Journal of Engineering Geology

The Elastic Anisotropy Ratios in Cohesionless Soils and Corresponding Bilateral Correlations

Ehsan Pegah

The ratios of elastic anisotropy in cohesionless soils are always of substantial importance in respective analyses to the geotechnical and geological engineering projects. These ratios are raising from the available discrepancies in anisotropic elastic parameters ascribed to the different directions and planes of soil mass. The major objective of this study is to recognize the variations range of anisotropy ratios resulting from anisotropic shear and Young’s moduli for a variety of cohesionless soils followed by assessing the potential relations among these two anisotropies. To this end, by assuming the transversely isotropy in cohesionless soils, the anisotropic elastic constants from 266 conducted laboratory tests on 37 various soil specimens relating to 10 different sands were derived from conventional triaxial and seismic waves laboratory tests coupled with the numerical testing results in literature. By sorting the collected data and subsequently their analyses, at the first stage, the values of shear and Young’s moduli anisotropy ratios were calculated for the studied soils. Furthermore, by plotting the anisotropy ratios in several joint panels and performing a series of regression analyses on the resulting values, the possible dependencies were inspected between these two anisotropies. At last, the indicative equations among shear and Young’s moduli anisotropies were developed with insistence on use of which instead of the former similar relations in literature.

Monitoring the Subsidence of Kazerun Plain Using SENTINEL Images and Radar Interferometric Technique (DInSAR)

heeva elmizadeh

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.

Investigating the effect of weathering on the durability and deterioration of historical stone monuments in the south of Zanjan province

Davood Fereidooni

In this research, the durability and deterioration of two historical stone monuments, including the Dashkasan rock temple and the historical stone inscriptions of the Sojas cemetery in the south of Zanjan province, were investigated. For this purpose, two stone block samples were selected from each historical work for laboratory study. Based on the geological investigations, the historical monuments of the Dashkasan rock temple were carved on tuffs of the Karaj Formation. According to the thin section study, the Dashkasan temple rocks composed of the crystal vitric tuff and lithic vitric tuff and the samples of the historical inscriptions of the Sojas cemetery were limestone and very fine-grained sandstone, quartz being the dominant mineral of these rocks. In terms of physical characteristics, the samples studied have medium density and porosity. In terms of durability and deterioration, all four samples were subjected to 15 cycles of the slake durability test in normal water and sodium sulphate solution. The degradation function model and half-life of all four samples were determined and analysed. The results show that all four samples have a lower slake-durability index in sodium sulphate solution than in normal water. Due to the presence of quartz in lime or clay matrix, the samples of historical stone inscriptions from Sojas cemetery have more water absorption and porosity and are more durable, and their half-life is lower than the samples from Dashkasan rock temple.

Evaluation of the videogrammetry method for calculating the volume of earthworks in comparison with the conventional methods of land surveying

Asghar Milan

Calculating the volume of earthworks in mines is one of the challenging, costly, and time-consuming issues in the field. In mining projects, it is necessary to calculate the volume of excavation to estimate the volume of extraction in order to plan the sale of the produced products and to calculate the cost performance of the contractors. The calculation of excavation volumes presents many challenges, such as the selection of the best measurement tool and technique, the need to adjust maps produced in different time periods, the existence of inflation coefficients and the volume to weight conversion factor. Today, tools such as laser scanners, total stations and metric cameras are used to calculate earthwork volumes. However, they are expensive to use and require an experienced operator. Therefore, there is a need to investigate methods to calculate volumes in less time with acceptable accuracy. This research evaluated the use of smartphones for optimal volume estimation of earthworks. In this research, the image data obtained from the smartphone was processed with a technique based on structure from motion (SFM) and the results were used to create a digital terrain model to estimate the volume of earthworks. The calculated volume differences for the earthworks volume compared to ground methods for a soil mass and the studied excavation are 3.86% and 1.84% respectively, which shows that the method used in this research has the necessary accuracy to calculate earthworks volumes and considering the many advantages it has over traditional methods in terms of cost and time, it can replace them.

Prediction of Chloride in Groundwater Using Supervised Artificial Intelligence Committee Machine (SAICM) (Case Study: Sari Plain)

Fatemeh Kardel

Qualitative assessment of coastal waters affected by seawater salinity can be done using the parameter of chloride in groundwater. This research proposes a supervised artificial intelligence committee machine (SAICM) method for accurate prediction of chloride concentration in groundwater of Sari plain. SAICM predicts chloride concentration as the output of the model by non-linear combination of artificial intelligence models. In this research, Principal Component Analysis (PCA) method was used to identify effective hydrochemical parameters related to chloride concentration as input components to artificial intelligence models. Based on the results of PCA, parameters (Na, K, EC, TDS, SAR) were selected as input components of artificial intelligence models. Firstly, four artificial intelligence models, Sogno fuzzy logic, Mamdani fuzzy logic, Larsen fuzzy logic and artificial neural network were designed to predict chloride concentration. Based on the modelling results, all the models showed a good fit with the chloride data in Sari Plain. Then, the combined SAICM model was built, which combines the prediction results of 4 separate AI models using the nonlinear ANN combiner and determines the chloride concentration more accurately. The results show that the proposed SAICM can estimate chloride concentration with much higher accuracy than individual methods.

Dynamic systems modeling of consecutive multi-purpose reservoir dam by using Vensim software

somayeh zarei doudeji

The science of system dynamics is a management tool capable of simulating complex systems in water resources. In this research, the model of the dynamic system of multi-purpose consecutive Kardeneh-Sana dams located in Bushehr province has been simulated. The purpose of this modeling is to realize the different needs of the dam (drinking, environment and industrial agriculture) before its construction and also to investigate the effect of construction of the upstream dam on the supply of the downstream dam. The results were studied after calculating the annual and monthly percentage of volume and time supply of the different needs and source of supply, as well as considering two drinking water wells to provide drinking water in the months when the dam is not able to provide drinking water and the maximum The discharge of the current drinking water pipeline of the region was carried out. Six management scenarios were considered for modeling, and finally the sixth scenario was considered as the most optimal scenario. In order to evaluate the model, the simulated values were compared with the observed values of the water volume of Sana Dam. The results indicate that the volume supply of drinking, environment and industrial agriculture needs of Kardeneh Dam is 97.66, 96.59 and 82.76 respectively, and also the volume supply of environment and agriculture needs from Sana Dam is 100, 48 respectively. It is 83.0%, which is within the acceptable range of the Ministry of Energy. Based on this research, it was determined that by modeling based on model evaluation indicators including percentage of volume supply and percentage of time supply of different needs, it is easy to determine the effect of management and exploitation policies on the way of determining and allocating resources. Water observed and made the most optimal decision.