Freeze-thaw performance of chemically stabilized natural and recycled highway materials     

Tuncer B. Edil  Bora Cetin 《寒旱区科学》2015,7(5):482-491

This article provides an overview of several previous studies that investigated the stiffness and strength performance of chemically stabilized roadway materials under winter conditions (freeze-thaw cycling). The objective of this research was to understand the behavior of different materials stabilized with different type of binders when they were subjected to freeze-thaw cycling. Nine different materials including natural soils (organic soil, clay, silt, sand, and road surface gravel), reclaimed pavement material, and recycled asphalt pavement stabilized with nine different binders (five different fly ashes, lime, cement, lime kiln dust, cement kiln dust) were discussed. This article investigated how the volume, resilient modulus and unconfined compressive strength of soils/materials stabilized with different binders change in response to freeze-thaw cycling. Overall, the review results indicate that the stiffness and strength of all stabilized materials decrease somewhat with freeze-thaw cycling. However, the reduced strength and stiffness of stabilized materials after freeze-thaw cycling was still higher than that of unstabilized-unfrozen original soils and materials. In addition, materials stabilized with cement kiln dust provided the best performance against freeze-thaw cycling.  相似文献   

An Extended Approach of Particle Swarm Optimization for Shoreline Extraction from RASAT Imagery     

Hatice Catal Reis  Bülent Bayram  Salih Bozkurt  Abdulkadir Ince  Nusret Demir  Dursun Zafer Seker 《Journal of the Indian Society of Remote Sensing》2018,46(8):1223-1232

This study presents an extended shoreline detection approach from pansharpened images of Turkish RASAT satellite which covers red, green and blue bands of the optical spectrum with 15 m ground resolution and panchromatic band with 7.5 m spatial resolution. The Lake Ercek of Turkey has been selected as the study area, which is a tectonic lake and home to a variety of water birds. The satellite images of the lake taken in 2013 and 2014 were considered for analysis. The proposed shoreline extraction system consists of a sequence of image processing steps in which simple linear clustering (SLIC) and particle swarm optimization (PSO) are the main components. SLIC was used to create superpixels that form basis for object-based image analysis while PSO was employed for classifying objects into corresponding classes. The resulting images still contained unwanted artefacts; therefore, a post-processing step was performed to improve the accuracy of segmentation by applying thresholding, morphological processing, and manual editing for noise removal. The proposed framework was applied on two temporal RASAT images to test the variations of defined parameter settings. The success of the proposed system was to obtain shorelines with satisfying accuracy without using NIR band. Finally, the extracted shorelines were vectorised and compared with manually digitized shorelines from pansharpened satellite images for accuracy assessment.  相似文献   

Effect of shear strain compatibility and incompatibility approaches in the design of high modulus columns against liquefaction: A case study in Christchurch,New Zealand     

Demir  Selçuk  Özener  Pelin 《Bulletin of Earthquake Engineering》2022,20(11):5721-5745

Bulletin of Earthquake Engineering - Nowadays, investigating the effectiveness of high modulus columns in liquefaction mitigation is one of the important tasks in earthquake geotechnical...  相似文献   

Field Evaluation of Ultrasonic Method for Assessing Well Seals     

Nazli Yesiller  Craig H. Benson  Tuncer B. Edil 《Ground Water Monitoring & Remediation》1997,17(3):169-176

Field tests were conducted in three boreholes using an ultrasonic testing method to evaluate its ability to assess contact between the seal and riser (casing). The ultrasonic method is used inside the riser without disturbing the riser, seal, or formation soil. The risers were 50-mm-diameter (2-inch) Schedule 40 steel pipes that are used for ground water monitoring wells. Different types of seals were placed around the risers and defects were purposely introduced in the seals to test the ultrasonic method. The ultrasonic response changed as the neat-cement seals cured or hydration of the bentonite seals changed. When adequate moisture was not available, the bentonite seals deteriorated, losing contact with the riser. When adequate moisture was available, however, the seals swelled into contact with the riser. Both conditions were detected with the ultrasonic method. The method also detected the intentional defects, as well as defects that were not intended. The boreholes were excavated to compare results of the ultrasonic tests with the actual condition of the seals. The condition of the seals agreed well with the results of the ultrasonic tests.  相似文献   

The effects of dodecylamine, kerosene and pH on batch flotation of Turkey's Tuncbilek coal     

S. Kelebek  U. Demir  O. Sahbaz  A. Ucar  M. Cinar  C. Karaguzel  B. Oteyaka 《International Journal of Mineral Processing》2008,88(3-4):65-71

The effects of dodecylamine (DDA), kerosene and pH on the recovery of combustible matter and ash content of a lignitic coal from Tuncbilek, Turkey have been studied using a three-variable and two-level (2³) factorial experimental design. The coal sample responded favourably to batch flotation with high recoveries in excess of 95% using both kerosene and DDA respectively. The main effects of all three factors on the recovery are positive. Significance of DDA as a collector, is somewhat greater than that of kerosene, but its selectivity for ash reduction is not significant at the 95% confidence level. The pH-dependence of recovery by these collectors is opposite to each other. The DDA-induced flotation recovery is lowest at pH 9.4, an effect which has been related to precipitation of cationic species of this collector. The kerosene-induced recovery and grade of combustible matter increases with pH and this has been attributed to a better dispersion of coal and its associated clays. The two-way interaction effects are all negative at a smaller level. The main and interaction effects have been discussed on the basis of adsorption at most favourable surface sites, different modes of orientation of DDA species, competition with kerosene, and probable collecting properties of the frother used. The simultaneous effects of the two collectors on the recovery of combustible matter have been discussed at each pH value used.  相似文献   

