Browsing by Author "Özvan, A."

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Capital City of the Oldest Civilization: Hasankeyf T- Turkey
(2009) Yilmazer, O.; Orhan, A.H.; Yilmazer, I.; Özvan, A.; Bekiroǧlu, S.
Hasankeyf is the last standing down loop of the Northern Mesopotamia whereas the Munzur is the upper one. The geology of the area, for 65 million years, with its admirable outstanding features indicating evolution of the region is flowering there. Why are the assaults on Hasankeyf, which served inhabitants and formed a comfortable cradle for various civilizations for the last 12,000 years? The assailants mainly claim that (a) energy shortage and (b) irrigation problems will be solved by the Ilisu dam. All of their claims unrealistic...! Since 1946 they killed thousands of natural and historical monuments and heritages in Anatolia to leave Anatolia as an empty sack by putting forward the same unrealistic arguments. First of all, the very fertile soil forms flood areas of the main rivers such as Tigris and Euphrates. Dams invade at first the fertile alluvial soils at the flood bank then of the relevant streams, fertile soil (colluviums) accumulated along the mountain toes bounding the alluvial soil. Hence there will remain no land to irrigate. Every dam has certain time limit to be used. It might be a few decades. Then, there will be no energy and no irrigation. Additionally, it continues to emit methane (CH4) which is 21 times more disastrous than CO2 in regards with global warming processes. The project TIDE- abbreviation of Terracing - Torricelli - Turbine - Irrigation - Dyke - Energy-proposed as an alternative to the Ilisu dam project provides; a. 90% reduction in cost, b. Twice more energy, c. Twelve times more farm land to be irrigated, d. 99% reduction in land acquisition, e. Easy protection and conservation of the natural monuments, f. Effective preservation of the historical and cultural heritages forever, and g. Numerous superiorities from standpoint of • timing, • environment, • safety-security, and • Cost (TESC). © 2009, INSInet Publication.
Determination of Dynamic Soil Properties of Van Yuzuncu Yil University Campus for the Preparation of Microzonation Map
(TMMOB - Jeoloji Muhendisleri Odasi, 2015) Akin, M.K.; Akin, M.; Akkaya, İ.; Özvan, A.; Üner, S.; Selçuk, L.; Tapan, M.
One of the most important factors causing loss of life and property during earthquakes is the soil conditions that the structure is built on. Determination of the soil engineering properties for understanding the behavior of ground under dynamic loads and/or minimizing the losses that may occur is quite crucial. The earthquakes occured in our country especially in 1999 and later on, and the resulting loss of life and property once more emphasized the importance of the social and economic dimensions of the impact created by the earthquake. Dynamic soil properties must be studied in accordance with the principles of microzonation considering the natural disasters such as earthquake. For this aim, the dynamic soil properties of Van Yuzuncu Yil University campus area are determined. Liquefaction, soil amplification and the like for the campus area are investigated through field studies conducted in order to reveal the ground conditions, and consequently the suitability for settlement is evaluated to guide the future planning of the campus. © 2015, TMMOB - Jeoloji Muhendisleri Odasi. All Rights Reserved.
Evaluation of Availability of Delihalil Basalt Levels (Eastern Mediterranean) for Rubble Mound Breakwater
(TMMOB - Jeoloji Muhendisleri Odasi, 2015) Özvan, A.; Acar, İ.A.
Rubble mound breakwater is one of the most important structures for shore and harbor. Durable and high quality natural rocks are commonly used to protect coastal engineering structures from the waves. In this study, numerous laboratory tests were performed for the quality assessment of different basalt levels for rubble mound breakwater in the Yumurtalik (Eastern Mediterranean) region in this study. Two different basalt types were observed in study area. These levels were evaluated with different rock quality classification systems. Basalts were grouped into two classes as massive and vesicular. Idding site is a product of alteration of olivine minerals, which are commonly observed in the vesicular basalt. Vesicular basalt levels showed poor rock material strength due to alteration. The vesicular basalt levels in the study area should not be used for armourstones. © 2015, TMMOB - Jeoloji Muhendisleri Odasi. All Rights Reserved.
Geotechnical Handicap of Travertine With Different Lithotype Levels as Foundation Material
(Geological Society of India, 2016) Özvan, A.; Erdogan, O.
