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The SPE Turkey Section supports four SPE student chapters--the Middle East Technical University (METU) Chapter; Middle East Technical University–Cyprus Chapter; Istanbul Technical University (ITU) Chapter; and Batman University Chapter--and works to connect each chapter and its instructors with each of the other three chapters and their instructors. One of the most exciting seminars took place at the METU Petroleum and Natural Gas Engineering (PNGE) Department auditorium on 25 March 2014 in Ankara. The title of the discussion was "Thoughts on Petroleum Engineering Education and Industry–University Collaboration." Mustafa Onur, a professor at ITU who has developed and taught courses at both the undergraduate and graduate levels at four universities--University of Tulsa, ITU, Universiti Teknologi Petronas, and King Saud University--was the presenter. The discussion drew about 100 attendees, including 10 instructors from PNGE departments, high-level executives, and students from the METU and ITU student chapters.
Abstract Tunnel 5 was constructed within the scope of Ankara-Sivas High Speed Railway Project conducted by General Directorate of Turkish State Railways. A collapse in the tunnel and deformations on the surface occurred at around at Km:319+038 during the excavation works of Tunnel 5 (Km:318+070-Km:319+150). The distance between exit portal section and the collapse location was approximately 30 m, some fractures and some slides were observed at the portal section. In the present study, the mechanism of the collapse in the tunnel and the stability of the portal section are presented and discussed. In addition, the support systems were proposed to provide safety and to eliminate the problems sourced from the collapse. Within the purpose of the study, the numerical analyses were performed via Phase2D software and in turn the results were discussed. Eventually, for portal stability the adequate measures are proposed. 1 Introduction Within the scope of "Ankara-Sivas High Speed Railway Project, Infrastructure Supply Construction Section 1 (Km: 282 + 600-332 + 300) Between Yerköy-Yozgat-Sivas", which was gone out to tender by Republic of Turkey General Directorate of State Railways Department, excavation and tunnel support works of T5 Tunnel (Km: 318 + 070 - 319 + 150) has been progressing when there was a collapse reaching to the surface occurred on 04.11.2014 at Km:319+038.20. Consequently, various deformations were observed on the support systems at the portal location. The collapse inside the tunnel and the relevant settlements on the surface lead to the deformations, in macro scale, at the 49.2 m section located between Km: 319 + 085,00 – 319 + 035,80 which was designed according to C3 rock support class, and at the surface of the portal areas. As a result of these deformations, tunnel excavation works were stopped. Fig. 1 shows the collapse on the tunnel and the cracks on the portal while the general view from the outlet portal is seen in Fig. 2.
ABSTRACT: This paper presents part of the slope stability improvement program carried out at Kışladağ Gold Mine in Turkey. A slope stability project was initiated at the site recently to review the minor slope failures as well as the geotechnical and final wall design aspects in detail. Two minor slope failures occurred in December 2014 at the north-east section of the pit in spite of the high quality slope stability implementations at Kışladağ Mine. The work presented in this paper showed that changes to the blasting and geotechnical parameters are required at the north-east section of the pit. Geotechnical design changes were 10 m bench heights with 70° slope face angle at that specific area. Having implemented several geotechnical and blast design changes, the followings were observed in the pit: reduced crest loss, reduced number of minor slope failures and more visible half barrels in friable rock types. 1 INTRODUCTION Kışladağ Mine is the largest gold mine in Turkey. It is operated by Tüprag Metal Madencilik which is a subsidiary of Eldorado Gold Corporation. The mine site is located in southwest of Usak, west-central Turkey between major cities Ankara and Izmir (Fig. 1). To date, detailed geotechnical data collection and evaluation studies as well as stability assessments have been carried out at the Kışladağ Gold Mine. The onsite geotechnical studies involved the following studies and methods:data collection and evaluation (geotechnical drilling of boreholes, scan line and window mapping surveys, geotechnical logging from oriented cores, rock mass classification, geotechnical characterization of the slope forming materials, pit dewatering and slope depressurization studies etc.); slope movement monitoring (manual surveying of prisms, slope monitoring radars (Reutech Mining 2016), visual inspections and wireline extensometers); slope performance evaluations (monthly berm and bench inspections, preparation of rock failure reports and open pit hazard map); and slope stability analyses (the use of different methods to assess the stability of the benches, berms and overall slopes under different conditions). This paper summarizes the recent geotechnical works and assessments which were combined with the final wall blasting project carried out on-site.
