I graduated from Hacettepe University Mining Engineering department in 2010. I got my MSc. and PhD. degrees from Karadeniz Technical University in 2012 and 2016, respectively. I was a visiting PhD student of The University of Queensland Geotechnical Engineering Centre for a year between 2014 and 2015. I carried out some Post-doc researchs at Karadeniz Technical University Mining Engineering Department between 2016 and 2018. Then, I worked as a Assist. Prof. Dr. at Civil Engineering Department of Giresun University from 2018 to 2020. Since 2020, i have been working as Assoc. Prof. Dr. at Civil Engineering Department of Giresun University. My research area is rock mechanics, tunnelling and support design, stability problems of underground mines and new support materials in rock engineering. I am writer of more than 60 scientific papers and winner of three international and a national awards for my studies on use of different engineering polymers as rock support and reinforcement materials. I have been working in different scientific research projects of my universities, site studies and geotechnical consultacy projects. As a member of Commission on Preservation of Ancient Sites of International Society of Rock Mechanics and Rock Engineering (ISRM), i also interest with conservation of historical rock engineering sites. History of geotechnical and mining engineering is another topic i love to interest in. I am head of the geotechnical division and Vice Chairman of the Civil Engineering Department of Giresun University since 2018.
ENGGEO’2024: National Symposium on Engineering Geology and Geotechnics, 2024
In this study, use of a new polypropylene geofiber type called microgrid fiber (MGF) was investig... more In this study, use of a new polypropylene geofiber type called microgrid fiber (MGF) was investigated in comparison with a conventional polypropylene fiber (PPF) product. California Bearing Ratio (CBR) values of a sand type soil reinforced with different polypropylene geofiber additives were investigated for different fiber ratios in soil mixes. Additionally, specimens without any fiber additive were also tested to compare their CBR values with the results obtained from the others. It was determined that both PPF and MGF additives supplied notably higher CBR values than those of the specimens with no fiber. As another outcome, MGF type fiber was found to increase the CBR values at higher rates in comparison with the conventional PPF product. It was assessed that MGF type novel geofiber additives can be used to make higher soil reinforcement performances rather than the conventional PPF products.
In this study, uniaxial compressive strength values of a sand type soil reinforced with polypropy... more In this study, uniaxial compressive strength values of a sand type soil reinforced with polypropylene fiber and silicate-based resin additives with different amounts were investigated. Microgrid fiber (MGF) was tested as a new polypropylene fiber additive in the experiments to compare it with a conventional polypropylene fiber type geosynthetic product used in soil fill improvement applications. According to the findings obtained from the uniaxial compressive strength (unconfined compressive strength) tests, it was determined that the new MGF type fiber usually increased the strength values at higher rates in comparison with the conventional fiber product. As another outcome, it was found that target strength values can be supplied by using less resin amounts for the specimens with fiber additives. It was determined that proper strength improvements can be obtained more economically by the fiber additive use together with the resin, rather than the resin added mixtures without the fiber.
International Journal of Mining, Reclamation and Environment, 2023
In this study, use of microgrid fiber (MGF) was tested as a new polypropylene fiber additive for ... more In this study, use of microgrid fiber (MGF) was tested as a new polypropylene fiber additive for cemented rock fill (CRF) mixes and compared with the conventional polypropylene fiber type geosynthetics. Changes in the uniaxial compressive strength and indirect tensile (splitting) strength values of CRF specimens were investigated for the use of different fiber types. In this experimental study, cemented basalt aggregate type rock fill materials were tested in case of using different amounts of fiber additives and cement contents. According to the results obtained from this experimental study, it was determined that MGF type new fiber additives can supply better increases in strength values in comparison with the conventional polypropylene fiber products. It was assessed that MGF type novel additives can be used to make better adherence in the CRF mixes and reinforcement performances under both compression and tension cases than those of the conventional fiber additive products.
Türkiye’nin doğusunda ilk üniversiteler 1950’li yıllarda kurulmuştur. Karadeniz Teknik Üniversite... more Türkiye’nin doğusunda ilk üniversiteler 1950’li yıllarda kurulmuştur. Karadeniz Teknik Üniversitesi (1955) ülkemizin dördüncü ve Atatürk Üniversitesi (1957) ise altıncı kurulan üniversiteleri olmuştur. Ülkenin tamamını bir bütün olarak gören ve her yerine eşit imkan sağlamak anlayışına sahip olan Mustafa Kemal Atatürk doğuda ilk üniversite açma düşüncesini 1937 yılında açıklamış ancak gerçekleştirmek için ömrü yeterli olmamıştır. Doğuda üniversite açılmasını Atatürk’ün bir vasiyeti olarak gören dönemin Cumhurbaşkanı Celal Bayar tarafından konu ile ilgili çalışmalar 1951 yılında başlatılmıştır. Bu çalışmada Trabzon ve Erzurum’da açılan doğunun ilk iki üniversitesinin kuruluş tarihçeleri incelenmiştir. Karadeniz Teknik Üniversitesi’nin kuruluş kanunun kabulü için süreç görece çok hızlı ilerlemiş olsa da eğitime başlaması için sekiz yıldan uzun bir süre beklemek durumunda kalınmıştır. Atatürk Üniversitesi ise 6 yıl süren bir çalışmanın ardından kurulabilmiş, ancak görece hızlı kalkınan bir üniversite olmayı başarmıştır. Atatürk Üniversitesi kuruluşundan hemen sonraki sene öğrenci almaya başlamıştır. Kuruluş kararı için sürecin uzamasındaki en önemli sebep şehir seçiminde yaşanan kararsızlık olmuştur. Diğer taraftan, Karadeniz bölgesinin ilk üniversitesinin açılacağı şehir konusunda tartışma yaşanmamıştır. Karadeniz Teknik Üniversitesi’nin kuruluşu Trabzon halkı tarafından talep edilmiş, bu doğrultuda milletvekili Mustafa Reşit Tarakçıoğlu önderliğinde Trabzon’da bir üniversite kuruluşunun TBMM’de görüşülmesi sağlanmıştır. Atatürk Üniversitesi’nin kurulması ise devletin en tepesinden talep edilmiş, ancak farklı şehirlerin israrları karşısında yer konusunda karar vermek kolay olmamıştır. Başta Van, Elazığ ve Diyarbakır gündemdeyken Celal Bayar ve hükümetin kararı Erzurum yönünde değişmiştir.
