Showing 224 results for Type of Study: Original Research
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 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 Mohammadreza Harirsaz, Dr Ali Ghanbari, Dr Gholamhosien Tavakoli Mehrjardi,
Volume 18, Issue 5 (12-2024)
Abstract
A series of reduced scale plate load tests was conducted to evaluate the bearing capacity of a strip footing resting on granular slopes. The effect of three factors including geocell burial depth, geocell length and spacing of geocell layers were discussed and evaluated. In this regard, 18 tests were performed to investigate the behavior of one and two layered geocell-reinforced slopes as well as the unreinforced slope and plain conditions. The results suggest that in single-layered geocell-reinforced slope, the optimum burial depth of the first layer of geocell reinforcement is 0.1 times of the strip footing width, whereas at greater depth beneficial effect of the geocell will reduce. In addition, expanding the reinforcement length up to approximately three times the foundation width could effectively increase the bearing capacity, whereas extending the length beyond that does not lead to any significant improvement. Furthermore, it was observed that use of two geocell layers by considering an optimum geocell space of 0.2 times of the foundation width could enhance the bearing capacity up to 226% in comparison with the unreinforced slope, and up to 79% of the plane condition for settlement ratio of 15%. Finally, the results indicate that the efficiency of the geocell reinforcements in lessening the gap between slope and plane conditions increases as the settlement of the footing rises due to better mobilization of dilation characteristics of granular backfill material and better lateral confinement of coarse aggregates in greater strains.
Dr. Ali Misaghi, Dr. Mohammd Raeesi,
Volume 18, Issue 5 (12-2024)
Abstract
In this study, we investigate the spatial distribution of landslides, strong motion data, and seismic intensity patterns associated with the June 20, 1990, earthquake, with a moment magnitude (Mw) of 7.4. Our primary objective is to elucidate the rupture status of the southeastern segment, Zard Geli, of the coseismic rupture by integrating geological and seismological data, Our findings indicate that the southeastern segment experienced only a partial rupture during the 1990 earthquake. This partial rupture is evidenced by the disproportionate distribution and density of landslides along the surface rupture. The incomplete rupture of this segment suggests that it retains a considerable amount of accumulated strain energy that was not fully released during the 1990 event. Consequently, this segment remains a potential source for future seismic activity. These findings have implications for seismic hazard assessment and risk mitigation in the region. This study highlights the need for continued monitoring and detailed geological and seismological investigations to better anticipate and mitigate the effects of future earthquakes.
Soroush Mahdavian, Navid Rashidi, Ali Raeesi, Jamal Abdullahi,
Volume 19, Issue 1 (6-2025)
Abstract
Clay soils typically have low strength and a high swelling percentage. They are considered as problematic soils in Civil Engineering projects. This research study examined the effects of magnesium chloride (MgCl2) solution on the clay soil improvement through conducting laboratory experiments. The experimental program included Atterberg limits, compaction, swelling, unconfined compression strength (UCS) and Scanning Electron Microscopy (SEM) tests. Available clay soil in the Lab was mixed with MgCl2 solution at weight percentages of 3%, 5%, 7% and 10% Samples for the swelling and strength tests were made using thestatic compaction method. The moisture and dry unit weight of the prepared samples were the same as those of thecorresponding compaction curves. The strength test results showed that the final strengths of the samples with 3% MgCl₂ at 7-, 14-, and 28-day curing times were 1401, 2018, and 1848 kPa, respectively. The results also showed that a reduction in strength of the samples occurred with more than a 3% solution of MgCl₂. For samples with 10% MgCl2 solution, the strength decreased until 14 days of curing time, but increased thereafter. Additionally, the results indicated that the reduction in swelling percentage compared to natural soil was 4.95%, 3.98%, 2.8%, and 3.9% for samples with 3%, 5%, 7%, and 10% MgCl₂, respectively, showing that the reduction in swelling depends on the MgCl₂ percentage. Additionally, the SEM results showed that the improvement in the soil was due to chemical reactions between the soil and MgCl₂.
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.
