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The use of high-speed railway network is becoming widespread in Turkey. High-speed passenger trains with a maximum of 250–300-km/h speed and a maximum of 22.5-t force axle loads can generate high levels of ground-borne vibration, especially in the high frequencies. Railway traffic on soft soil deposits for which measured shear velocity value is as low as 200 km/h can cause structural damage to the surrounding buildings. There has been a substantial increase in the studies on ground-borne vibration problems in the vicinity of the railway lines due to the passage of high-speed trains in recent years. The aim of this study is to evaluate the effect of the high-speed train-induced environmental vibration in terms of human exposure to vibration in buildings and effects of vibration on structures according to the USA, Federal Transportation Administration (FTA) and German (DIN 4150-Parts 2 and 3) norms by using the verified finite element model based on in situ measurements. The 2-D finite element model dealt under the plane-strain condition with simulation of the moving load fully considers the vibrational energy dissipation by using viscous boundaries along the truncated interfaces of the infinite soil domain. In order to make a comparison with the threshold values defined in German and FTA standards, velocity response curves and frequency content at the measurement points where the accelerometers are located in the free field are obtained numerically for different soil types according to Turkish Earthquake Standard (TBDY 2018). Generally, it is observed that the unfavorable effects on human perception and building safety are increased when the ground rigidity underlying of building foundation has decreased. [ABSTRACT FROM AUTHOR]

The goal of this study is to provide a stochastic method to investigate the effects of the randomness of soil properties due to their natural spatial variability on the response spectra spatial variation at sites with varying conditions. For this purpose, Monte Carlo Simulations are used to include the variability of both incident ground motion and soil parameters in the response spectra by mean of an appropriate coherency loss function and a site-dependent transfer function, respectively. The approach is built on the assumption of vertical propagation of SH type waves in soil strata with uncertain parameters. The response spectra are obtained by numerical integration of the governing equation of a single-degree-of-freedom (SDOF) system under non-stationary site-dependent and spatially varying ground motion accelerations simulated with non-uniform spectral densities and coherency loss functions. Numerical examples showed that randomness of soil properties significantly affects the amplitudes of the response spectra, indicating that as the heterogeneity induced by the randomness of the parameters of the medium increases, the spectral ordinates attenuate. [ABSTRACT FROM AUTHOR]

On October 23, 2011, a magnitude of Mw 7.2 earthquake struck the Van province in eastern Turkey which caused approximately 600 life loss and 4,000 injured people. Although the recorded peak ground accelerations were relatively low (0.15-0.2 g) compared with that of other recent destructive Turkish earthquakes and the code-based design response spectrum, a large number of reinforced concrete buildings with 4-6 stories and non-engineered masonry buildings were either heavily damaged or collapsed in the region. Based on the post-earthquake technical inspections, the goal of this paper is to introduce major reasons for structural damages in the disaster area and to discuss these failures along with the approaches given in the design code which is renewed after August 17, 1999 Marmara Earthquake. Some remarkable lessons learned from earthquake-induced failures and damages specific to building construction techniques are presented in this paper. [ABSTRACT FROM AUTHOR]

This research comprises a series of shaking table tests and finite element analyses of scaled soil-foundation model to determine the dynamic interaction effects between the foundation and the underlying soil. The purpose of this work is to specify a realistic geometric scaling coefficient for test model to be used in a small-capacity shaking table. The scaling factor addressed in this study involves not only geometric similarity but also kinematic and dynamic similarity with the real system. The free-field soil response under different earthquake excitations for both real system and scaled test model was directly performed by using 2D finite element method under plane-strain conditions. The kinematic interaction of the shallow foundation slab on free-field motion was also examined. In this computational model, the behavior of the soil medium is idealized by linear elastic-perfectly plastic assumption with a yield surface according to Mohr-Coulomb failure criterion. Two different earthquake acceleration records as Chi-Chi (1999) and Loma Prieta (1989) have been carried out at the bedrock level of the soil-foundation system for this study. By comparing the results of the numerical analysis with data from the laboratory tests, the proposed geotechnical model can properly simulate the seismic response of the full-scale real system. It can be concluded that the kinematic interaction effects are negligible in the low frequencies. It should be noted that the local soil properties have considerably amplified the earthquake response of the free-field motions in comparison to the bedrock excitations. [ABSTRACT FROM AUTHOR]