Effects of engineering geological properties of Gachsaran Formation gypsum on karst development (Khuzestan, Ramhormoz)
Mohammad Hosein
Gobadi
Prof. of engineering geology, Bouali University
author
Mohammad
Mohamadian
. M.Sc. student of Engineering Geology, Department of Geology, Bu-Ali Sina University, Hamedan, Iran.
author
Hasan
Mohseni
Associate Professor , Department of Geology, Bu-Ali Sina University, Hamedan, Iran.
author
Ramin
Karami
Ph.D. student of Engineering Geology, Department of Geology, Ferdowsi Universty, Mashhad, Iran
author
text
article
2014
per
Karstification develops in gypsum easily due to high solubility. In this paper, determine geological engineering properties of Gachsaran Formation gypsum from Ramhormoz area and has been related with karst development by petrological and rock mechanic studies. ANFIS as combines fuzzy logic and neural networks in the form of neuro-fuzzy method were used for detect type of gypsum. Input data include uniaxial compression strength, tensile strength, durability Index and porosity percentage from 80 laboratory samples. ANFIS was built model that with little knowledge of rock, was able to predict the type of rock. Based on petrographic studies, Gachsaran Formation gypsum with two different textures has been considered, fine grained (alabastrine) and coarse grained (porphyritic) gypsum. The results indicate that texture, especially grain size and shape, is an important parameter controlling the differences in the mechanical properties of the two gypsum types studied. Based on intact rock engineering classification, alabastrine gypsum and porphyritic gypsum classification as DH and EH category respectively. Alabastrine gypsum than porphyritic gypsum has more unconfined compressive strength, tensile strength, solubility and brittle behavior so karstic phenomena such as dissolution sinkhole , karstic wells(jamas), natural roof and caves are more spread in them. Porphyritic gypsum than alabastrine gypsum have more slake durability and less strength so collapse and subsidence sinkholes are more spread also karren and pinnacles are bigger in them.
Scientific Quarterly Journal of Iranian Association of Engineering Geology
Iranian Association of Engineering Geology
2228-5245
6
v.
شماره 3 و 4
no.
2014
1
16
https://www.jiraeg.ir/article_68329_1fd13a63950fa3d315a4fa1335c8325e.pdf
Application of 2D electrical resistivity for geometry investigation
of Noghol-Semirom landslide
Ahmad
Ghorbani
Assistant Professor, Yazd University, aghorbani@yazduni.ac.ir
author
Mahdi
Bemani
Ph.D. student, Yazd University, bemanimahdi@gmail.com
author
Abdolhamid
Ansari
Associate Professor, Yazd University,
author
Hosseinali
Ghari
Ph.D. student, University of Tehran, hosseinali.ghari@gmail.com
author
text
article
2014
per
The Noghol landslide is located in Padena region in Semirom area in Isfahan province, Iran. The Noghol Landslide has a triangle form with a movement by E-W direction. The overall movement in landslide is from east to west toward to the Dengezloo river. The area influenced by the movement of landslide is about 600 by 700m. Landslide is occurred in the Bakhtiyari formation (massive to thick-bedded conglomerate with interbedded sandstone and marl belong to Cenozoic era). ERT surveying is carried out on the six profiles (parallel and perpendicular to the landslide direction) using a Dipole–dipole array. The total length of traverses is about 3 kilometres. Landslide is limited by a fault (strike NW-SE) from the north side and a permanent river from the west side of landslide. Conglomerate and marl are placed on the north and south sides of the fault, respectively. ERT survey yielded important information about the geometry and characteristics of the landslide. ERT results also show that two main sliding surfaces are present in Noghol landslide: a sliding surface in depths shallower than 20 m. On the outcrop of marl formation, normally, weathered surface creates a sliding surface. The second is a sliding surface in nearly 50 m depth. Here, right flank of landslide is formed by fault. Sliding surface is created when marl formation is partially saturated. So, both shallow and deep-seated landslide can be recognized in studied landslide. This information is confirmed by geological and borehole investigations.
Scientific Quarterly Journal of Iranian Association of Engineering Geology
Iranian Association of Engineering Geology
2228-5245
6
v.
شماره 3 و 4
no.
