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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.
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
4.
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
5.
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
6.
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
7.
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
8.
9.
崎头洋附近群岛水域泥沙特征及悬沙来源分析 总被引：1，自引：0，他引：1
依据实测水文泥沙资料分析舟山群岛南部崎头洋附近海域的悬沙与底沙特征,建立该水域二维潮流数学模型,同时根据底沙及悬沙的粒径分布和潮流的运动路径对该海域的悬沙来源做进一步分析.指出崎头洋附近群岛海域的悬沙除部分来源于潮汐动力作用下的底沙起动再悬浮之外,主要是杭州湾附近灰鳖洋水域的泥沙在潮汐动力作用下经群岛西北方向水道进入群岛内部水域的,进而在潮动力作用下经由东南方向水道进入东海及象山港附近水域. 相似文献
10.
An experimental study was carried out to determine the effects of a coastal forest on tsunami run-up heights. The beach was built as a natural sandy beach at laboratory scale. The coastal forest model was constructed using artificial trees (FM–I) and cylindrical timber sticks (FM–II). Artificial trees were placed on a 1:5 slope in three different layouts: rectilinear, staggered, and dense rectilinear. It was shown that in the case when the trees were placed in the dense rectilinear pattern and close to the still water level (SWL), the run-up height was reduced by approximately 45% compared with the case without trees. After evaluation of the experimental results, the parameters that affect the run-up height were determined. These parameters were written as a dimensionless group using Buckingham's Pi theorem. An extensive regression analysis was carried out and equations proposed. Furthermore, all experiments were repeated with a slope of 1:3.5 to verify the proposed equations. The experimental results were compared with the results of the proposed equations, and it was shown a good agreement between the results. 相似文献