S. M. Fatemi Aghda; K. GanjaliPour; K. Nabiollahi
Abstract
Due to the expansion and application of technology in soil and rock mechanics, engineering geology and geotechnics, it is possible to use newer, faster and cheaper methods in these fields every day. TDR technology is one of these methods. This technology has been developed by the telecommunication and ...
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Due to the expansion and application of technology in soil and rock mechanics, engineering geology and geotechnics, it is possible to use newer, faster and cheaper methods in these fields every day. TDR technology is one of these methods. This technology has been developed by the telecommunication and electricity industry to determine the location of cable faults. The radar is a prime example of the TDR. The basis of this technology is the sending of a short pulse of energy (electromagnetic pulse) that is reflected in the collision with some anomalies. The point location of these anomalies can be determined if the velocity and direction of the pulse can be determined. The electromagnetic pulse reaches the waveguide through the conductor cable and enters the test environment. In this research, this method was used to determine the groundwater level in the Darian dam. The TDR has the ability to detect the air-water interface, and the reported results are consistent with the measured data using traditional methods. Also in one of the situations that are prone to slide, coaxial cable was installed as TDR sensor. The results showed that the TDR recognizes the shearing and stretching zones in the cable as the result of the ground movement successfully. Finally, since manual processing of TDR data was very difficult and requires high accuracy and time, a method for computer processing of this data was provided by the authors.
M Kamani; A Uromeihy; M Joorabchi
Abstract
Roads are of linear engineering projects passing various rock units and geological conditions, so it is necessary to engage the engineering geological studies along the way. The studies continue until the end of the construction and operation. In the route selection process, large volumes of data and ...
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Roads are of linear engineering projects passing various rock units and geological conditions, so it is necessary to engage the engineering geological studies along the way. The studies continue until the end of the construction and operation. In the route selection process, large volumes of data and different track conditions are facing. To perform this manually is time consuming and not accurate enough. This study examines the status of engineering geology freeway route Qazvin - Rasht in Roudbar discussed in this context, the factors affecting engineering geology route selection and construction of the freeway, using the Analytical Hierarchy Process (AHP) and Expert Choice software to give weight of these factors, according to their suitability for the construction of freeways, and then layers weighted overlay in GIS software and the final map has been prepared. The final map shows the quality of route engineering geological conditions, which is provided for both surface and subsurface (tunnels) with the least error. Since the procedure for engineering geological survey route is a new method, it requires further investigation and to test in other places in order to be much more modified and corrected. On the other hand, this model can be used for other engineering geological investigations due to high flexibility of this model.
G. Barzegari; A. Uromeihy
Abstract
Development of liquefaction in saturated cohesionless deposits is one of the most dramatic causes of damage in civil structures during earthquakes. The potential damage caused by liquefaction includes: 1) loss of bearing capacity, 2) excessive settlement, 3) lateral spreading, 4) flow failure, and 5) ...
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Development of liquefaction in saturated cohesionless deposits is one of the most dramatic causes of damage in civil structures during earthquakes. The potential damage caused by liquefaction includes: 1) loss of bearing capacity, 2) excessive settlement, 3) lateral spreading, 4) flow failure, and 5) ground oscillation.
The liquefaction susceptibility of a specific deposit is affected by many factors for example, wave-induced liquefaction characteristics, soil type, geological history, confining pressure, permeability, relative density, water content, and properties of the soil grain size.
Chapar-Abad Dam is an inhomogeneous earth-fill dam with height and crest length of 44.5 and 427 meters, respectively. The reservoir capacity is 127 million cubic meters. The dam which is under construction is located about 75 km southeast of UromiehCity, in West-Azerbaijan province. The foundation materials include 60 meters of alluvium deposits overlying the bedrock layers of carbonate units. The abutments consist of carbonate and schistose layers of Precambrian age. In this paper the potential of liquefaction of the site is evaluated according to the SPT results form in-situ tests performed in boreholes driven into the depth of alluvial deposits. Furthermore, recently modified relations of correction factors such as stress reduction factor (rd), earthquake magnitude scaling factor for cyclic stress ratios (MSF), overburden correction factor for cyclic stress ratios (Ks), and the overburden normalization factor for penetration resistances (CN) are presented and used in liquefaction assessment of alluvial foundation at Chapar-Abad Dam. The results indicate the possibility of liquefaction and instability of granular soils during earthquake and any types of strong motions.