Abstract: Four-point asymmetric bending beam geometry can conveniently be used in shear mode fracture testing of rock and concrete-like materials. Stress intensity factors are computed by contour integration procedure embedded in a finite element program package. To achieve pure shear mode state, loading configuration and parameters are varied in models of rectangular beams. Beam depth is varied as 40, 50, and 60 millimeters. Initial crack length/beam depth ratio (a/W) is varied between 0.15 and 0.60. Pure shear conditions at crack are generated by changing asymmetric loading spans at upper and lower boundaries of the beam geometry. Computations showed that as beam depth was increased, mode II stress intensity factor decreased. Mathematical relations for pure shear mode stress intensity factor were proposed with varying asymmetric loading span and a/W to assure pure shear mode state at crack front. Proper loading and beam geometric conditions were identified for pure mode II fracture toughness KIIc testing. From four-point asymmetric bending tests on Ankara andesite, average mode II fracture toughness value was found as 0.61 MPavm. Results of shear mode fracture toughness tests showed that variation of beam depth had no significant effect on mode II fracture toughness of beam type rock specimens. Introduction Shear type (mode II) loading state is still an active subject of interest in fracture mechanics. Although, numerous test methods have been suggested (Rao et al., 2003, Awaji and Sato, 1978, Atkinson, 1982, Fowell and Xu, 1993)[1-4] to measure mode II fracture toughness KIIc of rocks, common opinion in this respect is not well-established yet. Mode II fracture toughness tests aim to measure resistance of a crack to propagate due to in plane shear stress acting on it. Mode II fracture toughness of rocks appears in practical problems of rock mechanics such as hydraulic fracturing (Daneshy, 1974, Hubbert and Willis, 1957), rock cutting (Hood and Roxborough, 1992, Xu, 1993), and rock burst mechanism investigations (Salamon 1963, Cook 1965, Zipf and Heasley, 1990). In geotechnical applications, rock medium is usually under the effect of compressive forces as a result of overburden stress. This increases the importance of shear mode crack formation and propagation under pure shear mode or under mixed mode loading involving compressive-shear state over the crack.
Abstract It is vital to understand the stability fields of rock masses of recent engineering structures in Turkey (e.g., high-speed railway tunnel system) before their safely construction. This research project investigates rock mass stability of Ankara-Elmadag tunnel – extending 2975 m, covering 12.5m diameter space, within a sectional on the high-speed railway system between Ankara and Sivas. Based on our field orientied geological work, we identified two rock formations in the complex geologic setting, proximal to the Ankara ophiolitic Melange. Stratigraphically, Triassic age metasandstone-siltsone (Elmadağ formation) was thrusted over the Serpentinites, Cretaceous (Artova formation). In addition to this, rock mechanical parameters based on laboratory studies are received from TCDD (Turkish State Railways). The data derived from these studies are combined to evaluate the rock mass characaterization, quality and strength to determine the engineering behaviours of the rock masses in the region where tunnel will be constructed. 1. Introduction Elmadag tunnel (T11) is designed to be constructed between Ankara-Sivas railway system in Elmadag, Central Turkey. The study area is located 41 km in the east of Ankara city center. The length and diameter of this tunnel will be 2975m and 12.5 m, respectively. Previous geological overview by Akyurek et al. (1984) suggests that the region is located in the complex setting of Ankara mélange. According to authors, two rock formations in the study area are identified, namely they are Elmadag formation (metasandstone- siltstone Triassic age) thrusted over the Artova formation (Serpentinites, Cretaceous). Due to the highly deformed characteristics of these rocks, the prediction of engineering problems before construction is essential. For this purpose, data from laboratory tests and drilling logs (received from TCDD) are combined to determine engineering parameters of rock masses in the excavation area. The results of the uniaxial compressive strength tests do not represent the field conditions, thus the strengths of rock masses are predicted through Hoek-Brown (Hoek et al., 2002) empirical equations. Additionally, numerical analyses are performed to estimate total displacements (deformations) in the excavated region and potentially predict unstable parts of tunnel.
