Dynamic Properties of Embankment Dams

Forced vibration test result are presented for two large embankment dams. The results are compared with an approximately three dimensional finite element analysis. In addition a semi-empirical fundamental period expression is developed for use in the interpretation of the available natural period data. The period expression developed is based on the shear wedge solution for an inhomogeneous medium and takes the effect of the third dimension into account

Expected Earthquake Losses to Buildings in Istanbul and Implications for the Performance of the Turkish Catastrophe Insurance Pool

The city of Istanbul will likely experience substantial direct and indirect losses as a result of a future large earthquake. This paper reports on the expected building losses in the city in terms of probable maximum and average annualized losses and discussed the results from the perspective of the compulsory earthquake insurance scheme operational in the country

Fuzzy logic approach for maximum wave runup estimation on rock armored slopes

Dökme-taş korumalı kıyı yapıları, arkasındaki alanı şiddetli dalga ve akıntılara karşı koruyan yüksek maliyetli yapılardır. Bu tür yapılarda, maksimum dalga tırmanması, tepe yüksekliğini belirleyen önemli bir parametredir. Kapsamlı literatür incelemesinden görülmüştür ki, regresyon analizleri neticesinde bulunan Van der Meer ve Stam yaklaşımı, dökme-taş korumalı kıyı yapılarının kret seviyesini hesaplamak için ilgili birçok şartnamede tavsiye edilmektedir. Oysa regresyon analizi neticesinde bulunan bu denklemin sağlaması gereken birtakım önkabuller vardır. Bu kabullerden herhangi biri sağlanmıyorsa regresyon analizi neticesinde elde etmiş olduğumuz denklem taraflı sonuç verir ve hatalıdır. Bu kabuller sırasıyla doğrusallık, normallik, şartlı dağılımın ortalamasının sıfır olması, eşit varyans, iç bağımlılık ve ölçülerin hatasız olmasıdır. Van der Meer ve Stam tarafından elde edilen laboratuar verilerinin istatistiki analizleri yukarıda verilen 6 şart için yapıldığında test sonuçları göstermiştir ki Van der Meer ve Stam denklemi, mevcut hali ile regresyon analizi yapılma şartlarını sağlayamamaktadır. Bu yüzden bu denklem taraflı ve hatalı sonuç vermektedir. Bu çalışmada içerisinde hiçbir önkabul barındırmayan Bulanık Mantık yönteminden yararlanılmıştır. Nümerik hata kriterleri ve grafik gösterimler, Bulanık Mantık yönteminin, Van der Meer ve Stam yaklaşımından daha gerçekçi ve daha pratik sonuçlar verdiğini göstermektedir. Ayrıca, Bulanık Mantık yönteminin kıyı benzerlik parametresine bağlı bir geçiş bölgesi bulunmamaktadır. Bundan dolayı, geliştirilen Bulanık Mantık modelin kullanımı kolay ve pratiktir. Bu yüzden, bu çalışmada önerilmiştir. Anahtar Kelimeler: Bulanık mantık, regresyon analizi, kret seviyesi.Extensive researches have been conducted about wave runup on smooth sloped breakwaters all over the world for a long time. Runup behavior on rough rock armored slopes are significantly different even under the same wave conditions. However, investigations on rock armored slopes are very limited. Rock armored slopes such as breakwaters and revetments are high-cost structures that defend the area behind them against severe wave attacks and strong currents. Wave runup is a crucial factor dictating the crest level of these structures. Van der Meer conducted extensive series of physical model tests under random sea states for investigating stability of rock armored slopes at Delft Hydraulics Laboratory, during which runup values are measured simultaneously. After qualitative review of various parameter influences concerning wave runup on impermeable, permeable and homogenous rock structures, Van der Meer and Stam proposed the most widely used formulae for the forecast of dimensionless 2% wave runup elevationas as function of surf similarity parameter by using regression analysis, which is also recommended by the U.S. Army Corps of Engineers, British standards. The regression model consists of two parts, namely linear and power functions.. Hence, it is necessary to consider a transition region which depends on the variable surf similarity parameter. Rock armored slopes are often designed according to the runup level exceeded by 2% of the incident waves, /Hs, on the front face of the coastal structure by using Van der Meer and Stam formulae. This parameter is defined as the vertical distance between the still-water level and the elevation exceeded by 2% percent of the runup values in the distribution. This means that, for every 100 waves running up a slope, two waves would have a runup elevation exceeding the level estimated by From the literature survey, it is seen that the two most important factors influencing runup phenomena on rock armored slopes are structure permeability and surf similarity parameter Since the relationships between wave runup and these parameters are complex, vague and uncertain in nature, it is quite difficult to adequately examine wave runup by conventional regressional approaches. Here, an attempt is made to construct various Takagi-Sugeno (TS, 1985) fuzzy models for predicting the 2% wave runup on rock armored slopes. The key task in developing a satisfactory forecasting model in the TS approach is the selection of appropriate input variables and numerical counts and types of Membership Functions of these variables, which determines the architecture of the model. Subsequently, the premise and consequent parameters are optimized by using ANFIS learning procedure. ANFIS, free of restrictive assumptions, optimizes premise and consequent parameters by gradient descent and least-squares methods, respectively, in order to best learn information about the dynamic system and does not contain any transition regions, as in the Meer and Stam equation depending on surf similarity parameter. In this study, many ANFIS models with different architectures are trained with the same 100 training data of Van der Meer and Stam. The training performance of each model is accomplished within a short time. They are compared with conventional empirical model of Van der Meer and Stam and with one another by using the 161 test data. As a result, the system with two inputs, namely structure permeability and surf similarity parameter, and each of which is assigned three trapezium MFs provides a smaller error compared to the empirical and other constructed ANFIS models and therefore is selected. In the constructed model, structure permeability  and surf similarity parameter variables are initially assigned three trapezium MFs with equal base widths. Then each parameter in the membership functions  in the premise part of fuzzy IF-THEN rules that changes the shapes of the membership function is set to an appropriate value to match the output data of the training data by using the back propagation algorithm. This leads Structure Permeability and Surf similarity parameter variables to different trapezium shapes. The developed fuzzy model with two inputs namely structure permeability and surf similarity parameter yielded the best result out of all constructed models and is proposed in this study. The presented model is validated by comparison with widely used empirical model of Meer and Stam recommended by the U.S. Army Corps of Engineers, using the experimental data-sets of Van der Meer and Stam. The verification process is obtained through scatter diagrams and two numerical error criterias. It was found that the Fuzzy Logic model produce better accuracy in performance than the Van der Meer and Stam's empirical model. Keywords: Fuzzy logic; regression analysis, crest level

