As a relatively new means of transportation, the subway has become an important tool for the sustainable development of many cities. Being buried deep in soil under the weight of vital infrastructure, subway stations can be vulnerable to seismic excitations. Considering the high randomness of ground motions, it is important to research the failure probability and seismic performance of the subway station

According to the theories of wave propagation in visco-elastic continuum and Rayleigh-Love rod, a simplified model in axisymmetric conditions for the longitudinal vibration of large-diameter pipe pile (LDPP) in radially heterogeneous surrounding soil with viscous damping is presented. The relevant analytical solution for dynamic impedance at pile head is derived by using complex stiffness transfer

The extreme surges and waves generated in tsunamis can cause devastating damages to coastal infrastructures and threaten the intactness of coastal communities. After the 2004 Indian Ocean tsunami, extensive physical experiments and numerical simulations have been conducted to understand the wave attenuation of tsunami waves due to coastal forests. Nearly all prior works used solitary waves as the tsunami

The strong shallow earthquake with a moment magnitude (Mw) range between 6.6 and 7.0 according to different sources (AFAD, KOERI and USGS) took place at local time 14:51 on 30th October 2020, in Aegean Sea near Samos Island. According to the data given from Earthquake Department of the Disaster and Emergency Management Presidency (AFAD), the epicenter of the earthquake is 27.17km far away from the

The unconnected piles–caisson foundation (UPCF) consists of gravity caisson, mattress, and pile group. This foundation has been an attractive design for the mattress as it can reduce the seismic loads applied on the superstructure. However, a lack of understanding regarding its seismic behavior has hindered the application of this type of foundation. This paper reports on a series of slow cyclic tests

In seismic hazard studies, simulation techniques are exploited relatively less compared to other statistical methods. The main purposes of their use were merely scientific: either to reduce uncertainty in seismic hazard or to test the consistency of a forecast. Its limited exploitation in the field does not mean that the method could not be exploited further. Given sufficient data and with the right

This paper presents a closed-form analytical solution for the dynamic response of two independent SDOF oscillators standing on one flexible foundation embedded in an elastic half-space and excited by plane SH waves. The solution is obtained by the wave function expansion method and is verified by comparison with the results of the special cases of a rigid foundation and the published research result

Vegetated areas on the beach can reduce tsunami heights and reduce the loss of life and property damage in coasts. Thick trunks and tangled branches attenuate tsunami waves. In this study, a numerical model is developed based on the finite volume method for simulating tsunami flooding. This model is used to simulate the solitary wave run-up propagation on sloping beaches with and without vegetation

The effect of vehicle on the seismic responses of highway bridge has usually been neglected under the assumption that the possibility of vehicles crossing highway bridge or viaduct with a concurrent earthquake is extremely low. Furthermore, there is no in phase movement of vehicle and bridge was observed in past earthquake events. However, in the heavily trafficked urban area this is probably not the

The ground is simultaneously subjected to both horizontal and vertical motions during earthquakes; however, the majority of existing studies on seismic compression are still limited to the horizontal earthquake motions only. In this work, the objective is therefore to experimentally investigate the effects of multidirectional nature of load application on seismic compression of sand. Multiple series

There are three major fault zones in Turkey scattered around the country known as East Anatolian Fault (EAF), North Anatolian Fault (NAF) and Anatolian-Aegean Subduction Zone (AASZ). Last two decades, EAF has been rather quiescent compared with NAF. However, this quiescence was broken in the beginning of the millennium. The strong shaking was started in 2003 with Bingöl earthquake (Mw = 6.3) and the

To validate the seismic retrofitting of buildings quantitatively, we observed microtremors in the Uji campus buildings at Kyoto University. We compared the dynamic characteristics derived from the resonant frequency of microtremors in a five-story steel-frame structure and a three-story reinforced-concrete (RC) building before and after retrofitting. We calculated the weight of the building from the

The objective of this study is to propose a framework for evaluating the seismic fragility of bridge systems analytically taking into account correlations between component behaviors. To include coupled effects of component behaviors on system behavior, the second-order reliability approach is adopted. The damage states of the combined fragility are proposed based on system behavior characteristics

This study looks at the influence of plan-asymmetric properties on seismic performance of steel framed buildings by means of a comparative study. The seismic fragility curves of a symmetrical nine-story steel framed building and three asymmetric-plan buildings, which are the variations of the mentioned symmetrical building, are constructed through incremental dynamic analysis (IDA). The three asymmetric-plan

A great number of reinforced concrete building structures were damaged or collapsed during the earthquake that hit Sivrice district of Elazığ city located in the southwest of the Eastern Anatolia Region of Turkey on January 24, 2020. Magnitude of the earthquake were announced as Mw=6.5 and Mw=6.8 by Kandilli Observatory & Earthquake Research Institute (KOERI) and Earthquake Department of the Disaster

