vahid joudaki; Rasoul Ajalloeian; Jafar Hassanpour
Abstract
In massive mechanized tunneling projects, there is a need for extensive geological studies. These studies require sufficient knowledge of various fields of geology . In this research, the view of graduates of engineering geology, about educational and industrial experiences has been studied.This research ...
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In massive mechanized tunneling projects, there is a need for extensive geological studies. These studies require sufficient knowledge of various fields of geology . In this research, the view of graduates of engineering geology, about educational and industrial experiences has been studied.This research is a descriptive survey. The research population consisted of all active engineers of geology in the country. By using simple random sampling, 50 people were selected. Data were collected by a researcher-made questionnaire, and data were interpreted using descriptive statistics.The results of the survey show that in many specialized courses and in undergraduate practical units, technological applications of topics in related industries have not been addressed. From the perspective of the population of the statistical community, the current curriculum needs to be reviewed and new lessons need to be developed. The results show that a small part of the students' practical units in applied spaces are performed. According to people, in the field of postgraduate studies, a significant proportion of theses have a theoretical and fundamental aspect. On the other hand, there is no research collaboration in interdisciplinary research between geological colleges and engineering faculties (electronics, mechanics, etc.). .The results show that, in the current situation, the revision of educational topics and the wider activity of geological associations can enhance the potential of geology graduates in industrial jobs. Therefore, in this paper, with a brief overview of the conditions of geological groups and the country's mechanized drilling industry, suggestions are presented to solve the challenges.
Z. Jorkesh; R. Ajalloeian; A. H. Sadeghpour; M. J. Kalantar Hormozi
Abstract
In this research, the effect of salinity on engineering characteristics of sandstones is investigated. For this purpose, two sandstones from abutments and rock fill (Rip-Rap) of Vanyar dam (in Eastern Azerbaijan province) were selected in addition to three water samples (drinking water, semi-brine and ...
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In this research, the effect of salinity on engineering characteristics of sandstones is investigated. For this purpose, two sandstones from abutments and rock fill (Rip-Rap) of Vanyar dam (in Eastern Azerbaijan province) were selected in addition to three water samples (drinking water, semi-brine and brine) to saturate these rock samples. Water content, uniaxial compressive, point load, thawing and freezing, sound velocity, and durability tests were carried out on dry and saturated samples at different time intervals. After 5 months of submerging type 1 and 2 sandstones in brine water, the uniaxial compressive strength values were decreased 13 and 4%, respectively, and after 10 months to 12 and 0.2%, respectively, compared to those of samples prepared using drinking water. By increasing the salinity of the water, the durability values after 10 cycles changed from 2.3 to 4.2% and from 1.8 to 3.2% for sandstones types 1 and 2, respectively. The sound velocity in a dry sample of sandstones types 1 and 2 was measured as 4450 and 4950 m/sec, respectively, while they reached 4699 and 5255 m/sec, respectively, by increasing salinity. The results show that brine water almost has no effect on thawing and freezing.
Exploration and Mining
V. Joudaki; F. Koohiyan-Afzal; A. Aalianvari; R. Ajalloeian; A. Sohrabi-Bidar
Abstract
Part 4 of Ghomroud tunnel is located in the Sanandaj-Sirjan geological zone. In this area, due to the existence of numerous faults, crushed zones and significant development of major and minor catchments, the tunnel has been encountered with the risk of groundwater influx. On the other hand, due to some ...
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Part 4 of Ghomroud tunnel is located in the Sanandaj-Sirjan geological zone. In this area, due to the existence of numerous faults, crushed zones and significant development of major and minor catchments, the tunnel has been encountered with the risk of groundwater influx. On the other hand, due to some limitations such as thick(up to 600 meters in some localities)overburden over the tunnel and the lack of exploratory drilling down to the tunnel level, it has been difficult to forecast and estimate the groundwater flow in the tunnel route. Due to the existence of numerous faults in part 4 of the Ghomroud tunnel ,encountering of the drilling machine (Double Shield TBM) with high-pressure water could cause influx of large amounts of water into the tunnel and collapse of rock masses in the crushed zones. It hence could cause deviation of the machine and drilling stop. In this article, the lack of data from boreholes led us to try investigating the development of groundwater flow in the tunnel based on geomorphological evidence. Analytical modeling and geomorphological field survey in the area show a relative consistency between geomorphology and volume of water flowing in the tunnel excavation. Therefore, according to measurements conducted on the water entering the tunnel, about 80 liters per second of water flowed into the tunnel, which is in agreement with geomorphological studies. Results show that the study of morphology and surface features could provide useful information in order to identify more precisely the hydrogeologic conditions of the area.
V Joudaki; R Ajalloeian
Abstract
In the present case study, a thick overburden above the Ghomroud tunnel locally reaching about 600 meters plus the existence of many fault/crushed zones along the tunnel led the full-face Tunnel Boring Machine (TBM) to encounter squeezing and collapsing of materials. In parts 3 and 4 of the tunnel, a ...
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In the present case study, a thick overburden above the Ghomroud tunnel locally reaching about 600 meters plus the existence of many fault/crushed zones along the tunnel led the full-face Tunnel Boring Machine (TBM) to encounter squeezing and collapsing of materials. In parts 3 and 4 of the tunnel, a combination of these problems caused long-term and frequent pausing in digging processes (about 600 days). The plan is situated in the Sanandaj-Sirjan geological zone. Because of intense tectonic deformations through time, this zone consists of series of rock units, which have experienced moderate to high metamorphisms that caused schistosity and recrystallization of minerals. In the present paper, in addition to preparing thin sections of rocks for microscopic studies, the role of geological conditions with an emphasis on formation petrology is investigated to explore excavation hazards along the tunnel. Hence, by traversing along the axis of the tunnel, several samples were taken from the rocks exposed on surface and from those in the tunnel. Most problems occur in the foliated Jurassic rock units and in sections where faults and relatively thick tunnel overburden (high in-situ stress) have made the geological condition unfavorable. Results show that the petrological properties (texture, mineralogy, etc.) of the extensively foliated rock masses (schist, slate, graphite schist) and their interbedding with strong units (Quartz and quartzite veins) along with other geological factors have been effective on the occurrence of hazards and TBM pausing. Results of Cerchar abrasiveness index test also indicate high hardness and strength of quartzite veins, which played an important role in creating mixed face conditions and amplifying the hazards in easily squeezing and collapsing materials.