Abstract In recent years, many tunnel projects were carried out and will go on to create alternative ways of transportation as well as shorten the distance driven in parallel with the increasing population and number of vehicles also to achieve savings from time, energy, fuel, etc. In drill and blast method in tunneling (railway tunnels, road tunnels, pedestrian tunnels, subway tunnels, sewer tunnels, diversion tunnels, etc.) drilling constitutes the largest cost and time. Choosing the wrong bit and wrong operating parameter causes cost increase and delays in the work plan. Drilling performance of Atlas Copco Rocket Boomer 282 Jumbo Driller was examined in this study that was used in Altan Ayağ Tunnel (T3 Tunnel) Located in Antalya-Kemer-Tekirova Highway. The physical and mechanical properties of the rocks where the drilling machine was running were determined both in the field and laboratory tests. Drilling machine was run with 3 different types of bits. Time studies were carried out for each drilling bit's penetration rate. Drilling machine parameters (rotation, thrust force, flushing etc.) were kept constant during drilling. Level of the noise caused by drilling was measured by audiometer. As a result, considering the penetration rates of each bits used in drilling operations and suitable bit type was determined for the rocks where the drilling machine was running. Also, the noise levels depending on the bit type were examined by comparing. 1. Introduction In modern tunnel and underground cavern excavations, it is easy to select from many different excavation methods. The method of drilling and blasting has been used for excavation of underground spaces in rock for a long time in tunnels, rock caverns and mines. The major part of underground excavation is drill and blast (NTS, 2004). In drill and blast method in tunneling drilling constitutes the largest cost and time. In order to reduce the cost, the selection of the most appropriate bit according to formation is very important. Choosing the wrong bit and wrong operating parameter causes cost increase and delays in the work plan. The most widely researched parameter is compressive strength in analyses of tunneling and drilling operations. Paone & Madson (1966), Paone et al. (1969a, b), Barendsen (1970), Brown & Phillips (1977), Hughes (1986), Karpuz et al. (1990), Kahraman (1999) investigated the relationship between penetration rate and the various rock properties. Thuro (2002) and Plinninger (2002) researched the performance of the drilling machines and wear mechanisms of the drilling bits on intact rocks. Kahraman et al. (2006) examined the performance of a drilling machine in Ankara-Pozanti Highway tunnel. Controllable parameters (rotational speed, thrust, blow frequency and flushing) and uncontrollable parameters (rock properties and geological conditions) affect the rock drillability (Kahraman, 2003). The main parameters of rocks that affect drillability are given in Table 1.
Ertin, A. (Istanbul University) | Gicir, A. (Turkish State Railways (TCDD)) | Yazici, I. F. (CRCC-CMC-Cengiz-IC Ictas Consortium) | Sahin, T. (CRCC-CMC-Cengiz-IC Ictas Consortium) | Posluk, E. (Turkish State Railways (TCDD)) | Babal, M. (Turkish State Railways (TCDD))
Abstract: The aim of Ankara – İstanbul High-Speed Railway Project is to decrease the travel time between Ankara and İstanbul and to generally provide a faster, more comfortable and safer journey experience. The construction of the second Phase which is İnönü – Köseköy line section already started on September 2008. The geomorpho-logical and geological conditions on this 158 km section are among the roughest across the country. To give an idea, there are 33 tunnels with a total length of 55 km and 27 viaducts with a total length of 15 km. Excavation of Tunnel No.26 in this second phase started on October 2009 by us-ing NATM method. The first 297meters of the tunnel were completed with a rate of 2 m/day in chlorite and graphitic schists. It was found that a total length of 5195 meters of tunnel no.26, boring from both inlet and outlet portals can be completed within 1500 days with the same geological conditions. The estimated time is more than the required and also increases the total cost. For this reason it is realised that continuing the excavation with a tunnel boring machine (TBM) would be the optimum solution. On 1st of June a TBM with a diameter of 13,77 m. started to fix the already excavated first 297 meters. Hypothetically, the tunnel face is expected to be reached in mid Sep. 2011. In the light of additional geological and geotechnical investigations, the answers of the low penetration rate boring with NATM method tried to be highlighted and the performance of the TBM is estimated by QTBM method. By using this method the penetration rate is calculated as 8,35 m/hr and the advance rate is calculated as 0,75 m/hr for the 13,77 meter tunnel boring machine driving in chlorite and mica schists.
Ogul, K. (TCDD) | Gicir, A. (TCDD) | Topal, I. (Dumlupinar University) | Aksoy, C. O. (Dokuz Eylul University) | Posluk, E. A. (Istanbul University) | Aldas, G. U. (Ankara University) | Ozer, S. C. (Istanbul Technical University)
Abstract: Ankara – Istanbul high speed railway construction project consists of 32 tunnels. Tunnel 36 is one of these tunnels and water problem encountered during the excavation of this tunnel is studied in this paper. Total length of that tunnel, which is excavated with NATM, is 4096 meters and located between km 239+934,00 and km: 244+030,80. Tunnel is excavated in Porsuk Miocene Formation (sandstone, clay stone, gravel alternation) and Akpinar Formation (limestone-sandy limestone) which have same ages. Excavations started in the tunnel entrance portal in Porsuk Formation and water inflow has happened while passing Akpinar Formation with dip slip fault at km.241+003,80. Water inflow had negative impact on the units of initial support system and it caused deformations in the lipper-bench especially at the locations where construction hadn't been finished. Deformations at these locations are occurred in this form; softening of the formations, which carry the footplates, with the effect of water inflow thus, formations couldn't carry the loads on them and settlements occur. In this study, the problems caused by underground water in the tunnels and solution methods are discussed. 1 INTRODUCTION Groundwater infiltration into tunnels can pose a serious risk during the execution of works and reduce the speed of excavation. The presence of water in a rock massif can induce some difficulties and increase the cost of excavation (Jansson, 1979; Cesano et al., 2000; Day, 2004). Furthermore, the drawdown produced by excavations can cause hydrological, hydrogeological and environmental impacts on groundwater dependent ecosystems (Vincenzi et al., 2009). Among the common hydrogeological impacts in densely populated areas are the drying of private wells or springs close to the tunnel axis due to the water table drawdown (Sjolander-Lindqvist, 2005) and base flow reduction in rivers that drain the basins crossed by the tunnel (Vincenzi et al., 2009).