In this study, stress relaxation tests were carried out by keeping silt type soil specimens unde... more In this study, stress relaxation tests were carried out by keeping silt type soil specimens under different strain levels. Decreases in the stress values with time data was collected to better understand the effect of the strain level on the relaxation properties of soil specimens. In addition, the stress relaxation effect on the uniaxial compressive strength (UCS) values of the specimens was investigated with a series of tests. According to the results obtained from this study, the UCS values of the silt specimens significantly vary as a result of the stress relaxation effect. The UCS values were determined to increase with an increase of relaxation strain level to a threshold value. On the other hand, the UCS values were found to be affected adversely in case of high stress levels at the initiation of the relaxation, which are close to the peak level.
In this study, different plate fixing designs were tested in order to improve rock bolting perfor... more In this study, different plate fixing designs were tested in order to improve rock bolting performances. Instead of commonly used steel nuts, different plate fixing designs were investigated by laboratory studies. In addition, the usability of nuts and energy absorbers made of the polyamide type engineering polymer was investigated to assess whether they are advantageous for the aim of supplying high-energy absorbing features. In this experimental study, deformation-controlled load tests were carried out to evaluate the bearing and energy absorption capacities of totally eight different groups of specimens. According to the findings from this study, use of the polyamide material with steel nuts as an energy absorber material, rather than using instead of steel nuts supplies good results. As another outcome, it has been determined that use of proper washers between steel nuts and polyamide absorbers can significantly improve the energy absorption performances. It has been evaluated that the energy absorption capacity of the bolt plates can be economically increased up to 10 times by using suitable polyamide energy absorbers placed between the plate and steel nut parts. It was concluded that the polyamides can be used to remarkably improve the rock bolting performances especially in the rock masses where the high energy absorption capacity property is needed, like those with rock bursting, squeezing and swelling problems.
Blaise Pascal’ın basınç konusunda devrim niteliğindeki çalışmalarını gerçekleştirmesinde orta çağ... more Blaise Pascal’ın basınç konusunda devrim niteliğindeki çalışmalarını gerçekleştirmesinde orta çağ madencilerinin dogmatik görüşleri tetikleyici olmuştur. 17. yüzyıldaki bilimsel devrimi yapan önemli bilim adamlarından biri olarak Pascal’ın gerçekleştirdiği değerli buluşları anısına SI sisteminde basınç birimine onun ismi verilmiştir. Pascal’dan önce madenlerde su atımı 10ar metrelik kot farkları ile kademeli olarak yapılmaktaydı ve suyun pompayla bir seferde 10 metreden daha fazla yükselemeyeceği yönünde çok kalıplaşmış bir bilgi mevcuttu. Bu görüş Roma döneminden beri varolan yanlış bir bilgiydi. İlkel tulumbalarla suyun neden daha fazla yükselemediği anlaşılmamış ve bu durum ortaçağın skolastik düşünce ikliminde “su 10 metreden daha fazla yükselmekten korkar” şeklinde açıklanmıştı. Suyun daha fazla seviyelerde yükseltilebileceğini sebepleri ile açıklamış olan Pascal’ın keşifleri verimli su atımını sağlamak ve madenciliğin bilime uygun yapılması için yeni buluşlara olanak sağlamıştır. Kendi döneminden sonraki yıllarda önce buhar gücü ile sonrasında elektrikle çalışan pompaların bulunuşu onun açtığı yoldan ilerleyerek sağlanmıştır. Sanayi devrimini mümkün kılmış olan, insan gücünden makine gücüne geçiş süreci ilk olarak madenlerde su atımı amaçlı başlamıştır. Savery, Newcomen ve Watt’ın buhar makinelerini geliştirme süreçlerinin ardından 18. yüzyılda insan gücünden çok daha yüksek performansla, madenlerden görece yüksek hacimde su atımı sağlayan düzenekler geliştirimiştir. Blaise Pascal’ın getirdiği yenilikler ve bilimsel buluşları günümüzde yüzlerce metre su basma yüksekliğine sahip pompaların kullanımı için altyapı sağlamıştır. Avrupa madenlerinde yeni teknolojiler üretimin verimini artırmaktayken, sanayileşememiş ülkelerde ilkel yöntemler terkedilmemekteydi. 17. yüzyıldaki bilimsel devrimin yaşanmadığı ülkelerde sanayi devrimi de fazlasıyla gecikmiştir. Bu sebeple, maden işletmelerindeki verim konusunda ülkeler arasında fark 19. yüzyılda oldukça açılmıştı.
