SPT-N’ den Hesaplanan Zeminin Kayma Dalgası (Vs)’nın Eskişehir Zemini için İstatistiksel Olarak Değerlendirilmesi

Kayma dalgası hızı (Vs) geoteknik mühendisliği problemlerinin belirlenmesi çalışmalarında önemli parametrelerden biridir. Dinamik saha sınıflandırmasında yüzeyden ilk 30 metre derinlik için kayma dalgası hızı önemlidir. Bu nedenle kayma dalgası hızı (Vs)30 ve SPT-N değeri zemin davranışı, zemin-yapı etkileşimi gibi deprem mühendisliği çalışmaları için gereklidir. Zeminin kayma dalgası hızı arazide sismik kırılma ve kuyu içi sismiği gibi sismik yöntemler kullanılarak belirlenebilmektedir. Ancak bu yöntemler büyük iş gücü gerektiren, zaman alıcı ve ekonomik olmayan yöntemlerdir. Bu nedenle birçok çalışmada SPT-N sayısına bağlı olarak Vs hesabı yapılan ampirik yaklaşımlar kullanılmaktadır. Ancak, bu yaklaşımlar farklı çalışma alanlarında yapılmıştır. Zemin koşullarının farklılık göstermesi nedeniyle bu yaklaşımların Eskişehir zemini için doğruluğunun belirlenmesi gerekmektedir. Bu çalışmada Eskişehir’de arazi çalışmaları kapsamında sismik yöntemler kullanılarak belirlenen gerçek Vs değerleri ile Eskişehir zemini temsil eden sondajlardan elde edilen SPT-N değerlerinden hesaplanan Vs değerlerinin karşılaştırılması yapılmıştır. Sonuç olarak en uygun olan yöntem istatistiksel olarak belirlenmiştir

Transient analysis with MODFLOW for developing water-diversion function

The management of urban channel systems constitutes an important problem in most developing cities of the world. In this study, a deterministic approach was followed to obtain water-diversion function through development of a numerical model that includes main hydrological elements such as stream flow, groundwater flow with stream-aquifer interaction, and evapotranspiration. An application to the city of Eskisehir (Turkey) is presented. The city has an extending channel network lying on an alluvium plain. In developing the new diversion function, three main criteria were taken into consideration: (1) the conservation of ecosystem; (2) flood prevention; and (3) aquifer replenishment. As the aquifer is the main water resource in the basin, a total of 96 boreholes were drilled in the framework of two projects. From these borehole data, stratigraphy and the piezometric head distribution were obtained. The basin was modeled using MODFLOW under Ground-water Modeling System (GMS) software. For calibration of hydraulic conductivities, the parameter estimation model was used. Through steady-state analysis, flood-prone areas were determined. Transient simulations were performed over a period of 650 days covering both low and high flows. A computer code following an iterative procedure was written in order to integrate the diversion function into MODFLOW. Simulation results demonstrated that the proposed function was successful in satisfying all three criteria

The 2011 Earthquake in Simav, Turkey and Seismic Damage to Reinforced Concrete Buildings

Reinforced concrete buildings suffered significant damage in the region affected by the 29 May 2011 earthquake in Simav (Kutahya), Turkey. Typical building damage is classified and potential causes of damage are investigated. Reinforced concrete moment resisting frames with hollow brick infill walls are the most common structural system in and around the Simav city center while masonry construction is common in rural areas. Although the Simav earthquake, with a magnitude of 5.7 to 5.9, can be classified as a moderate earthquake, many buildings experienced damage varying from frequent diagonal cracking and brittle failure of infill walls to collapse or severe damage to frames due to short columns, soft stories or other reasons including insufficient or poor detailing of reinforcement. This study investigates and presents the seismicity of the region, characteristics of the measured ground motions, seismic load demands including response spectra, and damage mechanisms, potential causes and classification of observed damage in reinforced concrete buildings

Mechanical Properties of Cement Mortar Containing Heat-Treated Boron Derivative Waste at Elevated Temperatures