Selection of ground motion prediction equations for the global earthquake model

Ground motion prediction equations (GMPEs) relate ground motion intensity measures to variables describing earthquake source, path, and site effects. From many available GMPEs, we select those models recommended for use in seismic hazard assessments in the Global Earthquake Model. We present a GMPE selection procedure that evaluates multidimensional ground motion trends (e.g., with respect to magnitude, distance, and structural period), examines functional forms, and evaluates published quantitative tests of GMPE performance against independent data. Our recommendations include: four models, based principally on simulations, for stable continental regions; three empirical models for interface and in-slab subduction zone events; and three empirical models for active shallow crustal regions. To approximately incorporate epistemic uncertainties, the selection process accounts for alternate representations of key GMPE attributes, such as the rate of distance attenuation, which are defensible from available data. Recommended models for each domain will change over time as additional GMPEs are developed

Seismic performance evaluation of traditional timber Hımış frames: capacity spectrum method based assessment

Timber constructions have been widely suggested to be seismically resistant based on post-disaster reconnaissance studies. This observation has, however, remained to a large extent anecdotal due to the lack of experimental work supporting it, especially for certain timber architectural forms, including traditional timber frame “hımış” structures. To fill this gap, the authors carried out an extensive full-scale testing scheme using frames of various geometrical configurations, tested under reverse-cyclic lateral loading with/without infill (brick and adobe) or cladding (bağdadi and şamdolma) (Aktas et al. in Earthq Spectra 30(4):1711–1732, 2014a, b). The tests concluded that hımış frames had high energy dissipation capabilities due mostly to nailed connections. Infill/cladding significantly helped improve stiffness and lateral load strength of the frames, and timber type did not seem to make a remarkable impact on the overall behaviour. The current paper, on the other hand, uses test data to calculate capacity/demand ratios based on capacity spectrum method and Eurocode 8 to elaborate more on the performance of “hımış” structures under seismic loading. The obtained results are discussed to draw important conclusions with regards to how frame geometry and infill/cladding techniques affect the overall performance

Modelling of earthquake hazard and secondary effects for loss assessment in Marmara (Turkey)

This study proposes the methodology for an innovative Earthquake Risk Assessment (ERA) framework to calculate seismic hazard maps in regions where limited seismo-tectonic information exists. The tool calculates the seismic hazard using a probabilistic seismic hazard analysis (PSHA) based on a MonteCarlo approach, which generates synthetic earthquake catalogues by randomizing key hazard parameters in a controlled manner. All the available data was transferred to GIS format and the results are evaluated to obtain a hazard maps that consider site amplification, liquefaction susceptibility and landslide hazard. The effectiveness of the PSHA methodology is demonstrated by carrying out the hazard analysis of Marmara region (Turkey), for which benchmark maps already exist. The results show that the hazard maps for Marmara region compare well with previous PSHA studies and with the National Building Code map. The proposed method is particularly suitable for generating hazard maps in developing countries, where data is not available or easily accessible

Copper-catalysed selective hydroamination reactions of alkynes

The development of selective reactions that utilize easily available and abundant precursors for the efficient synthesis of amines is a long-standing goal of chemical research. Despite the centrality of amines in a number of important research areas, including medicinal chemistry, total synthesis and materials science, a general, selective and step-efficient synthesis of amines is still needed. Here, we describe a set of mild catalytic conditions utilizing a single copper-based catalyst that enables the direct preparation of three distinct and important amine classes (enamines, α-chiral branched alkylamines and linear alkylamines) from readily available alkyne starting materials with high levels of chemo-, regio- and stereoselectivity. This methodology was applied to the asymmetric synthesis of ​rivastigmine and the formal synthesis of several other pharmaceutical agents, including ​duloxetine, ​atomoxetine, ​fluoxetine and ​tolterodine.National Institutes of Health (U.S.) (GM58160