In this study, stress relaxation tests were carried out by keeping cement stabilized sand specime... more In this study, stress relaxation tests were carried out by keeping cement stabilized sand specimens with different particle size distributions and cement contents under various strain levels. Time-dependent decreases in the stress values were collected to better understand the effect of the strain level on the relaxation properties of the cement stabilized sand (CSS) specimens. In addition, the stress relaxation effect on the uniaxial compressive strength (UCS) values of the CSS specimens was investigated with a series of tests. According to the results obtained from this study, UCS values of the CSS specimens vary depending on the strain level during the stress relaxation. The UCS values were determined to significantly decrease in case of high-stress levels at the initiation of the relaxation, which are close to the peak value. The stress relaxation rate was measured to be rapid in the first minutes and remarkably decrease with an increase in the duration of the relaxation. Cement content was found beneficial to improve the relaxation resistivity of the CSS samples. As another outcome of this study, the fine particle content was determined to cause decreases in the strength values after the stress relaxation effect.
In this study, experimental and numerical analyses were carried out for determination of cohesion... more In this study, experimental and numerical analyses were carried out for determination of cohesion values of different types of rock materials using double shear jaws (DSJ) which can be practically used with the conventional compressive test equipment, to make shear planes in the rock core specimens. Effects of various parameters like jaw dimensions, gaps between triple blocks of the DSJ and contact conditions of the jaw on the results and validity of the cohesion test were investigated considering failure mechanisms of rock core specimens. Instead of a failure induced due to the shear stresses, tensile failures are mostly seen from conventional shear testing conditions. For a valid failure under the control of shear stresses, a DSJ design was suggested to be used in cohesion determination tests according to the results obtained from this study.
The cone bolts with expanded front ends supply improved anchoring performances and increase energ... more The cone bolts with expanded front ends supply improved anchoring performances and increase energy absorbing capacities due to ploughing in the grouted drills. Within this study, use of a novel energy absorber for the cone bolt heads were investigated to assess its design in terms of supplying high support performances. Additionally, different grout material designs were tested to investigate whether the energy absorption capacities of the rock bolts can be improved using a silicone based thermoset polymer (STP) additive. To determine load bearing and energy absorption capacities, a series of deformation controlled pull-out tests were carried out by using bolt samples grouted in rock blocks. According to the results obtained from this study, maximum load bearing capacities of cone bolts are similar and mostly depend on the steel material strength, whereas the energy absorption capacity was determined to significantly vary in accordance with the displacement limits of the shanks. As a result of using STP additive and new polyamide absorber rings, displacement limits without the steel failure increase. The STP additive was found to improve the energy absorption capacities of grouted cone bolts. The absorber rings designed within this study were also assessed to be highly effective and able to double up the energy absorption capacities of the cone bolts.
The use of the Q-slope value is a relatively new approach for the stability investigations of roc... more The use of the Q-slope value is a relatively new approach for the stability investigations of rock slopes. In this study, four different slopes in Giresun and Ordu cities of Turkey were investigated to assess whether the Q-slope approach is usable for varying slope heights, or not. A back analysis was carried out for a landslide in a case study quarry located in Kovanlik municipality of Giresun city. Carrying out detailed investigations on the geotechnical drill cores and the field studies, the Q-slope value of the rock mass of the Kovanlik quarry was determined as 0.58. According to the Q-slope approach, the slope which had a landslide under the case of 49° general slope angle and 225 m height should have been stable at a general slope angle of 59°. It has been found that the Q-slope approach is not favorable for a high slope with the height of 225 m. Two roadway excavations with steep slope angles and low heights smaller than 25 m were also investigated within this study. According to the Q-slope value, the roadway slopes which are stable for more than 3 years are estimated to be unstable. Therefore, the Q-slope approach was found also misleading for slopes with low heights like those under 25 m. On the other hand, the Q-slope method usability is confirmed obtaining parallel results with the observations from another case study slope with a height of 78 m. Although it has become a popular empirical method in the recent years, it is recommended to revise the Q-slope approach or limit its use depending on the slope height parameter.
To improve the load bearing capacities and insertion efficiency of the split set type friction bo... more To improve the load bearing capacities and insertion efficiency of the split set type friction bolts, a new apparatus has been designed and produced within this study. A series of laboratory and site studies were carried out to investigate the usability of the new apparatus. According to the results, the new apparatus was found advantageous in terms of the insertion practicality and prevention of the buckling problem. Additionally, the new apparatus was determined to increase the load bearing capacities of the bolts according to the results obtained from the pull-out test. The new apparatus decreases the friction during the bolt insertion by a temporary diametric compression of the split tubes. By allowing increases in the ratio of bolt diameter to drill hole diameter without the buckling problem during the insertion, the new apparatus supplies higher normal stresses and friction capacity at the bolt and rock contacts after opening its clamping mechanism.
Strength and deformability properties of different cavity filler materials of a phenolic foam, a ... more Strength and deformability properties of different cavity filler materials of a phenolic foam, a polyurethane based foam and a foam concrete (FC) mix were investigated and compared in this study. Instead of using polymeric foam fillers, FC usage was found to supply better load bearing capacity and modulus of elasticity values. The fresh FC mixes consisting of cement, water and foaming agents are able to be filled into the mine cavities. In the cavity filling applications, typical polymer foams cause support reactions with low stiffnesses and let the rock mass at the roof to be loosened. A relatively stiff cavity filling material can help rock masses to bear itself by prevention of the loosening. To avoid excessive deformations of the rock masses, the deformation modulus is an important parameter as well as the strength property. The FC filler materials were found advantageous because of economical supply of improved load bearing capacities and stiffness values for controlling the rock mass convergences.