The performance of conventional rigid retaining wall under harmonic and transient ground motions is evaluated using three-dimensional finite element (FE) simulations. Rotation of wall about the base is found to be the predominant failure mechanism of the gravity retaining wall under seismic excitation. Earth pressure distribution corresponding to the peak ground acceleration is found to be nonlinear

Shallow footings are the most preferred foundations for buildings due to low cost and ease of construction. However, under seismic loads, these foundations may suffer excessive settlements, particularly when there is a risk of soil liquefaction. This paper explores the effectiveness of granular columns in mitigating the liquefaction-induced ground deformations under shallow foundations, using FLAC2D

b-value of the Gutenberg–Richter relation as an earthquake precursor depends on the tectonic setting features. This paper presents an alternative method to calculate b-value in the presence of characteristic earthquakes. The proposed equation is based on the maximum likelihood method applied on the probability density function of the characteristic earthquake model. Data from real and simulated catalogs

The Probabilistic Seismic Demand Analysis (PSDA) which is frequently implemented in the first generation performance-based earthquake engineering quantifies seismic behavior of a structure by computing mean annual frequency of exceeding a specific value of a desired demand parameter given all anticipated earthquakes. This framework, based on the total probability integration formula, provides a technical

Based on a rectangle underground station structure, two-dimensional finite element models are established in this study to explore the effectiveness of different seismic reduction and isolation measures for underground structure, where Davidenkov model is adopted to consider the soil nonlinearity and the underground structure is considered elastic. The performances of the seismic reduction and isolation

An earthquake is one of the most serious natural disasters to human beings. The damage from destructive earthquakes is enormous, and the predictions and estimations of earthquakes are urgent challenges in global science fields. In view of the shortcomings of the Markov chain model and the kriging methods in the estimation of the probabilities of the occurrence of earthquakes, the Markov chain–linear

In this research, we have implemented a numerical algorithm to identify the seismic wave parameters: P phase, S phase, amplitude, period and seismic signal duration. We have used the Matlab programming language and the digital signal processing toolbox to conduct the automatic picking of seismic signal parameters. As a mathematical tool, we have used the discrete Fourier transform to study the frequency

In both seismic design and probabilistic seismic-hazard analyses, site effects are typically characterized as the ratio of the response spectral ordinate on the ground surface to that on the bedrock based on the scaling law borrowed from the Fourier spectral ordinate. Recent studies have shown that different from the Fourier spectral ratio (FSR), the response spectral ratio (RSR) does not purely reflect

Several studies on liquefaction using physical model tests and numerical analysis have been conducted in recent years; however, few studies have investigated the effect of liquefaction-induced settlement on structures. Especially, this settlement seriously influences on gravity foundation during earthquake. This study aims to investigate the settlement of the surrounding ground of steel pipe sheet

To reduce the damage caused when a tsunami overflows coastal dikes, this study performs hydraulic experiments and numerical simulations and proposes a new method for slowing the tsunami by intentionally eroding parts of the ground. The effectiveness of the proposed method is assessed, velocity-reduction mechanism is clarified, and reduced tsunami velocity is predicted. Using crushed expanded polystyrene

In designing a numerical tool for simulating a wide variety of water waves, i.e. short to long waves, an accurate and robust wave model and numerical implementation are needed. Dispersion and nonlinearity are the two most important physical aspects that should be modeled accurately. To be applicable to simulate many coastal engineering applications, the numerical scheme should be capable of simulating

The purpose of this experimental study was to investigate the effects of a rectangular canal on the hydrodynamics of turbulent surges before and after the canal by implementing a series of physical experiments. A dam-break wave model was used to simulate the tsunami-like turbulent waves passing over a smooth and horizontal surface, in the presence and absence of a canal. Three canal depths of d=0.05

Some seismic design codes require to determine earthquake motions at ground surface, although we need sometimes a motion at engineering basement of ground. For example, it is necessary for optimal design of structures to introduce effects of soil-structure interaction and to input ground motions to engineering basement, which should satisfy the motions at surface required by a design code. This is

Aftershock records have a considerable effect on the results of collapse assessments conducted on buildings. Thus, they should be selected cautiously. As the number of recorded aftershocks is not sufficient, mainshock records are often utilized instead. In order to increase the correlation between the aftershock time history and the seismic response of a structure, this research intends to investigate

In this paper, a stochastic dynamic analysis method for cable-stayed bridges subjected to multi-dimensional and multi-supported earthquake and waves is established based on the pseudo-excitation method. The Monte Carlo method is used to analyze the influence of excitation nonlinearity on the bridge structure response, and the applicability of this method is verified. Stochastic response characteristic

