Mister Hamzeh Torkamanitombeki, The Doctor Mashalah Khamehchiyan, Mistress Maryam Nazari, Mister Shazdi Safari,
Volume 17, Issue 3 (12-2023)
Abstract
The purpose of the research is to investigate the risk of liquefaction risk at the beaches of Bustano in the western part of Bandar Abbas in Hormozgan province. The periodic stress method was used as the method to evaluate the liquefaction potential based on the data obtained from Standard Penetration Test (SPT). The acceleration of 0.35 g was chosen as the maximum acceleration of the bedrock, and cross sections were extracted using Rockwork software. From an engineering geological point of view, the characteristics of the sedimentary deposits and the collected geotechnical information were analyzed to generate geotechnical index profiles. As the study area is located at the edge of the folded Zagros, seismically it has the characteristics of the Zagros-Makran transition zone which basically exerts the most pressure on the saturated sediments of the area. Due to the strong movement of the earth in generating liquefaction, the seismic bedrock acceleration (PGA) and the maximum horizontal acceleration at the ground surface (amax) were evaluated by liquefaction analysis using LiqIT v.4.70 software. The results indicate that the sandy and silty sediments of the study area are the outcome of the weather changing processes at the northern altitudes of the region. Granular sand and silt sediments were found under favorable conditions with high groundwater level, confirming the presence of liquefaction phenomenon in the area. Zoning maps of the intensity of liquefaction were extracted at the surface and at depth were obtained in different parts of the Bustano, indicating the different classes of risk of liquefaction in the soil of this area. In general, the occurrence of liquefaction with high intensity liquefaction was predicted for the Bustano area.
Miss Faeze Majidi, Dr Mohammad Fathollahy, Engineer Habib Rahimi Menbar,
Volume 17, Issue 3 (12-2023)
Abstract
Aggregate is the main component of concrete and plays an essential role in the quality of concrete. Alkaline silicate reaction (ASR) is one of the most important reactions in concrete that can lead to concrete destruction. Aggregates containing active silica are responsible for this reaction, and the higher the amount, the greater the expected volume of reactions. The rate of increase of the reactions with changes in the amount of silica aggregates is part of the subject of this research. In this regard, a material was selected as the base material from the mountain quarry, and the necessary tests were performed on it by adding silica aggregates, 5, 10, 15, and 20 percent, the ASR test was performed on them according to the ASTM C1260 standard; The results showed that the expansion of the samples will increase by 0.01, 0.02, 0.04 and 0.06% respectively. Next, for the effect of microsilica on ASR, 5, 10, 15, and 20% were added to the materials and the results showed that microsilica reduced the expansion of the samples by 0.009, 0.014, 0.022, and 0.032 respectively and the increase of 20% of microsilica has reduced the expansion of the samples by 50%.
Hossein Mohammadzadeh, Vahid Naseri Hesar, Hamid Ghalibaf Mohammadabadi,
Volume 17, Issue 4 (12-2023)
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.
M.sc. Behrooz Margan, Dr. Davood Fereidooni,
Volume 18, Issue 1 (5-2024)
Abstract
In this research, various aspects of the rock burst phenomenon in the Haji-Abad tunnel site in the Hormozgan province have been discussed. Considering that the tunnel site is located in an active tectonized environment in terms of geological conditions and the depth of the tunnel in some parts reaches more than 100 to 253 m, and also considering the variety of rocks in the tunnel site, which are massive rocks with high strength up to broken fault zones, the importance of studying and investigating the phenomenon of rock burst is very important for the safety of the labor force and equipment and the stability of the underground space. For this purpose, the Haji-Abad tunnel site has been divided into ten units of engineering geological conditions using the BGD method, which includes eight units T1 to T8 and two crashed zones Tf1 and Tf2. Then, using common experimental and semi-experimental methods, the phenomenon of rock burst in the tunnel site has been evaluated. In the experimental procedure, Goel et al.'s criterion was used, according to which the rock burst phenomenon does not occur in any of the tunnel units. Using semi-empirical methods, including the criterion of linear elastic energy of the tunnel site units in the range of very low to moderate rock burst phenomena and using the tangential stress criterion, the site units in the medium to very high range and based on the stress criteria of these units in the moderate to high range and finally, using the fragility criterion, all site units are placed in the range of high rock burst.