In this study, effect of horizontal in situ stress on failure mechanism around underground openin... more In this study, effect of horizontal in situ stress on failure mechanism around underground openings excavated in isotropic, elastic rock zones is investigated. For estimating the plastic zone occurrence, an induced stress influence area approach (Bray Equations) was modified to define critical stress ratio according to the Mohr-Coulomb failure criterion. Results obtained from modified calculations were compared with results of some other analytical solutions for plastic zone thickness estimation and the numerical modelling (finite difference method software, FLAC2D) study. Plastic zone and its geometry around tunnels were analyzed for different in situ stress conditions. The modified equations gave similar results with those obtained from the other approaches. However, safer results were calculated using the modified equations for high in situ stress conditions and excessive ratio of horizontal to vertical in situ stresses. As the outcome of this study, the modified equations are suggested to use for estimating the plastic zone occurrence and its thickness around the tunnels with circular cross-section.
In this study, a new spring plate was designed and investigated for its usability with the split ... more In this study, a new spring plate was designed and investigated for its usability with the split set type friction bolts. According to the results of this study, remarkable active support pressures can be practically supplied by compression of the new spring plate during the insertion of the split sets. In addition to easy supply of the active support pressure owing to the insertion of the bolts, the energy absorption capacity can be highly improved by use of the new spring plate. Furthermore, the new plate design is remarkably advantageous against the nonaxial loading condition which is very wide in the bolted rock masses.
Bu çalışmada, farklı birim deformasyon seviyelerine tabi tutulan silt türü zemin numuneleri üzeri... more Bu çalışmada, farklı birim deformasyon seviyelerine tabi tutulan silt türü zemin numuneleri üzerine gerilme rahatlaması testleri gerçekleştirilmiştir. Gerilme değerlerinin zamana bağlı değişimleri ile farklı birim deformasyon değerlerinin gerilme rahatlaması üzerine etkileri incelenmiştir. Ayrıca, gerilme rahatlamasının tek eksenli sıkışma dayanımı (serbest basınç mukavemeti) değerleri üzerindeki etkileri bir dizi deneysel çalışma ile belirlenmiştir. Elde edilen bulgular, gerilme rahatlamasının tek eksenli sıkışma dayanımı (TESD) değerleri üzerinde önemli etkisi olduğunu göstermektedir. TESD değerleri belirli bir seviyeye kadar gerilme rahatlaması yaşanan birim deformasyon miktarı arttıkça yükselmiştir. Ancak, dayanım değerlerine yakın yüksek gerilme seviyelerinde başlayan rahatlamaların TESD değerlerini olumsuz etkilediği görülmüştür.
Uluslararası Mühendislik Tasarım ve Teknoloji Dergisi, 2020
Bu çalışmada polivinil asetat (PVA) reçine türü termoset polimer bağlayıcı kullanılarak silt türü... more Bu çalışmada polivinil asetat (PVA) reçine türü termoset polimer bağlayıcı kullanılarak silt türü zemin numuneleri oluşturulmuştur. Numune hazırlamadan önce elenerek sınıflandırılmış ve testlerde zemin sınıfı ML kodlu inorganik silt olarak belirlenen numune kullanılmıştır. Giresun ili merkez ilçesine ait silt numunesi farklı oranlarda (kütlece %7 ve %14) polivinil reçine ile karıştırılarak kalıplanmış ve tek eksenli basınç dayanımı değerleri belirlenmiştir. Elde edilen sonuçlara göre polivinil reçine bağlayıcı miktarı artışı ile dayanım degerleri de artmıştır. %7 ve %14 polivinil reçine içeren numunelerin dayanımları oda sıcaklığı kür koşullarında ortalama sırasıyla 0.9 MPa ve 1.6 MPa olarak belirlenmiştir. Ayrıca, farklı kür sıcaklıklarının (5°, 25°, 50°) polimerleşme üzerindeki etkileri incelenmiş ve sıcaklık artışı ile dayanım değerlerinde iyileşme olduğu belirlenmiştir. İncelenen değerler aralığında kür sıcaklığına bağlı olarak dayanımın %59 oranına kadar artış gösterdiği ölçülmüştür. PVA farklı uygulamalarda avantaj sağlayabilecek bir zemin bağlayıcısı olarak değerlendirilmiştir.
International Journal of Geosynthetics and Ground Engineering, 2020
Effect of thermoset type polymeric additives on load-bearing capacities of grouted rock bolts was... more Effect of thermoset type polymeric additives on load-bearing capacities of grouted rock bolts was investigated with both laboratory and site studies. For the specimen preparation, two different silicone-based polymeric materials were added with different amounts in the cement and water mixes. Additionally, cement grouts without the polymeric additive were also used to compare results obtained from different grout usage cases. The additives are in the liquid phase while adding into the fresh cement mix and start to solidify due to the polymerization after being mixed in the grout material. Support performances of various grouted rock bolt specimens were tested under axial and shear loading conditions. According to the results of this study, use of the polymeric additives with an amount of 3.5% by weight in total mix significantly improves the ductility in support reactions of grouted bolts and increases the energy absorption capacity by high rates over 50%.