2014
17
32
https://www.jiraeg.ir/article_68330_612b55c29ba22dc535149e273b23c5cc.pdf
Evaluation and zonation of liquefaction potential of coastal deposits
(case study: coastal region of southern Pars gas-field)
Abbasali
Mohammadi
M.sc. student, Department of Engineering Geology, Tarbiat Modares University, Tehran, Iran
author
Ali
Oromiehei
P{rof. of Engineering geology Tarbiat Modares University
author
Kazem
Moradi Hersini
Ph.D. of Engineering Geology, Sazeh Pardazi Consulting Engineers Company, Tehran, Iran
author
text
article
2014
per
Liquefaction is considered as natural hazard that directly affect the stability of infrastructures projects. The potential of liquefaction for an area is controlled by many factors including the type of soil, water presence and the seismicity risk. South Pars region is located to the southern part of Bosheher Province which is recognized as developed industrial area and include many lifeline and sensitive projects. From the geological point of view, the study area is formed as an alluvial fan which consists of loose and young deposits that is a mixture of clay, silt, sand and gravel layers. In this research, investigation reports of the phases 12, 14, 19 and many related reports of the coastal part of southern Pars Gas-field were collected and studies. The N values calculated from SPT tests and other geotechnical data for 60 boreholes were used to evaluate the liquefaction potential of the sand layers. Due to the large amount of the reviewed data, the information of only 16 boreholes were presented in this paper. The results showed that during the event of large earthquake of magnitude of 7 on the Richter scale and production of horizontal acceleration at 0.3g, liquefaction occurrence in the region at phases 12 and 19 is possible. Based on the calculation of liquefaction potential index (LPI), the results showed that by approaching the coast line the potential of liquefaction of sand deposits is increased due to high percentage of soil saturation. In contrast, by distancing from the coast line towards the land this potential is decreased due the increment of soil gradation.
Scientific Quarterly Journal of Iranian Association of Engineering Geology
Iranian Association of Engineering Geology
2228-5245
6
v.
شماره 3 و 4
no.
2014
33
46
https://www.jiraeg.ir/article_68331_b6f06d3e57f054b44622123bab4b2afc.pdf
Modeling of subsidence in south Pars as field using analytical and semi analytical methods
Mahmoud
Fatemi Aghda
Prof. of Engineering Geology Kharazmi University
author
Akbar
Ghazifard
Associate professor, Department of Geology, Esfahan University, Esfahan, Iran
author
Mohammad Hossein
Taherinia
Ph.D. student of Engineering Geology, Department of Geology, Kharazmi University, Tehran, Iran.
author
text
article
2014
per
Exploitation of hydrocarbon reservoir would cause decrease in pore pressure and increase of effective stress applied to reservoir rock, which result in compaction of reservoir. If the reservoir compaction exceeds certain limit, the overburden rocks of reservoir due to their weights begin to subside. With respect to the importance of South Pars gas field which belongs to Iran and Qatar, calculation and modeling of field surface subsidence is very important. In this paper for determination of South Pars Gas field subsidence, at first, the reservoir compaction with use uniaxial compaction theory was calculated and then the effect of this compaction on the field surface with use analytical and semi analytical method was modeled. The amount of South Pars reservoir compaction at the end of production period reached up to 0.5 meter and according to the results of two subsidence modeling methods, maximum subsidence value will reach to over 0.6 meter.
Scientific Quarterly Journal of Iranian Association of Engineering Geology
Iranian Association of Engineering Geology
2228-5245
6
v.
شماره 3 و 4
no.
2014
47
58
https://www.jiraeg.ir/article_68332_e8e74ec93de640526c65994d1e9d4a5c.pdf
Evaluation of indentation method in determining fracture toughness of rocks
Mahdi
Zare Najafabadi
1. Fatigue and Fracture Research Laboratory, School of Mechanical Engineering, Iran University of Science and Technology,
author
Majidreza
Ayatollahi
. Fatigue and Fracture Research Laboratory, School of Mechanical Engineering, Iran University of Science and Technology, m.ayat@iust.ac.ir
author
text
article
2014
per
Fracture toughness is an important parameter in some applications related to rock masses like fracture of rock, hydraulic fracturing process, design and manufacturing of tunneling apparatus. Different methods have been proposed for determining fracture toughness of quasi-brittle materials including the indentation test. In this research, the properties of some rocks with different textures (grain size and shape) are examined in the indentation test. Then applicability of the indentation method in determining fracture toughness of rocks is evaluated. It is shown that rocks exhibit two different types of behavior in the indentation test. For forces less than a critical force, rocks behave in accordance with other brittle materials, while for loads more than the critical force, the rocks behave completely in contrast with other brittle materials. This difference makes the indentation method an unsuitable option for determining fracture toughness of rocks. The main reason for this difference could be the presence of inherent defects in rocks.
Scientific Quarterly Journal of Iranian Association of Engineering Geology
Iranian Association of Engineering Geology
2228-5245
6
v.
شماره 3 و 4
no.
2014
59
68
https://www.jiraeg.ir/article_68334_f1b991f56e4468f798100bf38fb6d266.pdf
Correlation of microscopic mineralogical and textural properties versus physical and mechanical properties of gabbroic and diorite rocks in Natanz area
Masood
Torkan
MSc Student of Rock Mechanics, Department of Mining Engineering, Isfahan University of Technology.
author
Mohammadreza
Irannezhadi
Assistant Professor, Department of Mining Engineering, Isfahan University of Technology.
author
Alireza
Baghbanan
.Associate Professor, Department of Mining Engineering, Isfahan University of Technology.
author
text
article
2014
per
Microscopic and geomechanical properties of construction igneous rocks include the degree of alteration, the presence of microfractures, peak strength, porosity, the proportion of detrimental minerals, etc. As reported in the literature, porosity in igneous rocks has a significant negative on the peak strength of rock samples. In this research, samples of gabbro and diorite rocks from a construction stone quarry in west of Natanz were selected and subject to microscopic and geomechanical investigations. As per thin section investigations, the degree of alteration, the presence of microfractures, and the minerals detrimental to the strength of construction stones were studied. Therefore, the geomechanical experiments including determination of density, porosity, durability index, the Brazilian and triaxial tests were conducted. The obtained data were compared to standard values and consequently a qualitative correlation between strength and microscopic properties was detected, accentuating the importance of microscopic studies in the investigations upon construction stones. The correlation thereupon may be applied in the different stages of exploration, exploitation, and processing of the construction stones and in order to avoid prodigious costs and destruction in the environment and domestic resources.