The largest boron reserves in the world are located in Turkey. The production of boron compounds and use of generated boron derivative waste during this production are extremely important for both economically and environmentally. This study evaluates boron derivative waste and investigates doping effects of heat-treated boron derivative wastes on mineralogical, microstructural, and mechanical properties of cement mortar. The waste, portland cement, and wastes heat-treated at temperatures of 400-900 degrees C are characterized. The cement is partially replaced with heat-treated wastes at 800 and 900 degrees C in weight ratios of 15, 25, and 35%. Compression tests are conducted for all mortars and proximate strength value to reference mortar is obtained with the incorporation of waste heat-treated at 800 degrees C by the 25% ratio. From a strength point of view, thermally processed waste is practical for use in the production of cement mortar at 25% by weight

Assessment of the Fundamental Resonance Frequency of the Sedimentary Cover in the Eskisehir Basin (Turkey) Using Noise Measuremeets

Geological observations indicate that the Eskisehir graben is related with Eskisehir Fault Zone (EFZ), one of the major active structures within the Anatolian plate. The fault zone has a considerable seismic risk for the urban area of Eski¸sehir. Local site conditions substantially affect the characteristics of seismic waves and generally have a direct effect on the potential of the earthquake damage. Site effects are very complex factors. The importance of site response is well known, and few would question the assertion that the motion on soil is usually greater than on rock, when all other things were being held equal. In general, site response estimation can be obtained from instrumental recordings. The purpose of this study was to estimate if there would be a relationship between the structural geology in the Eskisehir Basin and the fundamental resonance frequency. Extensive ambient noise measurements were performed in the basin of Eskisehir from June 2010 to spring 2012. In this work, we conduct microtremor surveys to investigate the 3-D basin structure of Eskisehir Basin and determine the fundamental resonance frequency of the sedimentary cover in the Eskisehir Valley area. The measurements of single-station microtremor were carried out at 318 sites in the Eski¸sehir Basin. We use data recorded by a broadband seismometer and digitizer CMG-6TD, Guralp seismometer. Some of the measurement locations, the CMG-6TD sensor was located into 30 cm-deep holes in the ground to avoid strongly wind-generated, long-period noise. Finally, a map showing the fundamental resonance frequency distribution in the studied area was drawn using the results obtained from applying the HVSR technique. A fundamental resonance frequency map of the Eskisehir Basin was produced from main peak in the horizontal-to-vertical component (H/V) spectral rati

Utilization of Waste Clay from Boron Production in Bituminous Geosynthetic Barrier (GBR-B) Production as Landfill Liner

Bituminous geomembranes, one type of geosynthetics, include a hot bituminous mixture with mineral filler and reinforcement. In this study, boron production waste clay (CW) was used as filler to produce a geosynthetic barrier with bentonite, waste tire, and bitumen. Bentonite and waste tires were used as auxiliary fillers and bitumen as the binder. CW/bitumen, CW/bentonite/bitumen, and CW/waste tire/bitumen mixtures were prepared by using a laboratory mixer at 100°C. Hot mixtures were extruded into strips by using a lab-scale corotating twin screw extruder (L/D: 40) followed by die casting (2 mm × 100 mm). Glass fleece or nonwoven polyester was used as reinforcement material and while die casting, both sides of the reinforcement materials were covered with bituminous mixture. Thickness, mass per unit area, tensile strength, elongation at yield, and hydraulic conductivity were used to characterize the geomembranes. Among all geomembranes, nonwoven polyester covered with 30% bitumen-70% boron waste clay mixture (PK-BTM30CW70) was found to be the most promising in terms of structure and mechanical behaviour. After that, consequences of its exposure to distilled water (DW), municipal solid waste landfill leachate (L-MSW), and hazardous waste landfill leachate (L-HW) were examined to use for an innovative impermeable liner on solid waste landfills

DAG: Atmosferik ve Astronomik Gözlem Sistemleri

DAG Projesi kapsamında; gözlemevi yerleşkesine kurulmuş ve kurulacak olan sürekli ölçüm yapan ve yapacak olan atmosferik ve astronomik sistemlerin (AWOS, Davis, Boltwood, ASC, SM, SQM, MASS-DIMM, vb) tanıtımı, teknik özellikleri ve örnek veri setlerinden örnekler sunulacaktır. Bir gözlemevinde olması gereken bütün sistemlerin birlikte oluşturduğu sistemin ayrıntılı tanıtımı yapılacaktır