ENGGEO’2024: National Symposium on Engineering Geology and Geotechnics, 2024
In this study, use of a new polypropylene geofiber type called microgrid fiber (MGF) was investig... more In this study, use of a new polypropylene geofiber type called microgrid fiber (MGF) was investigated in comparison with a conventional polypropylene fiber (PPF) product. California Bearing Ratio (CBR) values of a sand type soil reinforced with different polypropylene geofiber additives were investigated for different fiber ratios in soil mixes. Additionally, specimens without any fiber additive were also tested to compare their CBR values with the results obtained from the others. It was determined that both PPF and MGF additives supplied notably higher CBR values than those of the specimens with no fiber. As another outcome, MGF type fiber was found to increase the CBR values at higher rates in comparison with the conventional PPF product. It was assessed that MGF type novel geofiber additives can be used to make higher soil reinforcement performances rather than the conventional PPF products.
In this study, uniaxial compressive strength values of a sand type soil reinforced with polypropy... more In this study, uniaxial compressive strength values of a sand type soil reinforced with polypropylene fiber and silicate-based resin additives with different amounts were investigated. Microgrid fiber (MGF) was tested as a new polypropylene fiber additive in the experiments to compare it with a conventional polypropylene fiber type geosynthetic product used in soil fill improvement applications. According to the findings obtained from the uniaxial compressive strength (unconfined compressive strength) tests, it was determined that the new MGF type fiber usually increased the strength values at higher rates in comparison with the conventional fiber product. As another outcome, it was found that target strength values can be supplied by using less resin amounts for the specimens with fiber additives. It was determined that proper strength improvements can be obtained more economically by the fiber additive use together with the resin, rather than the resin added mixtures without the fiber.
International Journal of Mining, Reclamation and Environment, 2023
In this study, use of microgrid fiber (MGF) was tested as a new polypropylene fiber additive for ... more In this study, use of microgrid fiber (MGF) was tested as a new polypropylene fiber additive for cemented rock fill (CRF) mixes and compared with the conventional polypropylene fiber type geosynthetics. Changes in the uniaxial compressive strength and indirect tensile (splitting) strength values of CRF specimens were investigated for the use of different fiber types. In this experimental study, cemented basalt aggregate type rock fill materials were tested in case of using different amounts of fiber additives and cement contents. According to the results obtained from this experimental study, it was determined that MGF type new fiber additives can supply better increases in strength values in comparison with the conventional polypropylene fiber products. It was assessed that MGF type novel additives can be used to make better adherence in the CRF mixes and reinforcement performances under both compression and tension cases than those of the conventional fiber additive products.
Türkiye’nin doğusunda ilk üniversiteler 1950’li yıllarda kurulmuştur. Karadeniz Teknik Üniversite... more Türkiye’nin doğusunda ilk üniversiteler 1950’li yıllarda kurulmuştur. Karadeniz Teknik Üniversitesi (1955) ülkemizin dördüncü ve Atatürk Üniversitesi (1957) ise altıncı kurulan üniversiteleri olmuştur. Ülkenin tamamını bir bütün olarak gören ve her yerine eşit imkan sağlamak anlayışına sahip olan Mustafa Kemal Atatürk doğuda ilk üniversite açma düşüncesini 1937 yılında açıklamış ancak gerçekleştirmek için ömrü yeterli olmamıştır. Doğuda üniversite açılmasını Atatürk’ün bir vasiyeti olarak gören dönemin Cumhurbaşkanı Celal Bayar tarafından konu ile ilgili çalışmalar 1951 yılında başlatılmıştır. Bu çalışmada Trabzon ve Erzurum’da açılan doğunun ilk iki üniversitesinin kuruluş tarihçeleri incelenmiştir. Karadeniz Teknik Üniversitesi’nin kuruluş kanunun kabulü için süreç görece çok hızlı ilerlemiş olsa da eğitime başlaması için sekiz yıldan uzun bir süre beklemek durumunda kalınmıştır. Atatürk Üniversitesi ise 6 yıl süren bir çalışmanın ardından kurulabilmiş, ancak görece hızlı kalkınan bir üniversite olmayı başarmıştır. Atatürk Üniversitesi kuruluşundan hemen sonraki sene öğrenci almaya başlamıştır. Kuruluş kararı için sürecin uzamasındaki en önemli sebep şehir seçiminde yaşanan kararsızlık olmuştur. Diğer taraftan, Karadeniz bölgesinin ilk üniversitesinin açılacağı şehir konusunda tartışma yaşanmamıştır. Karadeniz Teknik Üniversitesi’nin kuruluşu Trabzon halkı tarafından talep edilmiş, bu doğrultuda milletvekili Mustafa Reşit Tarakçıoğlu önderliğinde Trabzon’da bir üniversite kuruluşunun TBMM’de görüşülmesi sağlanmıştır. Atatürk Üniversitesi’nin kurulması ise devletin en tepesinden talep edilmiş, ancak farklı şehirlerin israrları karşısında yer konusunda karar vermek kolay olmamıştır. Başta Van, Elazığ ve Diyarbakır gündemdeyken Celal Bayar ve hükümetin kararı Erzurum yönünde değişmiştir.
In this study, stress relaxation tests were carried out by keeping silt type soil specimens unde... more In this study, stress relaxation tests were carried out by keeping silt type soil specimens under different strain levels. Decreases in the stress values with time data was collected to better understand the effect of the strain level on the relaxation properties of soil specimens. In addition, the stress relaxation effect on the uniaxial compressive strength (UCS) values of the specimens was investigated with a series of tests. According to the results obtained from this study, the UCS values of the silt specimens significantly vary as a result of the stress relaxation effect. The UCS values were determined to increase with an increase of relaxation strain level to a threshold value. On the other hand, the UCS values were found to be affected adversely in case of high stress levels at the initiation of the relaxation, which are close to the peak level.
