Showing 68 results for kh
Dr. Davood Fereidooni, Dr. Sajeddin Mousavi, Dr. Esmaeil Najafi, Dr. Gholam Reza Khanlari,
Volume 16, Issue 4 (Winter 2022)
Abstract
Assessing and understanding the hydromorphological characteristics are necessary to understand the behavior of a river and its active processes. This is useful for understanding the erosion and sedimentation regime and changing the river path, for making correct engineering and human activities in the river's catchment area. The Gian River, with an average annual discharge of 2.3 m3/s, is one of the tributaries of the Gamasiab River in the Hamedan province. From a geological and hydrogeomorphological point of view, the Gian is a small river. It is fully compatible with the geological structures of the region. The calculation of the sinusoidal coefficient has shown that this river is a meandering river whose wavelength, the amplitude of the oscillation and the width of the meander belt are smaller in the mountainous area than in the plain area The gradient of the river bed is relatively low and it is classified as an erosion and sedimentation river in its different sections. The Gian River has a rocky bed in the mountainous part and an alluvial bed in the plain. The Gian River has a small catchment area, and, according to theGravelius' coefficient, its shape is almost elongated. The catchment elevation of the Gian River is between 1455 and 2700 with a weighted average of 1715.20 m.a.s.l. and its area decreases with the increase in the elevation. The concentration time of the catchment is 4.204 hours. The application of the data and results of the research can be very effective in land use planning, engineering and executive applications to predict river changes and protect engineering structures such as roads, bridges, coastal structures and railways, protect agricultural lands in the region and develop tourism.
Khadijeh Kord, Heeva Elmizadeh, Hakimeh Amanipour,
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)
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.
Mister Hamzeh Torkamanitombeki, The Doctor Mashalah Khamehchiyan, Mistress Maryam Nazari, Mister Shazdi Safari,
Volume 17, Issue 3 (Autumn 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.
Khandani, Atapour, Yousefi Rad, Khosh,
Volume 17, Issue 3 (Autumn 2023)
Abstract
Backfill materials used to fill underground mines are a type of engineered material whose particle size distribution (PSD) directly affects their mechanical and physical properties. According to the authors' review, there is no comprehensive standard for the properties of aggregates used in underground mine backfill materials. In this paper, the particle size ranges and particle size distribution curves of various mine backfill materials, including hydraulic backfill, paste backfill and rock backfill, have been reviewed. The available data on different types of backfill materials were collected. Based on the collected data, the smallest particle size, the largest particle size and the PSD curve ranges for each type of backfill material were determined. Then the characteristics of the particle size distribution curve of each backfill material, including the mean particle diameter (D50), the uniformity coefficient (Cu) and the curvature coefficient (Cc), were calculated. The results of the analysis of the PSD curves for paste backfill, hydraulic backfill and rock backfill materials showed that the particles in rock backfill and paste backfill had the largest and smallest sizes, respectively. Finally, the particle size distribution characteristics of a new backfill material prepared from construction and demolition waste (CDW backfill) are presented and compared with the particle size distribution of each of the conventional backfill materials. The results indicate that the PSD curve of the CDW backfill lies at the upper limit of the range of the particle size distribution curve of hydraulic backfill and at the lower limit of the range of the particle size distribution curve of rock backfill.
Prof. Mohammad Nakhaei, Dr. Amin Mohebbi Tafreshi, Dr. Tofigh Saadi,
Volume 17, Issue 4 (Winter 2023)
Abstract
A sharp drop in groundwater level as a result of indiscriminate extraction over a long period of time leads to the drying up of groundwater flows, which is called the phenomenon of groundwater drought. In this regard, this research aims to investigate the process of change and reduction of groundwater level, which is characterised by the phenomenon of groundwater drought. Based on this, the Groundwater Resource Index (GRI) was used to evaluate the drought condition of groundwater and analyse its spatial and temporal patterns based on groundwater level data of 21 observation wells between 1993 and 2019. ArcGIS software was used to create zone maps. The results of the research show that certain areas of the study area have experienced moderate to severe drought since 2001. In addition, the GRI zonation maps show that the southern and south-eastern regions of the aquifer have been more sensitive to drought than other parts of the aquifer during the defined period. The spatio-temporal pattern of groundwater drought in the aquifer shows that after a period of moderate drought from 2001 to 2003, the condition of the aquifer improved slightly, and generally stable conditions were established from 2001 to 2010, but since 2011, the occurrence of drought has intensified and the aquifer has been in severe to very severe drought conditions. These conditions highlight the need for careful attention and implementation of management measures. One of the study's recommendations is to use satellite data on groundwater levels to assess the progress of the drought, and compare it with the findings of this study.
Dr Masoud Amelsakhi, Eng Elham Tehrani,
Volume 17, Issue 4 (Winter 2023)
Abstract
This research is a laboratory study to improve the geotechnical properties of sandy soils. Concrete waste with a grain size of 1.2 to 1 inch was used for this purpose. The effect of using concrete waste at 0, 10, 20 and 30 weight percent on dry sandy soil in two loose and dense states was investigated. Based on the results of the direct cutting test, the addition of concrete waste has increased the shear strength and the internal friction angle of the soil; The loose samples made with ٪30 of concrete waste had the greatest effect, so adding ٪30 of concrete waste to loose sand increased the internal friction angle of the soil by ٪32 and the shear strength by ٪42 Similarly, adding ٪10 of concrete waste to dense sand increased the internal angle of friction of the soil by ٪4 and the shear strength by ٪6.
Eng. Zahra Soleimani, Dr. Ebrahim Rahimi, Dr. Houshang Khairy,
Volume 18, Issue 1 (Spring 2024)
Abstract
This article deals with the strength evaluation of concrete obtained by adding different percentages of three types of nanominerals, including nanocalcite, nanobarite and nanofluorite. To measure the velocity of ultrasonic waves and compressive strength of concrete, 15×15×15 cm cube samples were prepared with 7-, 28- and 90-days curing. 10 types of mix designs with 0.39 water-cement ratio, including the control sample (without additives) and the samples with 0.5, 0.75 and 1% nanominerals were subjected to the mentioned tests. The results showed that the addition of nanocalcite, nanofluorite, and nanobarite with values of 0.75%, 1%, and 0.75%, respectively, have the highest compressive strength compared to the control sample. Although these do not have pozzolanic properties, they play a positive role in increasing the concrete strength by filling concrete voids and due to their high specific gravity, increasing concrete density.