Abstract Groundwater problem in Bolu tunnel has been studied. An analytical modeling using the conformal mapping technique has been developed. Bolu tunnel for the motorway between Ankara— Istanbul aligns through the north Anatolians fault zone and trust zones. The related rock units and the topography of region are given. The hydraulic heads, generally varying in accordance with topography are given. The water discharge at a certain point of the tunnel is calculated. Where, the rocks are considered to have hydraulic conductivities between 10 and 10 msec. But, at some points water drainage reduces the water heads. The analytical solution is original. The data i.e. hydraulic conductivity, hydraulic head is inserted into this solution. The discharge obtained by calculation is compared to the case with circular shape. It has been found that the developed analytical model is a tool for the estimation of the water inflow.
Kulaksiz, S. (Hacettepe University Department of Mining Engineering Beytepe-Ankara) | Bayram, F. (Hacettepe University Department of Mining Engineering Beytepe) | Yasitli, N.E. (Hacettepe University Department of Mining Engineering Beytepe) | Yilmazkaya, E. (Hacettepe University Department of Mining Engineering Beytepe)
ABSTRACT Metamorphosed carbonate bearing rocks contain mainly calcite, dolomite and secondary minerals which are their Mohs scale hardness over five. These minerals depend on chemical compositions of rocks, pressure and temperature condition of metamorphism are developed such as diopside, tremolite, actinolite, garnet, epidote, wollastonite, amphiboles. These secondary mineral assemblages have contents % 10 and % 30 in calc-silicate marbles. These minerals assemblages hardness change 5–7.5, abrasiveness specifications and minerals boundary conditions (textures) showing different variety. These conditions exhibit some problems production of marble slabs. Mineral composition of calc-silicatic marble used in this study is calcite, ±garnet, diopside, ±quartz, wollastonite. The percentages of minerals are 60–70 % calcite, 28–35 % wollastonite, 1–4 % diopside, 0–3 % quartz, 0–0.5 % garnet. The sawing problems of calc-silicate marbles during sawing with circular saws were realized. I. Introduction Calc-silicate Kaman-Kırşehir marble deposits location is 170 km far from Ankara-Tuerkiye (Figure 1). Calc-silicate marble deposit is massive apparent schistose structure covers about 4 km by 1 km of regionally metamorphosed sedimentary limestones. The thickness of deposit about 100 m is indicated. The strike of bed is NW-SE direction and dip angle changes 10°-30° NE and SW (Figure 2). The industrial rock can be evaluated as wollastonite deposit [1,2]. The main problem is extreme wearing of circular saw blade segments during the cutting of marble. The subject of research is the assessment and minimizes the wearing of saw blade in this marble. After mineralogical and petrographical investigations, sawing operations on this rock were performed. Firstly, suitable sawing conditions (saw blade peripheral speed and advance rate) were determined by sawing tests. Then sawing operations were realized at determined sawing conditions. According to results, the sawing problems of calc-silicate marbles were evaluated. 2. Mineralogy and Petrography ofDeposit The rock is white and light colored green. The thickness of wollastonite band is 1%3 cm and calcite band is 3%10 cm (Figure 3). Tamadağ Formation calc-silicate rocks mineral contents determined by microscope: - Diopside + Wollastonite ± Garnet ± Quartz + Calcite - Wollastonite + Quartz - Tremolite + Diopside + Wollastonite + Calcite The mineral composition of this metacarbonate rock changes to calcite or wollastonite band structure. Therefore mineral percentage also changes to this conditions. Microscopic thin section studies of these rocks do not representative because of very small area taking into consideration. Instead of this it is decided to use image analysis technique for determining of mineral composition percent (%). The rock sample was cut to 20 cm by 20 cm or 20 cm by 30 cm and 1 cm thick slabs. These slab surfaces were polished and have taken the pictures by a digital camera. Then, the images of slabs were adopted to CLEMEX Vision PE 3.5 software . Calcite-wollastonite color index problem is solved by calcite staining (Figure 4). The mineral percentages of Kaman calc-silicate marble were determined by Clemex Vision software and were given in Table 1.