In this study, different plate fixing designs were tested in order to improve rock bolting perfor... more In this study, different plate fixing designs were tested in order to improve rock bolting performances. Instead of commonly used steel nuts, different plate fixing designs were investigated by laboratory studies. In addition, the usability of nuts and energy absorbers made of the polyamide type engineering polymer was investigated to assess whether they are advantageous for the aim of supplying high-energy absorbing features. In this experimental study, deformation-controlled load tests were carried out to evaluate the bearing and energy absorption capacities of totally eight different groups of specimens. According to the findings from this study, use of the polyamide material with steel nuts as an energy absorber material, rather than using instead of steel nuts supplies good results. As another outcome, it has been determined that use of proper washers between steel nuts and polyamide absorbers can significantly improve the energy absorption performances. It has been evaluated that the energy absorption capacity of the bolt plates can be economically increased up to 10 times by using suitable polyamide energy absorbers placed between the plate and steel nut parts. It was concluded that the polyamides can be used to remarkably improve the rock bolting performances especially in the rock masses where the high energy absorption capacity property is needed, like those with rock bursting, squeezing and swelling problems.
Blaise Pascal’ın basınç konusunda devrim niteliğindeki çalışmalarını gerçekleştirmesinde orta çağ... more Blaise Pascal’ın basınç konusunda devrim niteliğindeki çalışmalarını gerçekleştirmesinde orta çağ madencilerinin dogmatik görüşleri tetikleyici olmuştur. 17. yüzyıldaki bilimsel devrimi yapan önemli bilim adamlarından biri olarak Pascal’ın gerçekleştirdiği değerli buluşları anısına SI sisteminde basınç birimine onun ismi verilmiştir. Pascal’dan önce madenlerde su atımı 10ar metrelik kot farkları ile kademeli olarak yapılmaktaydı ve suyun pompayla bir seferde 10 metreden daha fazla yükselemeyeceği yönünde çok kalıplaşmış bir bilgi mevcuttu. Bu görüş Roma döneminden beri varolan yanlış bir bilgiydi. İlkel tulumbalarla suyun neden daha fazla yükselemediği anlaşılmamış ve bu durum ortaçağın skolastik düşünce ikliminde “su 10 metreden daha fazla yükselmekten korkar” şeklinde açıklanmıştı. Suyun daha fazla seviyelerde yükseltilebileceğini sebepleri ile açıklamış olan Pascal’ın keşifleri verimli su atımını sağlamak ve madenciliğin bilime uygun yapılması için yeni buluşlara olanak sağlamıştır. Kendi döneminden sonraki yıllarda önce buhar gücü ile sonrasında elektrikle çalışan pompaların bulunuşu onun açtığı yoldan ilerleyerek sağlanmıştır. Sanayi devrimini mümkün kılmış olan, insan gücünden makine gücüne geçiş süreci ilk olarak madenlerde su atımı amaçlı başlamıştır. Savery, Newcomen ve Watt’ın buhar makinelerini geliştirme süreçlerinin ardından 18. yüzyılda insan gücünden çok daha yüksek performansla, madenlerden görece yüksek hacimde su atımı sağlayan düzenekler geliştirimiştir. Blaise Pascal’ın getirdiği yenilikler ve bilimsel buluşları günümüzde yüzlerce metre su basma yüksekliğine sahip pompaların kullanımı için altyapı sağlamıştır. Avrupa madenlerinde yeni teknolojiler üretimin verimini artırmaktayken, sanayileşememiş ülkelerde ilkel yöntemler terkedilmemekteydi. 17. yüzyıldaki bilimsel devrimin yaşanmadığı ülkelerde sanayi devrimi de fazlasıyla gecikmiştir. Bu sebeple, maden işletmelerindeki verim konusunda ülkeler arasında fark 19. yüzyılda oldukça açılmıştı.
In this study, stress relaxation tests were carried out by keeping cement stabilized sand specime... more In this study, stress relaxation tests were carried out by keeping cement stabilized sand specimens with different particle size distributions and cement contents under various strain levels. Time-dependent decreases in the stress values were collected to better understand the effect of the strain level on the relaxation properties of the cement stabilized sand (CSS) specimens. In addition, the stress relaxation effect on the uniaxial compressive strength (UCS) values of the CSS specimens was investigated with a series of tests. According to the results obtained from this study, UCS values of the CSS specimens vary depending on the strain level during the stress relaxation. The UCS values were determined to significantly decrease in case of high-stress levels at the initiation of the relaxation, which are close to the peak value. The stress relaxation rate was measured to be rapid in the first minutes and remarkably decrease with an increase in the duration of the relaxation. Cement content was found beneficial to improve the relaxation resistivity of the CSS samples. As another outcome of this study, the fine particle content was determined to cause decreases in the strength values after the stress relaxation effect.
In this study, experimental and numerical analyses were carried out for determination of cohesion... more In this study, experimental and numerical analyses were carried out for determination of cohesion values of different types of rock materials using double shear jaws (DSJ) which can be practically used with the conventional compressive test equipment, to make shear planes in the rock core specimens. Effects of various parameters like jaw dimensions, gaps between triple blocks of the DSJ and contact conditions of the jaw on the results and validity of the cohesion test were investigated considering failure mechanisms of rock core specimens. Instead of a failure induced due to the shear stresses, tensile failures are mostly seen from conventional shear testing conditions. For a valid failure under the control of shear stresses, a DSJ design was suggested to be used in cohesion determination tests according to the results obtained from this study.
