with respect to changes in the soil internal friction angle. Statistical analysis of the results of changes in the FS of different methods in analyzing the stability of the Gougerd landslide in 282 analyses showed that: 1) In static conditions, under the influence of groundwater conditions, the results of the stability analysis of various methods showed up to 35.2% changes in the FS, and the largest differences in the FS values were obtained in the conventional Fellenius, Spencer, and Morgenstern-Price methods. 2) In static conditions, the FS of various methods showed changes of up to 35% with respect to the effect of the internal friction angle, and the largest difference in the FS values compared to other methods was obtained in the conventional Fellenius method and the Spencer method. 3) In pseudo-static conditions and in the dry state, up to 5% changes in the FS were obtained in different analysis methods, and under the influence of groundwater conditions, the changes in the FS were up to 39.9%. The largest changes in the FS of the dry state were obtained in the simplified Janbu method, Spencer and Morgenstern-Price methods, and under the influence of groundwater, the largest changes in the FS were obtained in the conventional Fellenius method and Spencer method. In examining the results of this research, the effect of different conditions of groundwater level, soil internal friction angle, and earthquake force on the analytical mechanism of the relationships existing in various methods is recognized as the main cause of the difference in the results of different stability analysis methods.
Mr. Masoud Esmaeilzadeh, Mr. Ebrahim Keshavarz, Mr. Mohammad Golkhandandan,
Volume 18, Issue 4 (Winter 2024)
Volume 18, Issue 4 (Winter 2024)
Abstract
Estimating tunnel construction costs is one of the critical steps in project management. Several factors influence the total cost of a tunnel project, and the complexity and uncertainty in identifying these factors often lead to inaccurate cost estimates. Various analytical methods have been developed to estimate tunnel construction costs, but all have drawbacks. Utilizing real data from other projects can mitigate these shortcomings. In this research, we first discuss the growth of the tunneling industry and its impact on the development of economic infrastructure. We then review the historical research on tunnel cost estimation and the methodologies that have been developed in this area. The lack of a pricing schedule for tunnel construction in Iran, unlike in developed countries, results in inaccurate cost estimates for tunnel projects. This study examines both definite and probabilistic methods for estimating the cost of mechanized tunneling, based on the price schedule of "Dam Field 1403." We compare the cost of tunneling in Iran with other countries. The results indicate a 30% difference in the ratio of labor costs to the total project cost and a 92% difference in the cost per meter for mechanized tunnels in Iran compared to other countries. This discrepancy discourages private contractors from engaging in tunnel projects in Iran. Therefore, we propose the development of a comprehensive pricing schedule for tunneling to enhance the accuracy of cost estimation for tunnel projects in Iran.
Nazila Dadashzadeh, Morteza Hashemi, Ebrahim Asghari-Kaljahi, Akbar Ghazi-Fard,
Volume 19, Issue 1 (Spring 2025)
Volume 19, Issue 1 (Spring 2025)
Abstract
The urban development of Tabriz faces numerous geological and engineering challenges due to the presence of Neogene argillaceous-marly rocks. These rocks exhibit low mechanical strength and bearing capacity, as well as high deformability. This study aims to analyze these rocks and establish practical correlations among their petrographic, physical, and mechanical properties, alongside ultrasonic test results. These correlationscan help estimate uniaxial compressive strength (UCS), compression wave velocity (Vp), and elastic modulus (E). The findings indicate that argillaceous-marly samples, classified as very weak to weak rocks or hard soils with significant deformability, exhibit low compression and shear wave velocities. These samples are predominantly found in yellow, olive green, gray to dark gray, and brown colors throughout the city. The study reveals significant linear relationships between physical properties, mineralogical composition, UCS, and E with seismic wave velocity. Notably, there is a strong correlation exists between compression wave velocity and uniaxial compressive strength, shear strength parameters, cement content, and mineralogical composition in these rocks. These relationships suggest that mineralogy, porosity, density, and slake durability index are key factors influencing seismic wave velocity. Additionally, the variations in textural and microstructural diversity of argillaceous-marly-marly samples contribute to unpredictable mechanical behavior, which can pose potential hazards. Furthermore, a qualitative fissure index (IQ) was developed usingthe P-wave velocity of the samples to classify them into categories of high fissurability.
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