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1.
The research area that is in the north of Istanbul (Turkey) and it is a land of open pit coal mining residuals reclaimed and turned to forest in 1988–1989. The materials that are open pit mine spoils are formed by sandy loam, sandy clay loam, heavy loam and clay (noncalcareous Pliocene I sediments). Pseudoacacia (Robinia pseudoacacia), Maritima Pine (Pinus pinaster) and Stone Pine (Pinus pinea) are planted on these materials. The aims of this research were to determine the strength of the material provided by tree roots and evaluate the performance of the forestation practices at lands especially where open pit coal mining spoil (residual) materials piled up. The research has been performed at two stages. The first one was hydro-mechanical effect concerned about material moisture depletion as a result of transpiration and the second one was bio-mechanical effects due to strength parameters of the roots and their growth pattern within the material. All results were evaluated in relation to tensile strength and displacement curves due to pre and post failure behaviors of materials and root systems. The results showed the increase of the displacement of the material was the significant indicator of the bio-mechanics tensile strength of the material provided by the tree roots. The fast growing type of tree roots have stabilized the material up to a depth for 80–100 cm by covering the coal residual materials within 12 years. 相似文献
2.
In this study, some toxic metal such as Pb, Cd and Hg analyzes have been done in the nearshore surface sediments. Sediment samples have been collected from five parts from the European and Anotolian Shores of the Bosphorus during 2003-2004. Total Pb, Cd and Hg contents vary between <0.01μgg(-1) and 238μgg(-1); <0.01μgg(-1) and 0.92μgg(-1); 0.001μgg(-1) and 0.45μgg(-1), respectively. Contamination Factor (CF) values of Pb and Cd range between 1 and 3 whilst CF values of Hg are lower than 1 in all the stations. It means that there are no Hg metal enrichment by natural or anthropogenic inputs contrary to moderately contamination for Pb and Cd metals throughout the Bosphorus sediments. 相似文献
3.
A series of tests were conducted to investigate the improvement of damping properties of clay samples with geosynthetic inclusions.
Flexible thermoplastic polymer synthetics improve damping properties of clay samples. Resonant column tests were conducted
to measure the low strain shear modulus and damping ratio of laboratory prepared synthetic inclusion clay specimens. The shear
modulus and damping ratio of the reinforced clay samples were investigated considering geosynthetic type (geotextile and geomembrane),
number of geosynthetic sheets, and confining pressure. The test results demonstrated that the geomembrane and the number of
geosynthetic sheets significantly improved the shear modulus and damping ratio of reinforced clay samples compared with those
of the unreinforced clay samples. 相似文献
4.
Nuray Tokgöz 《Environmental Earth Sciences》2010,59(7):1559-1567
The concept of sustainable development has gained wide acceptance in the fields of mining and environmental studies. Mining
is a temporary activity, but its impact on the environment persists long after mine closure. The aim of this research is to
investigate the effect of land-use change on the stability of the Agacli landslide, northern coastal part of the Istanbul
(Turkey), spanning periods of mining, reclamation, and afforestation. Geological and geophysical surveys were performed to
determine the effects of erosion on the landslide. To assess the possibility of water responsible for triggering a landslide–gully
complex, the dynamic elastic parameters of the field are calculated. Field observations indicate that surface erosion and
gully development have ceased in the afforested area; however, gullies in non-forested areas continue to increase in size
and depth. Uncontrolled surface water and water from stock watering ponds have trigger erosion and rapid sedimentation of
the landslide–gully complex, resulting in over-steepening and enhanced landslide activity on the flanks of the main slide. 相似文献
5.
An Incremental Response Spectrum Analysis Procedure Based on Inelastic Spectral Displacements for Multi-Mode Seismic Performance Evaluation 总被引:1,自引:0,他引:1
M. Nuray Aydinoğlu 《Bulletin of Earthquake Engineering》2003,1(1):3-36
The so-called Nonlinear Static Procedure (NSP) based on pushover analysis has been developed in the last decade as a practical
engineering tool to estimate the inelastic response quantities in the framework of performance-based seismic evaluation of
structures. However NSP suffers from a major drawback in that it is restricted with a single-mode response and therefore the
procedure can be reliably applied only to the two-dimensional response of low-rise, regular buildings. Recognizing the continuously
intensifying use of the pushover-based NSP in the engineering practice, the present paper attempts to develop a new pushover
analysis procedure to cater for the multi-mode response in a practical and theoretically consistent manner. The proposed Incremental
Response Spectrum Analysis (IRSA) procedure is based on the approximate development of the so-called modal capacity diagrams,
which are defined as the backbone curves of the modal hysteresis loops. Modal capacity diagrams are used for the estimation
of instantaneous modal inelastic spectral displacements in a piecewise linear process called pushover-history analysis. It
is illustrated through an example analysis that the proposed IRSA procedure can estimate with a reasonable accuracy the peak
inelastic response quantities of interest, such as story drift ratios and plastic hinge rotations as well as the story shears
and overturning moments. A practical version of the procedure is also developed which is based on the code-specified smooth
response spectrum and the well-known equal displacement rule.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
6.
Tsunami run-up height is a significant parameter for dimemsions of coastal structures.In the present study,tsunami run-up heights are estimated by three different Artificial Neural Network (ANN) models,i.e.Feed Forward Back Propagation (FFBP),Radial Basis Functions (RBF) and Generalized Regression Neural Network (GRNN).As the input for the ANN configuration,the wave height (H) values are employed.It is shown that the tsunami run-up height values are closely approximated with all of the applied ANN methods.The ANN estimations are slightly superior to those of the empirical equation.It can he seen that the ANN applications are especially significant in the absence of adequate number of laboratory experiments.The restdts also prove that the available experiment data set can he extended with ANN simulations.This may be helpful to decrease the burden of the experimental studies and to supply results for comparisons. 相似文献
7.