Mohammad Zainali, Dr Mohammad Reza Asef, Dr Ruholah Nadri,
Volume 18, Issue 1 (5-2024)
Abstract
This paper investigates the application of geomechanical and geological engineering methods to determine the optimum working face width for the safe and efficient extraction of manganese ore extraction at the Venarch Mine (Qom Province, Central part of Iran). The underground workings on the west face (240m depth) present significant geotechnical challenges due to the presence of faults, clay seams, and loose rock layers. These features require careful careful stability analysis to ensure the safety and economic viability of the underground mining operation. This study uses three established methods for rock mass classification and stability assessment. The Rock Mass Rating (RMR) classification system, the Q-system (Barton), and the numerical analysis using Plaxis 3D software. A robust and data-driven approach to determining the optimum workshop width was achieved by employing a synergistic combination of these three methods, together with meticulous ground observations and expert engineering judgement. This framework offers a powerful tool for determining the optimal and safe workshop width for this sector of the mine. By capitalizing on the strengths of each methodology, this research aims to establish a data-driven and informed decision-making process to ensure a stable and economically viable approach.
Seyyed Mahmoud Fatemi Aghda, Seyyed Sara Mousavi Herati, Mehdi Talkhablo, Amir Maziar Raeis Ghasemi,
Volume 18, Issue 2 (9-2024)
Abstract
The alkali-silica reaction of aggregates is one of the most significant factors in the destruction of concrete structures worldwide. This is due to chemical reactions between alkaline fluids in concrete voids and active silica minerals present in some aggregates. Considering that many physical, chemical and mechanical properties of concrete are related to aggregates, the role of aggregates in concrete is crucial. This research aims to investigate the compatibility of aggregate petrographic studies and accelerated prismatic mortar testing in predicting the reactivity of aggregates and determining the intensity of aggregate reactivity using the DRI index (a semi-quantitative complementary petrographic analysis). The study was carried out on laboratory samples of aggregates from mines around Tehran, using the ASTM C295, ASTM C1260 and ASTM C856-4 tests. The results showed that pyroclastic aggregates, which include sandy tuff, crystalline tuff (dacitic andesite) and glassy tuff, have the potential to cause an alkali-silica reaction due to their glassy background and microcrystalline silica. During the alkaline reaction tests of the aggregates, evidence of gel was found in cracks, holes and cement paste. In addition, the DRI index showed that the fine aggregates of both study areas were in the "slightly damaged" category and the coarse aggregates were in the "severely damaged" category.
Dr Sasan Motaghed, Dr Marzieh Shamsizadeh, Dr Nasrolla Eftekhari,
Volume 18, Issue 3 (12-2024)
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.
Nafiseh Shokri, Dr Aliakbar Momeni,
Volume 18, Issue 4 (12-2024)
Abstract
The purpose of this study is to create a map of landslide hazard potential along the Tuskestan road using Analytical Hierarchy Process (AHP) model. The effective parameters on landslides that were used in this study are lithology, slope, slope aspect, vegetation, distance from the road, distance from the stream, and distance from the fault. At the first, a map of each of these parameters is prepared and divided into three or four subgroups based on their changes. Then, using hierarchical analysis, for each of these subgroups based on the degree of superiority , a weight was assigned to compare them together, so that qualitative maps are converted into quantitative maps. The result of this weighting showed that lithology and slope had the greatest effect, while the distance from the fault had the least effect in landslide hazard zoning. The final weight of each layer was obtained by multiplying the weight of each parameter by the weight of its sub-group. Finally, these quantitative maps were integrated into the Geographic Information System (GIS) environment to obtain the final landslide hazard zonation map. Assessment of the location of the previous landslides showed that among the 7 old landslides, 6 landslides were in the range of high hazard potential and 1 landslide was in the relatively high hazard category, which indicates the accuracy of the landslide hazard map. The obtained hazard zoning map showed that 9.3% of this area with an area of 355 hectares is located in the category of high hazard potential of landslides.
Akbar Khodavirdizadeh, Hassan Moomivand,
Volume 18, Issue 4 (12-2024)
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 (12-2024)
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.