The cone bolts with expanded front ends supply improved anchoring performances and increase energ... more The cone bolts with expanded front ends supply improved anchoring performances and increase energy absorbing capacities due to ploughing in the grouted drills. Within this study, use of a novel energy absorber for the cone bolt heads were investigated to assess its design in terms of supplying high support performances. Additionally, different grout material designs were tested to investigate whether the energy absorption capacities of the rock bolts can be improved using a silicone based thermoset polymer (STP) additive. To determine load bearing and energy absorption capacities, a series of deformation controlled pull-out tests were carried out by using bolt samples grouted in rock blocks. According to the results obtained from this study, maximum load bearing capacities of cone bolts are similar and mostly depend on the steel material strength, whereas the energy absorption capacity was determined to significantly vary in accordance with the displacement limits of the shanks. As a result of using STP additive and new polyamide absorber rings, displacement limits without the steel failure increase. The STP additive was found to improve the energy absorption capacities of grouted cone bolts. The absorber rings designed within this study were also assessed to be highly effective and able to double up the energy absorption capacities of the cone bolts.
The use of the Q-slope value is a relatively new approach for the stability investigations of roc... more The use of the Q-slope value is a relatively new approach for the stability investigations of rock slopes. In this study, four different slopes in Giresun and Ordu cities of Turkey were investigated to assess whether the Q-slope approach is usable for varying slope heights, or not. A back analysis was carried out for a landslide in a case study quarry located in Kovanlik municipality of Giresun city. Carrying out detailed investigations on the geotechnical drill cores and the field studies, the Q-slope value of the rock mass of the Kovanlik quarry was determined as 0.58. According to the Q-slope approach, the slope which had a landslide under the case of 49° general slope angle and 225 m height should have been stable at a general slope angle of 59°. It has been found that the Q-slope approach is not favorable for a high slope with the height of 225 m. Two roadway excavations with steep slope angles and low heights smaller than 25 m were also investigated within this study. According to the Q-slope value, the roadway slopes which are stable for more than 3 years are estimated to be unstable. Therefore, the Q-slope approach was found also misleading for slopes with low heights like those under 25 m. On the other hand, the Q-slope method usability is confirmed obtaining parallel results with the observations from another case study slope with a height of 78 m. Although it has become a popular empirical method in the recent years, it is recommended to revise the Q-slope approach or limit its use depending on the slope height parameter.
To improve the load bearing capacities and insertion efficiency of the split set type friction bo... more To improve the load bearing capacities and insertion efficiency of the split set type friction bolts, a new apparatus has been designed and produced within this study. A series of laboratory and site studies were carried out to investigate the usability of the new apparatus. According to the results, the new apparatus was found advantageous in terms of the insertion practicality and prevention of the buckling problem. Additionally, the new apparatus was determined to increase the load bearing capacities of the bolts according to the results obtained from the pull-out test. The new apparatus decreases the friction during the bolt insertion by a temporary diametric compression of the split tubes. By allowing increases in the ratio of bolt diameter to drill hole diameter without the buckling problem during the insertion, the new apparatus supplies higher normal stresses and friction capacity at the bolt and rock contacts after opening its clamping mechanism.
Strength and deformability properties of different cavity filler materials of a phenolic foam, a ... more Strength and deformability properties of different cavity filler materials of a phenolic foam, a polyurethane based foam and a foam concrete (FC) mix were investigated and compared in this study. Instead of using polymeric foam fillers, FC usage was found to supply better load bearing capacity and modulus of elasticity values. The fresh FC mixes consisting of cement, water and foaming agents are able to be filled into the mine cavities. In the cavity filling applications, typical polymer foams cause support reactions with low stiffnesses and let the rock mass at the roof to be loosened. A relatively stiff cavity filling material can help rock masses to bear itself by prevention of the loosening. To avoid excessive deformations of the rock masses, the deformation modulus is an important parameter as well as the strength property. The FC filler materials were found advantageous because of economical supply of improved load bearing capacities and stiffness values for controlling the rock mass convergences.
In this study, effect of horizontal in situ stress on failure mechanism around underground openin... more In this study, effect of horizontal in situ stress on failure mechanism around underground openings excavated in isotropic, elastic rock zones is investigated. For estimating the plastic zone occurrence, an induced stress influence area approach (Bray Equations) was modified to define critical stress ratio according to the Mohr-Coulomb failure criterion. Results obtained from modified calculations were compared with results of some other analytical solutions for plastic zone thickness estimation and the numerical modelling (finite difference method software, FLAC2D) study. Plastic zone and its geometry around tunnels were analyzed for different in situ stress conditions. The modified equations gave similar results with those obtained from the other approaches. However, safer results were calculated using the modified equations for high in situ stress conditions and excessive ratio of horizontal to vertical in situ stresses. As the outcome of this study, the modified equations are suggested to use for estimating the plastic zone occurrence and its thickness around the tunnels with circular cross-section.
In this study, a new spring plate was designed and investigated for its usability with the split ... more In this study, a new spring plate was designed and investigated for its usability with the split set type friction bolts. According to the results of this study, remarkable active support pressures can be practically supplied by compression of the new spring plate during the insertion of the split sets. In addition to easy supply of the active support pressure owing to the insertion of the bolts, the energy absorption capacity can be highly improved by use of the new spring plate. Furthermore, the new plate design is remarkably advantageous against the nonaxial loading condition which is very wide in the bolted rock masses.