This study discusses the composition and distribution of paleo-liquefaction structures, their triggering mechanisms, probable source and the dynamics of source faults expressed in the Kashmir basin (KB), NW Himalaya. Stratigraphic evidences of deformational structures along concomitant fault zones are highly preserved throughout the basin. The KB was frequently confronted with recurrent seismic activities

In this study, friction dampers (FDs) were placed at the top and bottom of a post-tensioned (PT) self-centering glulam (SCG) beam-to-column joint to dissipate earthquake energy. PT tendons were installed in two externally elongated slots at the centroid of the beam to provide the system with self-centering capacity so that the system can return to its original position after an earthquake. Theoretical

Earthquake source parameters such as slip distribution and slip rate are useful information for understanding the physical processes behind earthquakes. The isochrone back-projection method, or isochrone-BPM, is one of the methods used to obtain slip distribution in the fault plane by incorporating the isochrone concept with back-projection method. Isochrone-BPM has advantages in its ease of implementation

The improved mega sub-controlled structure system (MSCSS) significantly reduced the building responses and improved the control effectiveness as compared to conventional mega substructure (MSS). However, since the MSCSS is designed to resist future earthquakes, the seismic risk assessment of the structure remains a significant concern. In this study, the seismic risk analysis of MSCSS is performed

Tsunami databases contain general information of historical tsunamis, which provides valuable and fundamental data to tsunami-related researches. Nevertheless, before adopting the information stored in various tsunami databases, users should be familiar with these databases’ individual features due to their inhomogeneity in data storage. To this end, a comprehensive review of the worldwide existing

In recent years, hybrid rocking columns incorporating post-tensioned (PT) tendons and energy dissipation devices become prevalent on account of the superior self-centering capacity. In this paper, the simplified analysis method based on interface section analysis is employed to conduct parametric analyses on the hybrid rocking columns with external buckling-restrained devices, which are adopted as

Physical experiments are conducted to study the interaction between the tsunami-like waves and the horizontal plate. The surface evolution and wave-induced loads are measured to explore the hydrodynamic characteristics when different waves are employed to simulate the tsunami. The solitary wave, surge wave, and undular bore are generated in laboratory as the simplification of the offshore tsunami wave

North-East India (NEI) has a long history of devastating earthquakes due to the complicated tectonic setting of the region. A shortage of sufficient recorded time-histories from the region calls for a synthesis of accelerograms for dynamic analyses. In this study, a novel Joint Time-Frequency Analysis (JTFA) technique is adopted for the synthesis of accelerograms, considering the non-stationary behavior

In this paper, a novel restrainer called steel ring restrainer (SRR) is proposed to prevent the unseating of bridges. The restrainer is comprised of a steel ring, an upper guiding pulley, a downward guiding pulley, and two connections. The SRR can provide different stiffnesses under different seismic excitations. The SRR is not activated under daily load but provides smaller stiffness in small and

New Delhi is a city affected by near/far-field earthquakes, where underground metro construction activities have been undertaken since the early 2000s. Due to the seismic effects, these structures are designed by conventional force/displacement methods. The present study validates the efficacy of these methods, numerically. For this, varying geotechnical conditions in static and seismic cases were

Many cities in the Philippines are situated near fault systems that can generate large magnitude of earthquakes. This paper describes the development of a city seismic response analysis approach for Metro Manila’s low- to mid-rise RC structures using frame models which are generated from GIS feature or BIM data. To create the three-dimensional (3D) models, features and structural details from BIM are

Traditional models assuming a vertically uniform structure of the horizontal flow velocity and neglecting the vertical velocity distribution cannot accurately describe the complex boundary layer flow features in the dam-break induced wave tip region. Based on the assumption that the horizontal velocity profile in the wave tip region follows a vertically parabolic distribution with shear extending to

Kappa (κ) describes the amplitude decay of acceleration Fourier spectrum at high frequencies. Using the records of K-NET and KiK-net stations during the mainshock of the 2011 Great East Japan Earthquake, we examine if the typical measurement method of κ can be extended to this size of event and how propagation path and site condition affect κ. The strength of the linear relationship between epicentral

An experimental study was carried out to investigate the tsunami surge impacts on small balls climbing on different slopes. Dam-break flows were generated in a flume to simulate tsunami surge. The water surface profiles at the sluice gate were observed, the tsunami inundation height and the surge velocity in the flume were measured, and the maximum climbing heights of small balls on different slopes

Tsunamis are generated primarily by the vertical displacement of the seafloor if the seafloor is flat. If the seafloor is slanted, the horizontal motion also contributes to the generation of tsunamis. A previous study proposed that such effects can be estimated by simply calculating the elevation of water due to the horizontal displacement of the slope. Two more studies later argued that the horizontal