Eng. Mohammad Ijani, Dr. Ebrahim Rahimi, Dr. Vahab Sarfarazi, Dr. Ali Faghih,
Volume 18, Issue 4 (12-2024)
Abstract
Numerical modeling is an essential tool in engineering analysis, particularly within the fields of geoscience and geotechnics. The PFC2D software stands out in this field, using the Distinct Element Method (DEM) to simulate processes related to engineering geology and geotechnical assessment. This study focuses on the analysis and comparison of two common contact models: the Flat Joint Model (FJM) and the Linear Parallel Bond Model (LPBM). The Unconfined Compressive Strength (UCS) test is chosen as a the benchmark for calibrating and validating the PFC models. Sandstone samples for this study are taken from the Aghajari Formation located on the southern limb of the Madar Anticline. The results show that both contact models have a high ability to simulate the UCS in the calibration process. As this test is primarily used to calibrate the failure point (σc) and Young's modulus, the output values for both models are almost identical. However, the post-failure behavior in the stress-strain curves differs between the models, with the FJM demonstrating a more brittle response compared to the LPBM. The ability of the FJM model to simulate rough surfaces and material discontinuities allows for the representation of tensile cracking.
Dr Mohammad Fathollahy, Engineer Habib Rahimi Menbar,
Volume 18, Issue 4 (12-2024)
Abstract
In order to produce strong and durable concrete, it is essential to accurately assess the alkali reactivity potential of aggregates. Alkali reactions occur gradually over time and are therefore often overlooked in the early stages of a project.. This research investigates the alkali-aggregate reaction (AAR) potential of concrete aggregates. Petrographic analysis of aggregates, based on ASTM C295, is a simple and rapid method for identifyingminerals that may react with the alkalis in cement. In this study, susceptible aggregates were identified through petrography, and then the accuracy of the results and the importance of petrographic analysis were verified using laboratory methods (ASTM C586 and ASTM C1260) to select suitable materials with minimal cost and time before designing the concrete mix. The results indicate that carbonate aggregates may contain silica and have alkali reactivity potential, necessitating the use of ASR testing methods as well. In addition, the results demonstrate that petrographic analysis is an effective and valuable method for identifying minerals with alkali reactivity potential.
Dr. Amin Jamshidi,
Volume 18, Issue 4 (12-2024)
Abstract
The durability of a building stone is its resistance to deterioration processes under the climatic conditions of a given geographical area. This parameter plays an important role in the selection of a suitable building stone, as ignoring it can lead to premature deterioration of the stone during the life of a building. Therefore, before selecting a building stone, it is necessary to pay special attention to its durability and to select a stone that has a suitable resistance to environmental degradation processes. The physical and strength characteristics are among the factors that influence the durability of a building stone. The evaluation of these characteristics can provide valuable information about the durability of stone subjected to deterioration processes. In this work, the effects of physical and strength characteristics on the durability of building stones were investigated. The results indicate that porosity, water content, degree of saturation and pore size distribution are the most important physical characteristics determining the durability of a building stone. In addition, strength properties, including uniaxial compressive strength, tensile strength, flexural strength and abrasion resistance, also play an important role in the durability of a building stone. The results of the present study can be used as a simple, quick, inexpensive and practical tool to indirectly evaluate the durability of building stone against environmental degradation processes.
Dr Emad Namavar,
Volume 18, Issue 5 (12-2024)
Abstract
A considerable part of Golestan Province is covered by loess soils, most of which are of the silty loess type, which is one of the most problematic soils. The proximity of the Caspian Sea leads to salinity of the groundwater in some areas of the province. Due to high evaporation, salts reach the surface and cause salinization of the silty loess soils at the surface. The presence of soluble salts can lead to changes in the engineering properties of silty loess soils at the site of construction projects. It is therefore necessary to investigate the influence of salts on the geotechnical properties of silty loess soils. The aim of this study was to investigate the effect of sodium chloride or halite (NaCl) and calcium sulphate or gypsum (CaSO4.2H2O) salts, as the two most abundant natural salts, on the engineering properties of silty loess soils. For this purpose, silty loess soil samples were collected from Maraveh Tappeh city, Golestan province, Iran. Geotechnical tests including uniaxial compressive strength, shear strength and standard compaction tests were then carried out on soil samples in the natural state and with 3, 5, 7, and 9% NaCl and CaSO4.2H2O. Based on these tests, the variation in optimum water content (ωopt), maximum dry density (ρdmax), uniaxial compressive strength (UCS), cohesion (C), internal friction angle (φ) were evaluated. The results showed that these parameters increased with increasing both natural salts concentration. Finally, the reason for the changes in the engineering properties of the soil samples due to the presence of these two natural salts was discussed.