Bu çalışmada, farklı birim deformasyon seviyelerine tabi tutulan silt türü zemin numuneleri üzeri... more Bu çalışmada, farklı birim deformasyon seviyelerine tabi tutulan silt türü zemin numuneleri üzerine gerilme rahatlaması testleri gerçekleştirilmiştir. Gerilme değerlerinin zamana bağlı değişimleri ile farklı birim deformasyon değerlerinin gerilme rahatlaması üzerine etkileri incelenmiştir. Ayrıca, gerilme rahatlamasının tek eksenli sıkışma dayanımı (serbest basınç mukavemeti) değerleri üzerindeki etkileri bir dizi deneysel çalışma ile belirlenmiştir. Elde edilen bulgular, gerilme rahatlamasının tek eksenli sıkışma dayanımı (TESD) değerleri üzerinde önemli etkisi olduğunu göstermektedir. TESD değerleri belirli bir seviyeye kadar gerilme rahatlaması yaşanan birim deformasyon miktarı arttıkça yükselmiştir. Ancak, dayanım değerlerine yakın yüksek gerilme seviyelerinde başlayan rahatlamaların TESD değerlerini olumsuz etkilediği görülmüştür.
Uluslararası Mühendislik Tasarım ve Teknoloji Dergisi, 2020
Bu çalışmada polivinil asetat (PVA) reçine türü termoset polimer bağlayıcı kullanılarak silt türü... more Bu çalışmada polivinil asetat (PVA) reçine türü termoset polimer bağlayıcı kullanılarak silt türü zemin numuneleri oluşturulmuştur. Numune hazırlamadan önce elenerek sınıflandırılmış ve testlerde zemin sınıfı ML kodlu inorganik silt olarak belirlenen numune kullanılmıştır. Giresun ili merkez ilçesine ait silt numunesi farklı oranlarda (kütlece %7 ve %14) polivinil reçine ile karıştırılarak kalıplanmış ve tek eksenli basınç dayanımı değerleri belirlenmiştir. Elde edilen sonuçlara göre polivinil reçine bağlayıcı miktarı artışı ile dayanım degerleri de artmıştır. %7 ve %14 polivinil reçine içeren numunelerin dayanımları oda sıcaklığı kür koşullarında ortalama sırasıyla 0.9 MPa ve 1.6 MPa olarak belirlenmiştir. Ayrıca, farklı kür sıcaklıklarının (5°, 25°, 50°) polimerleşme üzerindeki etkileri incelenmiş ve sıcaklık artışı ile dayanım değerlerinde iyileşme olduğu belirlenmiştir. İncelenen değerler aralığında kür sıcaklığına bağlı olarak dayanımın %59 oranına kadar artış gösterdiği ölçülmüştür. PVA farklı uygulamalarda avantaj sağlayabilecek bir zemin bağlayıcısı olarak değerlendirilmiştir.
International Journal of Geosynthetics and Ground Engineering, 2020
Effect of thermoset type polymeric additives on load-bearing capacities of grouted rock bolts was... more Effect of thermoset type polymeric additives on load-bearing capacities of grouted rock bolts was investigated with both laboratory and site studies. For the specimen preparation, two different silicone-based polymeric materials were added with different amounts in the cement and water mixes. Additionally, cement grouts without the polymeric additive were also used to compare results obtained from different grout usage cases. The additives are in the liquid phase while adding into the fresh cement mix and start to solidify due to the polymerization after being mixed in the grout material. Support performances of various grouted rock bolt specimens were tested under axial and shear loading conditions. According to the results of this study, use of the polymeric additives with an amount of 3.5% by weight in total mix significantly improves the ductility in support reactions of grouted bolts and increases the energy absorption capacity by high rates over 50%.
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Papers by Eren Komurlu
rock mass of the Kovanlik quarry was determined as 0.58. According to the Q-slope approach, the slope which had a landslide under the case of 49° general slope angle and 225 m height should have been stable at a general slope angle of 59°. It has been found that the Q-slope approach
is not favorable for a high slope with the height of 225 m. Two roadway excavations with steep slope angles and low heights smaller than 25 m were also investigated within this study. According to the Q-slope value, the roadway slopes which are stable for more than 3 years are estimated to be unstable. Therefore, the Q-slope approach was found also misleading for slopes with low heights like those under 25 m. On the other hand, the Q-slope method usability is confirmed obtaining parallel results with the observations from another case study slope with a height
of 78 m. Although it has become a popular empirical method in the recent years, it is recommended to revise the Q-slope approach or limit its use depending on the slope height parameter.
rock mass of the Kovanlik quarry was determined as 0.58. According to the Q-slope approach, the slope which had a landslide under the case of 49° general slope angle and 225 m height should have been stable at a general slope angle of 59°. It has been found that the Q-slope approach
is not favorable for a high slope with the height of 225 m. Two roadway excavations with steep slope angles and low heights smaller than 25 m were also investigated within this study. According to the Q-slope value, the roadway slopes which are stable for more than 3 years are estimated to be unstable. Therefore, the Q-slope approach was found also misleading for slopes with low heights like those under 25 m. On the other hand, the Q-slope method usability is confirmed obtaining parallel results with the observations from another case study slope with a height
of 78 m. Although it has become a popular empirical method in the recent years, it is recommended to revise the Q-slope approach or limit its use depending on the slope height parameter.