Two major earthquakes occurred on October 23rd, 2011 (M=7.1) and November 9th, 2011 (M=5.6) in Tabanli and Edremit districts of Van province in Turkey, respectively. New settlement areas for Van city were determined after these destructive earthquakes. One of the most important areas for new settlements to be built was Edremit region, consisting travertine where nearly 80% of new housing units (12.384) were built by TOKI (Housing Development Administration of Turkey). Travertines have different lithotypes depending on their depositional process such as crystalline crust, shrub, reed which can affect mechanical and engineering properties of travertine and each level has different handicaps. The purpose of this study is to investigate the relationship between lithotype and physico-mechanical properties of travertines. According to the results, lithotype has an effect on physical, mechanical and rock mass properties of travertine. It is ascertained by several research methods that various handicaps may occur on such areas when the active tectonic structure of the area is evaluated along with the karstic cavities within the travertine and different lithotype qualities. © 2016, Geological Society of India.
The Role of Capillary Water Absorption Characteristics of Ignimbrites on the Deterioration of Ahlat Seljuk Tombstones
(TMMOB - Jeoloji Muhendisleri Odasi, 2016) Akin, M.; Dinçer, İ.; Özvan, A.; Oyan, V.; Tapan, M.
The Seljuk Tombs of the Seljuk Empire in the Ahlat region are included in UNESCO’s World Heritage Tentative List due to the fact that the tombstones are known to be the largest graveyards of Muslims with their historical significance. Tombstones were erected using ignimbrite type pyroclastic rocks which are widespread in the region, and several inscriptions and patterns were carved on them thanks to their softness and easy processing. However, these tombstones have been subjected to weathering effects for almost a duration of 800 years. The most striking point after the inspection of tombstones is that many of them were broken from the middle section. In this study, experimental studies were carried out on fresh ignimbrite specimens and particularly the effect of capillary water absorption on deterioration was investigated to reveal the factors leading to deterioration of Ahlat Seljuk tombstones. Accordingly, high porosity and capillary water absorption characteristics of the ignimbrites are found to be the major reasons for the deterioration of tombstones. © 2016, TMMOB - Jeoloji Muhendisleri Odasi. All rights reserved.
Some Comments and Suggestions for Wide Wheel Abrasion Test Used To Determine the Abrasion Resistance of Marbles
(TMMOB Chamber of Geological Engineers, 2020) Özvan, A.; İnan, E.
The most widely used standard test methods for determining wear of the marbles are Wide Wheel (Vertical) Abrasion (WWA) and Böhme Abrasion (BA) tests. In this study, it was aimed to determine the effect of the counterweight loads applied in the WWA experiment, sample surfaces with polished and matte surfaces and different abrasive powders on the test results. In this study, a total of 48 (7x10x3cm) samples were used for the WWA tests and 24 (7x7x3cm) samples were used for the BA tests. As a result of the experiments, it was determined that the matte surfaces of the marble samples reveal more accurate results in the abrasion tests. When both artificial corundum and corundum (white fused alumina) powder are used in WWA and BA experiments, similar abrasion values are obtained on the samples. In addition, it is determined in the WWA experiment that the anisotropy of the sample is important and the counterweight affects the groove shape. © 2020, TMMOB Chamber of Geological Engineers. All rights reserved.
Springwater Chemical Anomalies Prior To the Mw = 7.2 Van Earthquake (Turkey)
(2012) Inan, S.; Yakan, H.; Balderer, W.P.; Leuenberger-west, F.; Özvan, A.; Freund, F.T.
We performed chemical analyses of commercially bottled spring water (EREK Spring water) emanating from a location less than 20 kilometer from the epicenter of the Mw = 7.2 Van Earthquake of October 23rd 2011. The available water samples cover the period from September 8th 2011 to January 11th 2012. The pre-earthquake anomaly is characterized by a slight but clear increase in Ca2+, Mg2+, K+ and Cl- contents and decrease in Na+ and SO42- contents compared to the background. Post-seismic samples show decreasing trends in Ca2+, Mg2+, K+ and Cl- and increasing trends in Na+ and SO42-. All ion concentrations reach stability approximately one month after the earthquake. These results indicate that spring water chemical anomalies may be monitored as potential geochemical pre-earthquake indicators. © 2012, GEOCHEMICAL SOCIETY OF JAPAN. All rights reserved.