Mr. Mehdi Abbasi, Prof. Gholamreza Lashkaripour, Prof. Naser Hafezi Moghaddas, Dr. Hossein Sadeghi,
Volume 19, Issue 1 (6-2025)
Abstract
The elastic modulus is considered one of the most essential parameters in the analysing and designing deep foundations and underground structures. Accurate determination of this parameter usually requires expensive and time-consuming in-situ testing, and validating its accuracy poses significant challenges. Therefore, researchers have consistently focused on developing empirical models based on geotechnical parameters. In the present study, multiple linear regression models, including general, coarse-grained soil, and fine-grained soil models, were developed to predict the elastic modulus using data obtained from 180 boreholes totaling 5,783 meters in the Mashhad Metro Line 3 project.. Out of 489 pressuremeter tests, 160 datasets were selected based on the availability of complete geotechnical parameters at the same depth. The analysis incorporated the influence of various parameters, including the percentage of sand, silt, and fine particles; grain size characteristics (D10, D30, D60, uniformity coefficient, and coefficient of curvature); Atterberg limits; moisture content; natural and dry density; specific gravity; and cementation indicators (gypsum, carbonate, and organic matter), as well as depth and in-situ stress. The final regression models were developed using a backward stepwise method, implemented through Python programming. The resulting regression equations were derived, and comparative plots between predicted and actual elastic modulus values were presented. The findings demonstrate that the proposed model offers reliable accuracy in estimating the elastic modulus. To evaluate the accuracy of the proposed models in predicting soil elastic modulus, an independent dataset of 39 pressuremeter test results, including both fine- and coarse-grained soils, was used. Statistical indicators demonstrated that the overall model performed best (R²=0.79, MAPE=9.86%). Additionally, the low values of normalized RMSE confirmed the stability and acceptable accuracy of all models.
Nazila Dadashzadeh, Morteza Hashemi, Ebrahim Asghari-Kaljahi, Akbar Ghazi-Fard,
Volume 19, Issue 1 (6-2025)
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.
Maedeh Roshan Liarajdameh, Milad Davari Sarem,
Volume 19, Issue 2 (10-2025)
Abstract
Iran, due to its location between two active tectonic plates, has always been exposed to numerous earthquakes. The occurrence of more than 100 severe earthquakes in the past century indicates the country’s high level of vulnerability to this natural hazard. The aim of this research is to analyze the seismicity and assess the earthquake hazard in Shahid Rajaei Port, as the largest commercial port in Iran (located at the intersection of the North-South transit corridor), which will be a fundamental step in enhancing the resilience and sustainability of the vital infrastructures in this region. In this study, all seismic events occurring within a 200-kilometer radius of the site were used, along with the Knopoff and Ez-Frisk software. The statistical analysis of historical and instrumental earthquakes indicates a high level of seismicity in the region, characterized by moderate-magnitude earthquakes with short return periods, such that earthquakes with magnitudes between four and five on the Richter scale constitute a larger share. The probabilistic hazard assessment estimated the maximum horizontal and vertical accelerations as 0.385 and 0.290 (g), respectively. Additionally, the site response spectrum was prepared based on the accelerographs of the Tabas earthquake and the isoacceleration maps of the study area, generated at intervals of 1.0 degrees in both latitude and longitude directions. The results showed that the study area has a seismic hazard of 0.85 (g), which is higher than the standard values specified in Iran’s Code 2800, placing it within the very high relative hazard zone. Therefore, implementing risk-based approaches in infrastructure development helps optimize port design and reduce earthquake-related damages.