Mrs Roya Masoumipour, Dr. Saeed Mahdavi,
Volume 19, Issue 1 (6-2025)
Abstract
The Chador-Malu open-pit mine is faces complex challenges regarding the long-term stability of its slopes. These are directly influenced by time, environmental changes, and stresses induced by mining activities. Considering the existing evidence of potential future instability, displacement changes along the northern to eastern pit walls were analyzed over an 18-month period. Long-term wall displacements were measured using radar. Through back-analysis and three-dimensional numerical simulations, the equivalent creep behavior of the slopes was evaluated using the Maxwell creep model. After assessing the geomechanical parameters, the impact of three scenarios passage of time, bench widening, and pit deepening on slope stability was investigated under three horizontal-to-vertical stress ratios of 0.5, 1, and 1.5. The analysis results indicated that a horizontal-to-vertical stress ratio of 1.5 better matched the field observations. In the first scenario, a 50% increase in time led to over a 100% increase in displacement rates, indicating a rise in instability potential over time. In the second scenario, unloading the first two benches reduces the instability potential, due to an 18% reduction in uplift while unloading up to the eighth bench increased instability potential due to the reduction of weight at the slide’s toe and an increase in the average uplift. In the third scenario, pit deepening formed another sliding zone between the tenth and seventeenth benches.
Ehsan Pegah,
Volume 19, Issue 1 (6-2025)
Abstract
Accurately quantifying the anisotropic elastic parameters of in situ soils is essential for many geotechnical and geological engineering studies. This research introduces an innovative geophysical field technique for assessing these parameters in situ by utilizing the directional variations of P-wave and S-wave velocities. Assuming cross-anisotropy in the soil layers at the test location, it was shown that P- and S-wave propagation velocities along different orientations and planes can be effectively measured through a combination of seismic refraction and downhole surveys. The refraction data were analyzed using Seismic Refraction Tomography (SRT), Multichannel Analysis of Surface Rayleigh Waves (MASW), and Multichannel Analysis of Love Waves (MALW) to estimate the horizontal P-wave velocity (VPH), vertical S-wave velocity (VSV), and horizontal S-wave velocity (VSH), respectively.Moreover, the vertical and oblique P-wave velocities (VPV and VPθ) were identified by evaluating the travel times and distances of wave signals obtained from downhole tests. These velocity measurements were then incorporated into advanced equations formulated from elastic wave propagation theory, facilitating the computation of elastic parameters at the site. To evaluate the accuracy and efficiency of the proposed approach, the obtained results were compared with corresponding laboratory measurements, revealing a satisfactory level of agreement between the two datasets. The proposed methodology offers a practical means for in situ assessment of cross-anisotropic elastic properties in near-surface geomaterials using field-based seismic techniques.
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.
Tahereh Azari,
Volume 19, Issue 1 (6-2025)
Abstract
Accurately determining hydraulic parameter values is the first step in sustainably developing an aquifer. Since Theis (1935) introduced the type curve matching technique (TCMT), it has been used to estimate aquifer parameters from pumping test data. However, the TCMT is subject to graphical error. To eliminate this error, a multi-layer perceptron (MLP) artificial neural network (ANN) was developed as an alternative to the conventional TCMT. This MLP ANN models the Bourdet-Gringaten well function to determine fractured double porosity aquifer parameters. The MLP model was developed using a four-step protocol and trained using the backpropagation method and the Levenberg-Marquardt optimization algorithm for the well function of double-porosity aquifers. Through a trial-and-error procedure and by applying principal component analysis (PCA) to the training input data, the optimal network structure with the topology [3×6×3] is determined. We evaluated the validity of the developed network with synthetic and real field data. The network receives pumping test data and provides the user with aquifer parameter values. This network provides an automatic, fast procedure for determining double-porosity aquifer parameters, eliminating the graphical errors inherent in the conventional TCMT.