To estimate seismic demand and capacity of structures, it has been suggested by researchers that Incremental Dynamic Analysis (IDA) is one of the most accurate methods. Although this method shows the most accurate response of the structure, some problems, such as difficulty in modeling, time-consuming analysis and selection of the earthquake records, encourage researchers to find some ways to estimate

Structures, such as bridges, pipelines which are supported at multiple places, will be subjected to differential excitation. A significant change in the correlation of the motions between the two supports is due to the combined effects of wave passage, coherency loss and local soil conditions. In the classical formulation, the response is divided into quasi-static and dynamic components and the latter

Reducing the risk of structural damage due to earthquake-induced liquefaction in new and existing buildings is a challenging problem in geotechnical engineering. Drainage countermeasure techniques against liquefaction have been studied over the last decades with an emphasis on the use of vertical drains. This technique aims to allow a rapid dissipation of excess pore pressures generated in the soil

The seismic design of the structures is carried out by technical regulations and codes in free-field conditions (regardless of underground cavities). With the availability of tunnels and the complex interaction between the tunnel and the aboveground structures, which may be contemplated wrongly, it could be dangerous for over ground buildings and structures. Consequently, the examination of the underground

A series of shaking table tests were conducted on reinforced slopes to study the slope dynamic characteristics. The influence of concrete-canvas tilt degrees on the seismic response was studied. By considering the effects of different concrete-canvas tilt degrees, the seismic responses of the reinforced slopes were analyzed, along with the accelerations, crest settlements, and horizontal displacements

The effectiveness of coastal vegetation as a barrier to mitigate a tsunami greatly depends on the magnitude of tsunami and vegetation structure. This paper summarizes a series of laboratory experiments that investigated the upstream flow structure and energy loss due to a hydraulic jump in a steady super-critical flow. The characteristics of the jump were determined against vegetation of variable density

The lately proposed mega sub-controlled structure (MSCSS) remarkably improved the seismic resistance ability and reduced vibration effects much more than the mega substructure (MSS). However, the controlling effectiveness and its optimization remain a significant concern. In this paper, a new configuration of MSCSS is analyzed in which viscous dampers are optimally arranged between mega-frame and substructural

On September 28, 2018, Palu Earthquake caused tremendous damage to the coastal area of Palu, Central Sulawesi, Indonesia. The epicenter was located at 27km northeast from Donggala Beach with a 10km depth. The magnitude of the earthquake was recorded at 7.4. This study assessed the tsunami overland characteristics and its outcome on the coastal area of Palu. The analysis was conducted based on satellite

Tensile cracking at the position where geometry changes is a typical failure mode of gravity dams under strong earthquakes. Steel reinforcement has been proposed to reduce the degree of dam cracking. In this paper, a nonlinear model is presented to consider the interaction effect between the steel reinforcement and the dam concrete in a combined concrete damage model and distributed-steel model. In

One way for decreasing the effect of pounding is to set the separation gap between two adjacent buildings. On the one hand, earthquakes in earthquake-prone zones often occur as a chain of successive earth movements in the form of foreshock, mainshock and aftershock. On the other hand, the existence of soft story in the lowest story of the structure is the most common type of irregularity in lateral

Three hundred and thirty-five local earthquakes were processed and the attenuation properties of the crust in the Racha region were investigated using the records of seven seismic stations. We have estimated the quality factors of coda waves (Qc) and the direct S waves (Qs) by the single back scattering model and the coda normalization methods, respectively. The Wennerberg’s method has been used to

In this study, two types of novel box connections were developed to connect precast concrete (PC) columns and to ensure load transfer integrity. Cyclic loading tests were conducted to investigate the seismic behavior of the PC columns with proposed connections as well as the feasibility and reliability of novel box connections. The failure mode, hysteretic behavior, bearing capacity, ductility, stiffness

An advanced direct half-plane time-domain boundary element method (BEM) was applied to obtain the seismic response of a linear elastic irregular surface including periodically distributed semi-sine shaped valleys subjected to propagating obliquely incident plane SH waves. After developing the method for complex multiple surface topographies, some verification examples were solved and compared with

Many beaches in Penang island were severely inundated by the 26 December 2004 Indian Ocean mega tsunami with 57 deaths recorded. It is anticipated that the next big tsunami will cause even more damages to beaches in Penang. Hence, developing community resilience against the risks of the next tsunami is essential. Resilience entails many interlinked components, beginning with a good understanding of

Tsunami is one of the world’s most dangerous marine disaster. In this paper, freely available remote sensing data are applied to study the hazard, vulnerability, and evacuation in the event that a tsunami strikes the district of Tianya in the city of Sanya. Tsunami inundation is calculated using a tsunami numerical model, and the tsunami vulnerability and evacuation in the inundation area are analyzed