Zeynep Akbulut Samed Özdemir Hayrettin Acar Fevzi Karsli 《Journal of the Indian Society of Remote Sensing》2018,46(12):2057-2068
Automatic building extraction is an important topic for many applications such as urban planning, disaster management, 3D building modeling and updating GIS databases. Its approaches mainly depend on two data sources: light detection and ranging (LiDAR) point cloud and aerial imagery both of which have advantages and disadvantages of their own. In this study, in order to benefit from the advantages of each data sources, LiDAR and image data combined together. And then, the building boundaries were extracted with the automated active contour algorithm implemented in MATLAB. Active contour algorithm uses initial contour positions to segment an object in the image. Initial contour positions were detected without user interaction by a series of image enhancements, band ratio and morphological operations. Four test areas with varying building and background levels of detail were selected from ISPRS’s benchmark Vaihingen and Istanbul datasets. Vegetation and shadows were removed from all the datasets by band ratio to improve segmentation quality. Subsequently, LiDAR point cloud data was converted to raster format and added to the aerial imagery as an extra band. Resulting merged image and initial contour positions were given to the active contour algorithm to extract building boundaries. In order to compare the contribution of LiDAR to the proposed method, the boundaries of the buildings were extracted from the input image before and after adding LiDAR data to the image as a layer. Finally extracted building boundaries were smoothed by the Awrangjeb (Int J Remote Sen 37(3): 551–579. https://doi.org/10.1080/01431161.2015.1131868, 2016) boundary regularization algorithm. Correctness (Corr), completeness (Comp) and accuracy (Q) metrics were used to assess accuracy of segmented building boundaries by comparing extracted building boundaries with manually digitized building boundaries. Proposed approach shows the promising results with over 93% correctness, 92% completeness and 89% quality. 相似文献
8.
Adaptive neuro-fuzzy inference system (ANFIS) and artificial neural network (ANN) models have been extensively used to predict
different soil properties in geotechnical applications. In this study, it was aimed to develop ANFIS and ANN models to predict
the unconfined compressive strength (UCS) of compacted soils. For this purpose, 84 soil samples with different grain-size
distribution compacted at optimum water content were subjected to the unconfined compressive tests to determine their UCS
values. Many of the test results (for 64 samples) were used to train the ANFIS and the ANN models, and the rest of the experimental
results (for 20 samples) were used to predict the UCS of compacted samples. To train these models, the clay content, fine
silt content, coarse silt content, fine sand content, middle sand content, coarse sand content, and gravel content of the
total soil mass were used as input data for these models. The UCS values of compacted soils were output data in these models.
The ANFIS model results were compared with those of the ANN model and it was seen that the ANFIS model results were very encouraging.
Consequently, the results of this study have important findings indicating reliable and simple prediction tools for the UCS
of compacted soils. 相似文献
9.
Assessment of excavatability,abrasivity and slope stability in a sandstone quarry in Istanbul,Turkey
Selman Er Murat Yilmaz Altay Ertin Atiye Tugrul Nuray Tokgöz 《Journal of the Geological Society of India》2017,89(5):581-588
The Cebeci region is characterized by outcrops of Carboniferous sandstone, including diabase dykes. This region is very important area for aggregate production in Istanbul, Turkey. The aim of this study is to determine the engineering geological properties of sandstones to assess the excavatability, abrasivity and stability of cut slopes in a quarry site. Firstly, the sandstone samples were used to determine their petrographical and mineralogical characteristics. Then, physico-mechanical tests were performed on these samples. In order to determine rock mass properties, scan-line surveys were performed, and the major orientations of discontinuities were analyzed through the stereographic projection technique. Kinematical analyses were also made to determine the potential failures at the quarry site. According to the results obtained, excavatability is changed from easy ripping to hard ripping on sandstones; the carbonated sandstone is less abrasive than other sandstones. Based on the field studies and stability analyses of the cut slopes, optimum slope geometry and necessary support measures, such as wire mesh and rock fall barriers, are suggested. 相似文献
10.
Comparing Loss Estimation with Observed Damage: A Study of the 1999 Kocaeli Earthquake in Turkey 总被引:4,自引:0,他引:4
Robin Spence Julian Bommer Domenico del Re Juliet Bird Nuray Aydinoğlu Shigeko Tabuchi 《Bulletin of Earthquake Engineering》2003,1(1):83-113
Loss estimation from future earthquakes is of growing importance in planning earthquake protection strategies in high-risk
areas. Loss models based on the spectral displacement approach are now widely used because of generally acknowledged deficiencies
in earlier approaches using macroseismic intensity or peak ground-motion parameters. However, there has been to date rather
little earthquake damage data by which the new generation of models can be assessed and which can be used to calibrate the
parameters involved. The availability of several detailed damage surveys carried out following the 1999 Kocaeli earthquake
in Turkey, provides a rare opportunity for such an assessment. In this paper the losses which would be predicted from two
different approaches to loss assessment – one using predicted macroseismic intensity, the other using the spectral displacement
method – are compared with actual observed losses in the Kocaeli event at two different locations where surveys were carried
out. One of these sites was very close to the surface fault rupture (< 3 km distance), the other at a distance of about 4.5 km.
It is shown that the predictive methods available generally overestimated the losses at these distances, and a number of possible
reasons for these discrepancies are considered. The sensitivity of loss estimates to variations in the key parameters governing
the estimation in each case are explored, in particular with respect to modifications in the parameters of the attenuation
relationships and the vulnerability parameters. The implications of these results for estimating future losses are discussed.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献