Mojtaba Rahimi Shahid, Gholam Reza Lashkaripour, Naser Hafezi Moghaddas,
Volume 19, Issue 2 (10-2025)
Abstract
The Sanandaj–Sirjan Structural-Sedimentary Zone is one of the most important geological regions in Iran. The limestone formations in this area play a key role in civil engineering and mining projects. Knowing the precise mechanical properties of these rocks, especially the uniaxial compressive strength (UCS dry) and dry point load index (Is₅₀-dry), is essential for safely and economically designing structures. Because direct testing methods are costly and time-consuming, this study uses indirect modeling techniques, such as regression and neural networks, to predict these properties. First, a comprehensive database was compiled by collecting the physical, mechanical, dynamic, and chemical data of limestone samples from the region. Then, univariate, bivariate, and multivariate regression analyses were conducted to extract statistical relationships among the variables. Finally, multilayer perceptron neural network models with various architectures based on the Levenberg–Marquardt learning algorithm were developed. The comparison results of the model performance indicated that neural networks, due to their ability to identify complex and nonlinear relationships between parameters, provide more accurate predictions of the limestone mechanical properties compared to statistical models. A comparison of the correlation coefficients of multivariate regression equations and neural network models showed that, overall, using neural network models improves the accuracy of UCS Dry predictions by 14.89% and the Is ₅₀-Dry predictions by 4.70%. The results show that predicting UCS Dry in the presence of Is ₅₀-Dry among the input parameters has a significant impact on improving the accuracy of the models. For example, the model with the inputs Is ₅₀-Dry, SH, γ Dry and n showed very good performance. For predicting Is ₅₀-Dry, the models that included the parameters SDI1 and BI Dry as inputs also performed very well. The application of these models can contribute to cost reduction, increased speed of rock engineering studies, and improved safety in civil projects.
Dr. Amin Jamshidi,
Volume 19, Issue 2 (10-2025)
Abstract
Stones are widely used for building facades, flooring, paving, stairs, kerbs and load-bearing components. Weathering processes can have adverse effects on stones in terms of their aesthetic and technical properties. Changes in these properties will lead to the stone deterioration, resulting in financial damage to the building from both architectural and structural perspectives. Understanding the mechanisms by which weathering processes cause stone deterioration can be as a useful and efficient tool for assessing the long-term durability behavior of stone during its service life in a building. This study systematically investigated the mechanisms of the freezing-thawing and salt crystallization processes in the building stones deterioration. To this end, published papers on the deterioration of building stones, including igneous, sedimentary, and metamorphic, due to freezing-thawing and salt crystallization processes were collected. Discussions performed on the mechanisms of freezing-thawing and salt crystallization reported in these papers from various perspectives were compared. The findings indicate that in each of these processes, more than one mechanism involved in the deterioration of building stone. In addition, results showed that depending on factors related to the surrounding environment of the stone and on the other hand, the inherent properties of the stone, various mechanisms will have different adverse effects in the deterioration of building stone.
Dr Emad Namavar,
Volume 19, Issue 6 (12-2025)
Abstract
Accurate geotechnical classification is essential for excavation design in urban environments, where soil behavior is highly influenced by excavation-induced stresses. This study refines the geotechnical characterization of fine-grained alluvial deposits belonging to the youngest sedimentary unit (Unit D) in Rieben’s classification. A comprehensive investigation was conducted through borehole drilling, Standard Penetration Tests (SPT), pressuremeter testing, and laboratory experiments including triaxial, uniaxial, and direct shear tests. Excavation stability was assessed using the Morgenstern–Price method under both short-term and long-term conditions. Based on the geotechnical parameters and slope stability simulations, Unit D was subdivided into three distinct zones (D1, D2, and D3) with different excavation behaviors. Zone D1, characterized by lower sand content, allows deeper vertical cuts, whereas the presence of sandy lenses in Zone D3 restricts excavation depth and requires gentler slopes. The findings provide an updated geotechnical classification framework for fine-grained alluvia, offering practical guidelines for safe excavation design and contributing to the broader understanding of alluvial systems in urban geotechnical engineering.
The developed framework offers substantial practical advantages including cost reduction through minimized laboratory testing, rapid prediction capabilities for quality control, and enhanced risk assessment through uncertainty quantification. The integration of petrographic analysis with machine learning provides engineers and practitioners with a scientifically robust and economically viable approach to rock strength assessment, supporting more reliable engineering design and reducing the risk of costly project failures.