Landfill Leachate Treatment: A Case Study for Istanbul City     

Cevat Yaman  Huseyin Kurtulus Ozcan  Goksel Demir  Hatice Eser Okten  Senol Yildiz  Asli Coban  Vahit Balahorli 《洁净——土壤、空气、水》2012,40(7):706-711

One of the most important problems arising from landfilling solid wastes is the leachate which contains high amount of pollution. Discharge of leachate without treatment causes negative effects on environmental and public health. In this study, parameters of chemical oxygen demand (COD), total nitrogen (TN), ammonia nitrogen (NH₄‐N), and total phosphorus (TP) were examined in the samples taken from the influent and effluent of leachate treatment plant, where Odayeri landfill leachate is treated. Obtained results showed that the treatment plant, which consisted of preanoxic biological treatment system, ultrafiltration (UF) and nanofiltration (NF) units were operating with high efficiency. Among the examined parameters during study, COD, TN, NH₄‐N, and TP were found to be treated at the rate of 99, 94.5, 99, and 93.8%, respectively. Landfilling is increasing rapidly in the world and this consequently brings the need of leachate treatment facilities. Therefore, this study is considered to be a guide for construction and operation stages of proposed new treatment plants.  相似文献   

Late Cenozoic uplift of the Amanos Mountains and incision of the Middle Ceyhan river gorge, southern Turkey; Ar–Ar dating of the Düziçi basalt   总被引：4，自引：0，他引：4  

Ali Seyrek  Tuncer Demir  Malcolm Pringle  Sema Yurtmen  Rob Westaway  David Bridgland  Anthony Beck  George Rowbotham 《Geomorphology》2008,97(3-4):321-355

Using the Ar–Ar technique, we have obtained the first numerical dates for the Pleistocene volcanism along the valley of the River Ceyhan in the Düziçi area of southern Turkey, in the western foothills of the Amanos Mountains. Our six dates indicate a single abrupt episode of volcanism at  270 ka. We have identified a staircase of 7 fluvial terraces, at altitudes of up to  230 m above the present level of the Ceyhan. Using the disposition of the basalt as an age constraint, we assign these terraces to cold-climate stages between marine oxygen isotope stages 16 and 2, indicating rates of fluvial incision, equated to surface uplift, that increase upstream through the western foothills of this mountain range at between 0.25 and 0.4 mm a^− 1. Extrapolation of these uplift rates into the axis of the range suggests that the entire  2300 m of present-day relief has developed since the Mid-Pliocene, a view that we confirm using numerical modelling. Since  3.7 Ma the Amanos Mountains have formed a transpressive stepover along the northern part of the Dead Sea Fault Zone, where crustal shortening is required by the geometry. Using a physics-based technique, we have modelled the overall isostatic response to the combination of processes occurring, including crustal thickening caused by the shortening, erosion caused by orographic precipitation, and the resulting outward flow of mobile lower-crustal material, in order to predict the resulting history of surface uplift. This modelling suggests that the effective viscosity of the lower crust in this region is in the range  1–2 × 10¹⁹ Pa s, consistent with a Moho temperature of  590 ± 10 °C, the latter value being in agreement with heat flow data. This modelling shows that the nature of the active crustal deformation is now understood, to first order at least, in this key locality within the boundary zone between the African and Arabian plates, the structure and geomorphology of which have been fundamentally misunderstood in the past.  相似文献   

Sealing Characteristics of Selected Grouts for Water Wells     

Tuncer B. Edil  Michael M. K. Chang  L. T. Lan  Thomas V. Riewe 《Ground water》1992,30(3):351-361

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Evolutionary Changes in Changhsingian Foraminifera: Extinction and Post-Extinction Recovery     

Demir ALTINER 《《地质学报》英文版》2013,87(Z1):897-899

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Experimental and numerical analyses of circular footing on geogrid-reinforced granular fill underlain by soft clay     

Ahmet Demir  Abdulazim Yildiz  Mustafa Laman  Murat Ornek 《Acta Geotechnica》2014,9(4):711-723

Experimental and numerical investigations into the bearing capacity of circular footing on geogrid-reinforced compacted granular fill layer overlying on natural clay deposit have been conducted in this study. A total of 8 field tests were carried out using circular model rigid footing with a diameter of 0.30 m. 3D numerical analyses were performed to simulate soil behavior using finite element program Plaxis 3D Foundation. The results from the FE analysis are in very good agreement with the experimental observations. It is shown that the degree of improvement depends on thickness of granular fill layer and properties and configuration of geogrid layers. Parameters of the experimental and numerical analyses include depth of first reinforcement, vertical spacing of reinforcement layers. The results indicate that the use of geogrid-reinforced granular fill layers over natural clay soils has considerable effects on the bearing capacity and significantly reduces the lateral displacement and vertical displacement of the footing.  相似文献