Mohammad Reza Haddad Tehrani, Mehdi Talkhablou, Mohammad Reza Asef, Mehdi Ostad Hasan,
Volume 19, Issue 2 (10-2025)
Abstract
Complex carbonate reservoirs, such as the Asmari Formation, present challenges to the accurate determination of geomechanical parameters and effective stresses due to high lithological and structural heterogeneity. The objective of this study is to develop a comprehensive three-dimensional model of geomechanical parameters and effective stresses in the Kupal oil field. Well log, core, and seismic data were used, and three-dimensional modeling was performed using the Sequential Gaussian Simulation (SGS) method based on variogram analysis. The prevailing stress regime was validated using FMI logs and wellbore breakout analysis. Additionally, a one-at-a-time sensitivity analysis was conducted on key parameters, including static Young’s modulus, Poisson’s ratio, cohesion, internal friction angle, and pore pressure. Results indicate that the maximum vertical effective stress (σv) is 87 MPa and the maximum horizontal effective stress (σHmax) is 127 MPa. Analysis of wellbore imaging data confirms a normal faulting stress regime (σv>σHmax>σhmin) in the field. Stress concentration around minor faults was also identified. The model was validated against one-dimensional models achieving 88% agreement. The findings of this study can be applied to well design, gas injection, and reservoir stability assessment in the Kupal field.
Kamal Ganjalipour, Majid Naeimi, Effat Zamani,
Volume 19, Issue 2 (10-2025)
Abstract
Exploratory studies and pumping tests are considered fundamental tools for understanding the hydrogeological behavior of aquifers. They play a critical role in water resources modeling, planning, and governing water resources. This article aims to analyze the role of these studies within the water governance framework in Iran by examining the institutional, technical, and legal challenges in comparison with developed countries. The findings indicate that weak legal requirements, the absence of an integrated data acquisition system, limited equipment, and a shortage of exploratory wells have led to reduced accuracy in baseline studies, weakened numerical models, and unstable decision-making. Additionally, the paper reviews the historical development of exploratory drilling and pumping tests, along with their tools and objectives, emphasizing the role of exploratory wells in developing conceptual models and monitoring aquifer dynamics under declining water table conditions. In conclusion, the article highlights the need to revise policymaking, strengthen institutional structures, and mandate the implementation of precise tests to achieve evidence-based water governance.
Dr Reza Toushmalani,
Volume 19, Issue 2 (10-2025)
Abstract
Inversion of magnetic data to characterisegeological structures, such as dikes, is a fundamental challenge in engineering geophysics due to its highly non-linear and ill-posed nature, necessitating robust optimization methods. This study introduces and evaluates for the first time, the Mountain Gazelle Optimizer (MGO) for the first time, examining its efficiency and potential as an effective solution to this problem. The MGOalgorithm is designed to find the global optimum by intelligently balancing exploration and exploitation within the parameter space. The performance of the MGO was assessed by comparing it with two distinct approaches: a powerful machine learning algorithm called Random Forest (RF), and a classic processing-estimation method based on Reduction to the Pole (RTP). Evaluations were conducted on synthetic data (with noise levels ranging from 0% to 20%) as well as on real field data from the Gansu iron deposit in China. The results clearly demonstrated the superiority of MGO in all scenarios. Not only did the algorithm exhibit greater stability against noise than RF, it also, achieved a Root Mean Square Error (RMSE) of 0.48 in the real data case study,, which was significantly lower than the error achieved by the classic method (0.88). Furthermore, the parameters estimated by MGO showed better alignment with the geological information from existing drilling data in the area. This study suggests that MGO's superiority obtained from its direct and global inversion approach. Ultimately, MGO is presented as an accurate and reliable tool for exploration and engineering applications.
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 Seyed Ali Asghari Pari,
Volume 19, Issue 6 (12-2025)
Abstract
Various factors influence earth dams' stability and flow rate, including geometric characteristics, material permeability, and upstream water height. Understanding unsaturated soil behavior in earth dams is crucial, necessitating the application of unsaturated soil mechanics principles due to the complexities involved. This study investigates the effect of Soil-Water Characteristic Curve (SWCC) parameters on the slope stability of an earth dam under steady-state and rapid drawdown conditions. The findings reveal that SWCC parameters significantly influence water flow and slope stability. Additionally, considering unsaturated unit weight can improve slope stability under varying conditions.
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.
