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Evaluating Groundwater vulnerability in Ghazvin Plain

Volume 1, Issue 3 (3-2004)
Abstract
(Paper pages 255-270) The groundwater protection is important in order to have a good management of water resources. The Ghazvin plain situated in west of Tehran, Iran has a critical situation in which the groundwater level declines and aquifer pollution has been observed in recent years. In this research, for evaluating the groundwater vulnerability, DRASTIC index has been used for this plain. Then, a Geographic Information System (GIS), ILWIS has been used to create a groundwater vulnerability map. The results of this study estimated DRASTIC value to be in the range of 35-108 using general DRASTIC value, almost 11% of the study area was recognized to have low feasibility, 43% moderate and 37% high and 10% very high feasibility for pollution. The DRASTIC results show a good adaptation between increasing the nitrate rate and the DRASTIC index
A New Approach to Evaluate Seismic Stability of Asphaltic Core Rockfill Dams
Ali Ghanbari, Mohsen Mojezi, Meysam Fadaee,
Volume 6, Issue 2 (4-2013)
Abstract
Construction of asphaltic core dams is a relatively novel method especially in Iran. Iran is located in a region with high seismicity risk. Therefore, many researchers have focused on the behavior of such types of dams under earthquake loading. In this research, the behavior of asphaltic core rockfill dams (ACRD) has been studied under earthquake loading using nonlinear dynamic analysis method and a new method is presented to assess seismic stability of these types of dams in earthquake conditions. Based on nonlinear dynamic analysis, the current study attempts to provide an appropriate criterion for predicting the behavior of earth and rockfill dams considering real behavior of materials together with actual records of earthquake loading. In this method, the maximum acceleration of the earthquake record (PGA) increases until instability conditions. Finally, a new criterion is presented for evaluating seismic safety of ACRDs via demonstrating curves of the crest's permanent settlement and maximum shear strain against maximum earthquake acceleration. Results of the proposed criteria can assist designers of asphaltic core dams to predict dam stability during earthquake event
The effect of the effect of adding ethylene-vinyl acetate (EVA) on soil resistance parameters
, , Morteza Jiriaei Sharahi,
Volume 15, Issue 4 (3-2022)
Abstract
Soil stabilization and reinforcement has long played an important role in civil engineering, especially in geotechnics, and over time and the need for a more robust and stable ground to withstand gravity and higher shear forces, has become particularly important. Also, in recent years, with the entry of the environment into the construction industry, with the aim of reducing the adverse effects of industrial waste and construction waste on people's living environment and preserving the environment for the future, in many cases reduces the economic costs of projects. In this research, granular soil is reinforced in two loose and semi-dense states using a waste material called ethylene-vinyl acetate (EVA). The experiments were performed without adding moisture, by weight percentage method and using CBR device. The results show that soil resistance increases significantly with the use of these additives and its effect on soil increases with decreasing soil specific gravity. Also, the optimal amount of additives in loose and semi-dense state is 2% additive and 1% additive, respectively.


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Investigating the effective parameters on the stability system of tunnels using the Rock Engineering System (RES) method
Mehdi Talkhablou, Seyed Mahmoud Fatemi Aghda, Habibulah Heidari Renani,
Volume 16, Issue 2 (9-2022)
Abstract
The stabilization of underground spaces is one of the most challenging topics in engineering geology. There are several methods to determine the type of tunnel stabilization system, but most of these methods have several weaknesses. Therefore, the development of a method that comprehensively considers almost all parameters influencing tunnel stability and their interdependencies has not received sufficient attention. The aim of this research is to investigate the parameters influencing the stability of tunnels using the rock mechanics system method. In this paper, 6 tunnels with different geological characteristics were selected. The effective parameters on the primary stabilization of these tunnels were coded using the ESQ method. Subsequent analyses were performed using the RES rock engineering system method to estimate and evaluate the optimal tunnel stabilization system. The results showed that parameters such as weathering of the joint surface, backfill and joint spacing played a more effective role than other parameters. For comparison, the analyses were also carried out using the RMR rock mass ranking method. The comparison between the results of the RES and RMR methods showed that the results of the RES method are in better agreement with the actual tunnel conditions and the shotcrete thickness of the proposed stabilization system of the studied tunnels. Since there is no limit to the number of input parameters in this method and, on the other hand, the mutual influence of the parameters on each other is considered, the relationships obtained from the RES method in this research can be effectively used in engineering projects along with other methods.
 

Investigating the groundwater quality of Evan Plain aquifer in Khuzestan province with emphasis on nitrate concentration
Dr Seyed Yahya Mirzaee, Phd Student Zahra Chaghazardi, Dr Manouchehr Chitsazan, Dr Farshad Alijani,
Volume 17, Issue 1 (3-2023)
Abstract
The Evan plain is located in the Khuzestan province in the southwest of Andimshek city. Groundwater is one of the available water resources for irrigation, drinking, and industry in this region. Due to the importance of examining the ground water quality of the Evan plain, hydrochemical parameters and nitrate pollution have been evaluated. Nitrate is one of the most widespread pollutants of ground water in the world. However, few studies have been conducted on this pollutant in the Evan plain. Therefore, to assess the quality of ground water in this area with emphasis on nitrate pollution, sampling was carried out in September of the water year (1400-1401) from 22 wells in this plain. During the sampling, field parameters (temperature, pH, EC), concentrations of major elements (Ca2+, Mg2+, Na+, K+, Cl-, SO42-, HCO32-, CO32-), and nitrate were measured. The results of the factor analysis demonstrated three influencing factors, namely EC, Na+, K+, Mg2+, Ca2+, Cl-, SO42-  (as the first factor), pH and Hco32- (as the second factor), and NO3- (as the third factor), with a total of 89.72% having the most changes in the Evan plain aquifer. The dominant water type in the Evan plain is sulfate-calcite. Hierarchical clustering analysis shows the three clusters for the regionalization of nitrate data. In general, the changes in nitrate ion concentration in the groundwater of the Evan plain are affected by the size of the soil particles, the depth of the groundwater, and the utilization of chemical fertilizers in the area.
 

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