Scientific Quarterly Journal of Iranian Association of Engineering Geology
Iranian Association of Engineering Geology
2228-5245
6
v.
شماره 3 و 4
no.
2014
69
78
https://www.jiraeg.ir/article_68335_d36b92da1d7c484fc54d422a0b2be448.pdf
Laboratory investigating of mixed soil-shred tire behavior for application
in railway track subgrade
Morteza
Esmaeili
Associate Professor, Iran University of Science & Technology, School of Railway Engineering,
author
Navid
Nakhai
2. Iran University of science & Technology, School of Railway Engineering,
author
text
article
2014
per
One of the suggested applications for use of waste tire is mixing of this material with soils in shredded form for use in retaining walls backfill and embankments. In this regard, comprehensive studies have been accomplished in the field of road engineering but no research works could be found in the railway engineering. As one of the important parameters is railway embankment design is Ev2 (modulus of elasticity in the second loading cycle in PLT) so this research is devoted to investigating of physical and mechanical behavior of soil mixed with shred tire. For his purpose by using the GW-GC as a base material which can be used in railway embankment and subgrade, it is mixed with three different percent 5, 10 and 15 of shred tire with range of aggregation 0.475 to 2.5 centimeters. In continue a series of physical and mechanical tests are performed on base soil and soil mixed with shred tire including compaction, sand equivalent, CBR, direct shear test. In the last stage of the laboratory investigations four cyclic plate loading tests are performed in loading chamber box with dimensions of 2.5×2.5×1.2 m respect to base soil and it mix with 5, 10 and 15 percent shred tire. It should be notified that the soil in all four tests the soil are compacted based on guidelines of ASTM D6270-2006. The plate dimensions in PLT test are considered as 30×30 cm. The obtained results indicate that due to increase in shred tire percentage in the range of 5 to 15 percent, the maximum dry density decreases form 11.86 to 19.36 percent respect to the base soil. On the other hand the CBR value show 34.35 to 67.47 percent and Shear strength parameters such as cohesion the First, increased to 2.1 percent, but then decreased back to levels 27.1 percent and Angle of internal friction value has been reduced by 10.8 to 21.67 percent decrease in the mentioned range. Focusing on the obtained Ev2 values in PLT tests reveals a decrease of 27.54 to 54.29 percent in this matter. Comparing the achieved Ev2 results with those proposed by UIC R719-1996 code confirms the limitation of shred tire application to 10 percent for use in subgrade layer while its use in embankment is forbidden.
Scientific Quarterly Journal of Iranian Association of Engineering Geology
Iranian Association of Engineering Geology
2228-5245
6
v.
شماره 3 و 4
no.
2014
79
88
https://www.jiraeg.ir/article_68336_b03a64876e99485912857a65d2c6a8c6.pdf
Estimation of uniaxial compressive strength of limestone marls from Abderaz formation by using physical properties
Masoomeh
Khalili
Department of Geology, Ferdowsi University of Mashhad, Mashhad, Iran
author
Gholamreza
Lashkaripour
Department of Geology, Ferdowsi University of Mashhad, Mashhad, Iran
author
Mohammad
Ghafoori
Department of Geology, Ferdowsi University of Mashhad, Mashhad, Iran
author
Mohammad
Khanehbad
Department of Geology, Ferdowsi University of Mashhad, Mashhad, Iran
author
Pourya
Dehghan
Department of Geology, International Branch of Ferdowsi University of Mashhad, Mashhad, Iran.
author
text
article
2014
per
the purpose of this study is presenting and study of simple equations to estimate the uniaxial compressive strength of marly limestone of Abderaz formation. Many engineering structures such as dam, tunnel and road have been constructed on this formation in the northern part of Khorasan Razavi province. For determation physical parameters and uniaxial compressive strength of marly limestone, 39 samples according to the International Society of Rock Mechanics Standards (1981) of Abderaz formation were collected. Physical properties which determined including of porosity, density, water absorption. Results which obtained from the simple regression method, indicating a better relationship between density and uniaxial compressive strength in comparison with the other physical properties. The best multivariate correlation is obtained between uniaxial compressive strength with density and water absorption.
Scientific Quarterly Journal of Iranian Association of Engineering Geology
Iranian Association of Engineering Geology
2228-5245
6
v.
شماره 3 و 4
no.
2014
89
97
https://www.jiraeg.ir/article_68337_16cab7a9456033078b59c5c8e63ad711.pdf